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Sample records for quark mass dependence

  1. Hadron Spectra and Quark Mass Dependence in Holographic QCD

    NASA Astrophysics Data System (ADS)

    Hashimoto, K.

    Hadron masses and their quark-mass dependence are imporatant observablesin strongly coupled QCD. We apply holography, a string theory technique, to this problem, and find a qualitative coincidence with observed data of baryon spectra. This talk, presented on 9th Feruary 2010 in ``NFQCD'' workshop at YITP, is based on three papers written with my collaborators [K.~Hashimoto, T.~Hirayama, F.~L.~Lin and H.~U.~Yee, J. High Energy Phys. 07 (2008), 089, arXiv:0803.4192. K.~Hashimoto, T.~Hirayama and D.~K.~Hong, Phys. Rev. D 81 (2010), 045016, arXiv:0906.0402. K.~Hashimoto, N.~Iizuka, T.~Ishii and D.~Kadoh, Phys. Lett. B 691 (2010), 65, arXiv:0910.1179.

  2. Dilepton production as a useful probe of quark gluon plasma with temperature dependent chemical potential quark mass

    NASA Astrophysics Data System (ADS)

    Kumar, Yogesh; Singh, S. Somorendro

    2016-07-01

    We extend the previous study of dilepton production using [S. Somorendro Singh and Y. Kumar, Can. J. Phys. 92 (2014) 31] based on a simple quasiparticle model of quark-gluon plasma (QGP). In this model, finite value of quark mass uses temperature dependent chemical potential the so-called Temperature Dependent Chemical Potential Quark Mass (TDCPQM). We calculate dilepton production in the relevant range of mass region. It is observed that the production rate is marginally enhanced from the earlier work. This is due to the effect of TDCPQM and its effect is highly significant in the production of dilepton.

  3. Light quark mass dependence of the X(3872) in X

    NASA Astrophysics Data System (ADS)

    Jansen, M.; Hammer, H.-W.; Jia, Yu

    2015-10-01

    The X(3872) is a charmonium-like hadron with a mass close to the overline D ^0 D^{*0} threshold. It was first observed in 2003 by the Belle Collaboration and confirmed shortly after by the CDF collaboration. The quantum numbers were recently determined by the LHCb experiment to be JPC = 1++3. Yet, the nature of the X(3872) is not fully understood. In future, lattice QCD calculations should be able to obtain observables and are expected to contribute to a better understanding of the X...

  4. Heavy quark masses

    NASA Technical Reports Server (NTRS)

    Testa, Massimo

    1990-01-01

    In the large quark mass limit, an argument which identifies the mass of the heavy-light pseudoscalar or scalar bound state with the renormalized mass of the heavy quark is given. The following equation is discussed: m(sub Q) = m(sub B), where m(sub Q) and m(sub B) are respectively the mass of the heavy quark and the mass of the pseudoscalar bound state.

  5. Quark-mass dependence of the three-flavor QCD phase diagram at zero and imaginary chemical potential: Model prediction

    SciTech Connect

    Sasaki, Takahiro; Sakai, Yuji; Yahiro, Masanobu; Kouno, Hiroaki

    2011-11-01

    We draw the three-flavor phase diagram as a function of light- and strange-quark masses for both zero and imaginary quark-number chemical potential, using the Polyakov-loop extended Nambu-Jona-Lasinio model with an effective four-quark vertex depending on the Polyakov loop. The model prediction is qualitatively consistent with 2+1 flavor lattice QCD prediction at zero chemical potential and with degenerate three-flavor lattice QCD prediction at imaginary chemical potential.

  6. Top Quark Mass Measurements

    SciTech Connect

    Heinson, A.P.; /UC, Riverside

    2006-08-01

    First observed in 1995, the top quark is one of a pair of third-generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV, about 40 times heavier than its partner, the bottom quark. The CDF and D0 collaborations have identified several hundred events containing the decays of top-antitop pairs in the large dataset collected at the Tevatron proton-antiproton collider over the last four years. They have used these events to measure the top quark's mass to nearly 1% precision and to study other top quark properties. The mass of the top quark is a fundamental parameter of the Standard Model, and knowledge of its value with small uncertainty allows us to predict properties of the as-yet-unobserved Higgs boson. This paper presents the status of the measurements of the top quark mass.

  7. Top quark mass measurements

    SciTech Connect

    Hill, Christopher S.; /UC, Santa Barbara

    2004-12-01

    The top quark, with its extraordinarily large mass (nearly that of a gold atom), plays a significant role in the phenomenology of EWSB in the Standard Model. In particular, the top quark mass when combined with the W mass constrains the mass of the as yet unobserved Higgs boson. Thus, a precise determination of the mass of the top quark is a principal goal of the CDF and D0 experiments. With the data collected thus far in Runs 1 and 2 of the Tevatron, CDF and D0 have measured the top quark mass in both the lepton+jets and dilepton decay channels using a variety of complementary experimental techniques. The author presents an overview of the most recent of the measurements.

  8. Top Quark Mass Measurements

    SciTech Connect

    Heinson, A. P.

    2006-11-17

    First observed in 1995, the top quark is one of a pair of third-generation quarks in the Standard Model of particle physics. It has charge +2/3e and a mass of 171.4 GeV, about 40 times heavier than its partner, the bottom quark. The CDF and DO collaborations have identified several hundred events containing the decays of top-antitop pairs in the large dataset collected at the Tevatron proton-antiproton collider over the last four years. They have used these events to measure the top quark's mass to nearly 1% precision and to study other top quark properties. The mass of the top quark is a fundamental parameter of the Standard Model, and knowledge of its value with small uncertainty allows us to predict properties of the as-yet-unobserved Higgs boson. This paper presents the status of the measurements of the top quark mass. It is based on a talk I gave at the Conference on the Intersections of Particle and Nuclear Physics in Puerto Rico, May 2006, which also included discussion of measurements of other top quark properties.

  9. Higgs Boson Pair Production in Gluon Fusion at Next-to-Leading Order with Full Top-Quark Mass Dependence

    NASA Astrophysics Data System (ADS)

    Borowka, S.; Greiner, N.; Heinrich, G.; Jones, S. P.; Kerner, M.; Schlenk, J.; Schubert, U.; Zirke, T.

    2016-07-01

    We present the calculation of the cross section and invariant mass distribution for Higgs boson pair production in gluon fusion at next-to-leading order (NLO) in QCD. Top-quark masses are fully taken into account throughout the calculation. The virtual two-loop amplitude has been generated using an extension of the program GoSam supplemented with an interface to Reduze for the integral reduction. The occurring integrals have been calculated numerically using the program SecDec. Our results, including the full top-quark mass dependence for the first time, allow us to assess the validity of various approximations proposed in the literature, which we also recalculate. We find substantial deviations between the NLO result and the different approximations, which emphasizes the importance of including the full top-quark mass dependence at NLO.

  10. Higgs Boson Pair Production in Gluon Fusion at Next-to-Leading Order with Full Top-Quark Mass Dependence.

    PubMed

    Borowka, S; Greiner, N; Heinrich, G; Jones, S P; Kerner, M; Schlenk, J; Schubert, U; Zirke, T

    2016-07-01

    We present the calculation of the cross section and invariant mass distribution for Higgs boson pair production in gluon fusion at next-to-leading order (NLO) in QCD. Top-quark masses are fully taken into account throughout the calculation. The virtual two-loop amplitude has been generated using an extension of the program GoSam supplemented with an interface to Reduze for the integral reduction. The occurring integrals have been calculated numerically using the program SecDec. Our results, including the full top-quark mass dependence for the first time, allow us to assess the validity of various approximations proposed in the literature, which we also recalculate. We find substantial deviations between the NLO result and the different approximations, which emphasizes the importance of including the full top-quark mass dependence at NLO. PMID:27419563

  11. Quark-mass dependence of the baryon ground-state masses

    NASA Astrophysics Data System (ADS)

    Semke, A.; Lutz, M. F. M.

    2012-02-01

    We perform a chiral extrapolation of the baryon octet and decuplet masses in a relativistic formulation of chiral perturbation theory. A partial summation is assumed as implied by the use of physical baryon and meson masses in the one-loop diagrams. Upon a chiral expansion, our results are consistent with strict chiral perturbation theory at the next-to-next-to-next-to-leading order. All counter terms are correlated by a large-Nc operator analysis. Our results are confronted with recent results of unquenched three-flavor lattice simulations. We adjust the parameter set to the pion-mass dependence of the nucleon and omega masses as computed by the BMW Collaboration and predict the pion-mass dependence of the remaining baryon octet and decuplet states. The current lattice simulations can be described accurately and smoothly up to pion masses of about 600 MeV. In particular, we recover the recent results of the HSC without any further adjustments.

  12. Top quark mass measurements

    SciTech Connect

    L. Cerrito

    2004-07-16

    Preliminary results on the measurement of the top quark mass at the Tevatron Collider are presented. In the dilepton decay channel, the CDF Collaboration measures m{sub t} = 175.0{sub -16.9}{sup +17.4}(stat.){+-}8.4(syst.) GeV/c{sup 2}, using a sample of {approx} 126 pb{sup -1} of proton-antiproton collision data at {radical}s = 1.96 TeV (Run II). In the lepton plus jets channel, the CDF Collaboration measures 177.5{sub -9.4}{sup +12.7}(stat.) {+-} 7.1(syst.) GeV/c{sup 2}, using a sample of {approx} 102 pb{sup -1} at {radical}s = 1.96 TeV. The D0 Collaboration has newly applied a likelihood technique to improve the analysis of {approx} 125 pb{sup -1} of proton-antiproton collisions at {radical}s = 1.8 TeV (Run I), with the result: m{sub t} = 180.1 {+-} 3.6(stat.) {+-}3.9(syst.) GeV/c{sup 2}. The latter is combined with all the measurements based on the data collected in Run I to yield the most recent and comprehensive experimental determination of the top quark mass: m{sub t} = 178.0 {+-} 2.7(stat.) {+-} 3.3(syst.) GeV/c{sup 2}.

  13. f{sub 0}(600),{kappa}(800), {rho}(770) and K*(892), quark mass dependence from unitarized SU(3) Chiral Perturbation Theory

    SciTech Connect

    Nebreda, J.; Pelaez, J. R.

    2010-08-05

    We study the strange and non-strange quark mass dependence of the parameters of the f{sub 0}(600),{kappa}(800), {rho}(770) and K*(892) resonances generated from elastic meson-meson scattering using unitarized one-loop Chiral Perturbation Theory. We fit simultaneously all experimental scattering data up to 0.8-1 GeV together with lattice results on decay constants and scattering lengths up to a pion mass of 440 MeV. Then, the strange and non-strange quark masses are varied from the chiral limit up to values of interest for lattice studies. In these amplitudes, the mass and width of the {rho}(770) and K*(892) present a similar and smooth quark mass dependence. In contrast, both scalars present a similar non-analyticity at high quark masses. Nevertheless the f{sub 0}(600) dependence on both quark masses is stronger than for the {kappa}(800) and the vectors. We also confirm the lattice assumption of quark mass independence of the vector two-meson coupling that, in contrast, is violated for scalars.

  14. Quark ACM with topologically generated gluon mass

    NASA Astrophysics Data System (ADS)

    Choudhury, Ishita Dutta; Lahiri, Amitabha

    2016-03-01

    We investigate the effect of a small, gauge-invariant mass of the gluon on the anomalous chromomagnetic moment (ACM) of quarks by perturbative calculations at one-loop level. The mass of the gluon is taken to have been generated via a topological mass generation mechanism, in which the gluon acquires a mass through its interaction with an antisymmetric tensor field Bμν. For a small gluon mass ( < 10 MeV), we calculate the ACM at momentum transfer q2 = -M Z2. We compare those with the ACM calculated for the gluon mass arising from a Proca mass term. We find that the ACM of up, down, strange and charm quarks vary significantly with the gluon mass, while the ACM of top and bottom quarks show negligible gluon mass dependence. The mechanism of gluon mass generation is most important for the strange quarks ACM, but not so much for the other quarks. We also show the results at q2 = -m t2. We find that the dependence on gluon mass at q2 = -m t2 is much less than at q2 = -M Z2 for all quarks.

  15. Quark mass effect on axial charge dynamics

    NASA Astrophysics Data System (ADS)

    Guo, Er-dong; Lin, Shu

    2016-05-01

    We studied the effect of finite quark mass on the dynamics of the axial charge using the D3/D7 model in holography. The mass term in the axial anomaly equation affects both the fluctuation (generation) and dissipation of the axial charge. We studied the dependence of the effect on quark mass and an external magnetic field. For axial charge generation, we calculated the mass diffusion rate, which characterizes the helicity flipping rate. The rate is a nonmonotonous function of mass and can be significantly enhanced by the magnetic field. The diffusive behavior is also related to a divergent susceptibility of the axial charge. For axial charge dissipation, we found that in the long time limit, the mass term dissipates all the charge effectively generated by parallel electric and magnetic fields. The result is consistent with a relaxation time approximation. The rate of dissipation through mass term is a monotonous increasing function of both quark mass and a magnetic field.

  16. Prediction of new Quarks, Generations and Quark Masses

    NASA Astrophysics Data System (ADS)

    Lach, Thedore

    2002-04-01

    The Standard model currently suggests no relationship between the quark and lepton masses. The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an up quark mass of 237.31 MeV/c2 and a dn quark mass of 42.392 MeV/c2. These two new quarks help explain the numerical relationship between all the quark and lepton masses in a single function. The mass of each SNU-P (quark or lepton) is just the geometric mean of two related SNU-Ps, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.743828 (predicted), 117.3520, 1778.38, 26950.08 MeV. The resulting slope of these masses when plotted on semi log paper is "e" to 5 significant figures using the currently accepted mass for Tau. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these quarks, and lepton.

  17. Evidence for a Mass Dependent Forward-Backward Asymmetry in Top Quark Pair Production

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2011-01-01

    We present a new measurement of the inclusive forward-backward t{bar t} production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of 5.3 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the t{bar t} rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and {bar t}. In the t{bar t} rest frame, the asymmetry is observed to increase with the t{bar t} rapidity difference, {Delta}y, and with the invariant mass M{sub t{bar t}} of the t{bar t} system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large {Delta}y and M{sub t{bar t}}. For M{sub t{bar t}} {ge} 450 GeV/c{sup 2}, the parton-level asymmetry in the t{bar t} rest frame is A{sup t{bar t}} = 0.475 {+-} 0.114 compared to a next-to-leading order QCD prediction of 0.088 {+-} 0.013.

  18. Top quark mass and kinematics

    SciTech Connect

    Barberis, Emanuela; /Northeastern U.

    2006-05-01

    A summary of the results on the measurement of the Top Quark mass and the study of the kinematics of the t{bar t} system at the Tevatron collider is presented here. Results from both the CDF and D0 collaborations are reported.

  19. Prediction of new Quarks, Generations & low Mass Quarks

    NASA Astrophysics Data System (ADS)

    Lach, Theodore

    2003-04-01

    The CBM (model) of the nucleus has resulted in the prediction of two new quarks, an "up" quark of mass 237.31 MeV/c2 and a "dn" quark of mass 42.392 MeV/c2. These two new predicted quarks helped to determine that the masses of the quarks and leptons are all related by a geometric progression relationship. The mass of each quark or lepton is just the "geometric mean" of two related elementary particles, either in the same generation or in the same family. This numerology predicts the following masses for the electron family: 0.511000 (electron), 7.74 (predicted), 117.3, 1778.4 (tau), 26950.1 MeV. The geometric ratio of this progression is 15.154 (e to the power e). The mass of the tau in this theory agrees very well with accepted values. This theory suggests that all the "dn like" quarks have a mass of just 10X multiples of 4.24 MeV (the mass of the "d" quark). The first 3 "up like" quark masses are 38, 237.31 and 1500 MeV. This theory also predicts a new heavy generation with a lepton mass of 27 GeV, a "dn like" quark of 42.4 GeV, and an "up like" quark of 65 GeV. Significant evidence already exists for the existence of these new quarks, and lepton. Ref. Masses of the Sub-Nuclear Particles, nucl-th/ 0008026, @ http://xxx.lanl.gov. Infinite Energy, Vol 5, issue 30.

  20. Reduction of Quark Mass Scheme Dependence in B bar -> Xs gamma at the NNLL Level

    SciTech Connect

    Asatrian, H.M.; Greub, C.; Hovhannisyan, A.; Hurth, T.; Poghosyan, V.; /Yerevan Phys. Inst.

    2005-06-20

    The uncertainty of the theoretical prediction of the B {yields} X{sub s}{gamma} branching ratio at NLL level is dominated by the charm mass renormalization scheme ambiguity. In this paper we calculate those NNLL terms which are related to the renormalization of m{sub c}, in order to get an estimate of the corresponding uncertainty at the NNLL level. We find that these terms significantly reduce (by typically a factor of two) the error on BR(B {yields} X{sub s}{gamma}) induced by the definition of m{sub c}. Taking into account the experimental accuracy of around 10% and the future prospects of the B factories, we conclude that a NNLL calculation would increase the sensitivity of the observable B {yields} X{sub s}{gamma} to possible new degrees of freedom beyond the SM significantly.

  1. Quark masses and their hierarchies

    NASA Astrophysics Data System (ADS)

    Ida, M.

    1987-12-01

    Electroweak symmetry breaking is attributed to dynamical generation of quark masses. Quarks q (and leptons l) are assumed to be produced by hypercolor confinement of preons at an intermediate scale Λ hc. Hierarchies observed in the q mass spectra can be explained by a BCS mechanism if the color interaction is enough asymptotically free and if residual ones emerging by the confinement are medium strong. The former assumption claims that N≦4, where N is the family number of q and l. Dynamical equations to determine q masses and mixings are given, but they require knowledge on the physics at Λ hc. A phenomenological approach is also made on the basis of an SU(7)× SU(7) chiral preon model with N=4. The mass ratio m t/ mb is related to ( m c/ m s)ηB with η B≃1.1 and m t'/ mb' to ( m u/ m d)ηA with η A≃1.4. In this scheme the fourth down quark is the heaviest (˜ 110 GeV) and contributes dominantly to F 2, where F is the Fermi scale.

  2. On the flavour dependence of the O(αs4) correction to the relation between running and pole heavy quark masses

    NASA Astrophysics Data System (ADS)

    Kataev, A. L.; Molokoedov, V. S.

    2016-08-01

    Recently the four-loop perturbative QCD contributions to the relations between pole and running masses of charm, bottom and top quarks were evaluated in the overline{MS} scheme with identical numerical error bars. In this work the flavour dependence of the O(αs4) correction to these asymptotic series is obtained in the semi-analytical form with the help of the least squares method. The numerical structure of the corresponding asymptotic perturbative relations between pole and running c -, b - and t -quark masses is considered and the theoretical errors of the O(αs4) contributions are discussed. The explicit dependence for these relations on the renormalization scale μ2 and the flavour number nl is presented.

  3. QCD phase transition with chiral quarks and physical quark masses.

    PubMed

    Bhattacharya, Tanmoy; Buchoff, Michael I; Christ, Norman H; Ding, H-T; Gupta, Rajan; Jung, Chulwoo; Karsch, F; Lin, Zhongjie; Mawhinney, R D; McGlynn, Greg; Mukherjee, Swagato; Murphy, David; Petreczky, P; Renfrew, Dwight; Schroeder, Chris; Soltz, R A; Vranas, P M; Yin, Hantao

    2014-08-22

    We report on the first lattice calculation of the QCD phase transition using chiral fermions with physical quark masses. This calculation uses 2+1 quark flavors, spatial volumes between (4 fm)(3) and (11 fm)(3) and temperatures between 139 and 196 MeV. Each temperature is calculated at a single lattice spacing corresponding to a temporal Euclidean extent of N(t) = 8. The disconnected chiral susceptibility, χ(disc) shows a pronounced peak whose position and height depend sensitively on the quark mass. We find no metastability near the peak and a peak height which does not change when a 5 fm spatial extent is increased to 10 fm. Each result is strong evidence that the QCD "phase transition" is not first order but a continuous crossover for m(π) = 135 MeV. The peak location determines a pseudocritical temperature T(c) = 155(1)(8) MeV, in agreement with earlier staggered fermion results. However, the peak height is 50% greater than that suggested by previous staggered results. Chiral SU(2)(L) × SU(2)(R) symmetry is fully restored above 164 MeV, but anomalous U(1)(A) symmetry breaking is nonzero above T(c) and vanishes as T is increased to 196 MeV. PMID:25192088

  4. Top quark mass measurements at CDF

    SciTech Connect

    Maki, Tuula; /Helsinki U. /Helsinki Inst. of Phys.

    2007-10-01

    The top quark mass is interesting both as a fundamental parameter of the standard model as well as an important input to precision electroweak tests. The CDF Collaboration has measured the top quark mass with high precision in all decay channels with complementary methods. A combination of the results from CDF gives a top quark mass of 170.5{+-}1.3(stat.){+-}1.8(syst.) GeV/c{sup 2}.

  5. Quark and lepton mass matrices described by charged lepton masses

    NASA Astrophysics Data System (ADS)

    Koide, Yoshio; Nishiura, Hiroyuki

    2016-06-01

    Recently, we proposed a unified mass matrix model for quarks and leptons, in which, mass ratios and mixings of the quarks and neutrinos are described by using only the observed charged lepton mass values as family-number-dependent parameters and only six family-number-independent free parameters. In spite of quite few parameters, the model gives remarkable agreement with observed data (i.e. Cabibbo-Kobayashi-Maskawa (CKM) mixing, Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing and mass ratios). Taking this phenomenological success seriously, we give a formulation of the so-called Yukawaon model in detail from a theoretical aspect, especially for the construction of superpotentials and R charge assignments of fields. The model is considerably modified from the previous one, while the phenomenological success is kept unchanged.

  6. Debye mass and heavy quark potential in a PNJL quark plasma

    SciTech Connect

    Jankowski, J. Blaschke, D.

    2012-07-15

    We calculate the Debye mass for the screening of the heavy quark potential in a plasma of massless quarks coupled to the temporal gluon background governed by the Polyakov loop potential within the PNJL model in RPA approximation. We give a physical motivation for a recent phenomenological fit of lattice data by applying the calculated Debye mass with its suppression in the confined phase due to the Polyakov loop to a description of the temperature dependence of the singlet free energy for QCD with a heavy quark pair at infinite separation. We compare the result to lattice data.

  7. Occam's razor in quark mass matrices

    NASA Astrophysics Data System (ADS)

    Tanimoto, Morimitsu; Yanagida, Tsutomu T.

    2016-04-01

    From the standpoint of the Occam's razor approach, we consider the minimum number of parameters in the quark mass matrices needed for successful CKM mixing and CP violation. We impose three zeros in the down-quark mass matrix while taking the diagonal up-quark mass matrix to reduce the number of free parameters. The three zeros are maximal zeros in order to have a CP-violating phase in the quark mass matrix. Then, there remain six real parameters and one CP-violating phase, which is the minimal number needed to reproduce the observed data of the down-quark masses and the CKM parameters. Twenty textures with three zeros are examined. Among these, thirteen textures are viable for the down-quark mass matrix. As a representative of these textures, we discuss a texture Md^{(1)} in detail. By using the experimental data on sin 2β , θ _{13}, and θ _{23}, together with the observed quark masses, the Cabibbo angle is predicted to be close to the experimental data. It is found that this surprising result remains unchanged in all other viable textures. We also investigate the correlations between |V_{ub}/V_{cb}|, sin 2β , and J_CP. For all textures, the maximal value of the ratio |V_{ub}/V_{cb}| is 0.09, which is smaller than the upper bound of the experimental data, 0.094. We hope that this prediction will be tested in future experiments.

  8. Renormalization of the quark mass matrix

    NASA Astrophysics Data System (ADS)

    Chiu, S. H.; Kuo, T. K.

    2016-05-01

    Using a set of rephasing-invariant variables, it is shown that the renormalization group equations for quark mixing parameters can be written in a form that is compact, in addition to having simple properties under flavor permutation. We also found approximate solutions to these equations if the quark masses are hierarchical or nearly degenerate.

  9. Properties of color-flavor locked strange quark matter and strange stars in a new quark mass scaling

    NASA Astrophysics Data System (ADS)

    Chang, Qian; Chen, ShiWu; Peng, GuangXiong; Xu, JianFeng

    2013-09-01

    Considering the effect of one-gluon-exchange interaction between quarks, the color-flavor locked strange quark matter and strange stars are investigated in a new quark mass density-dependent model. It is found that the color-flavor locked strange quark matter can be more stable if the one-gluon-exchange effect is included. The lower density behavior of the sound velocity in this model is different from the previous results. Moreover, the new equation of state leads to a heavier acceptable maximum mass, supporting the recent observation of a compact star mass as large as about 2 times the solar mass.

  10. Azimuthal dependence of the heavy quark initiated contributions to DIS

    SciTech Connect

    Ananikyan, L. N.; Ivanov, N. Ya.

    2007-01-01

    We analyze the azimuthal dependence of the heavy-quark-initiated contributions to the lepton-nucleon deep inelastic scattering (DIS). First we derive the relations between the parton-level semi-inclusive structure functions and the helicity {gamma}*Q cross sections in the case of arbitrary values of the heavy quark mass. Then the azimuth-dependent O({alpha}{sub s}) lepton-quark DIS is calculated in the helicity basis. Finally, we investigate numerically the properties of the cos{phi} and cos2{phi} distributions caused by the photon-quark scattering (QS) contribution. It turns out that, contrary to the basic photon-gluon fusion (GF) component, the QS mechanism is practically cos2{phi}-independent. This fact implies that measurements of the azimuthal distributions in charm leptoproduction could directly probe the charm density in the proton.

  11. Heavy quark masses from lattice QCD

    NASA Astrophysics Data System (ADS)

    Lytle, Andrew T.

    2016-07-01

    Progress in quark mass determinations from lattice QCD is reviewed, focusing on results for charm and bottom mass. These are of particular interest for precision Higgs studies. Recent determinations have achieved percent-level uncertainties with controlled systematics. Future prospects for these calculations are also discussed.

  12. Top quark mass measurements at CDF

    SciTech Connect

    Brubaker, Erik; /Chicago U., EFI

    2006-05-01

    The mass of the top quark M{sub top} is interesting both as a fundamental parameter of the standard model and as an important input to precision electroweak tests. The Collider Detector at Fermilab (CDF) has a robust program of top quark mass analyses, including the most precise single measurement, M{sub top} = 173.4 {+-} 2.8 GeV/c{sup 2}, using 680 pb{sup -1} of p{bar p} collision data. A combination of current results from CDF gives M{sub top} = 172.0 {+-} 2.7 GeV/c{sup 2}, surpassing the stated goal of 3 GeV/c{sup 2} precision using 2 fb{sup -1} of data. Finally, a combination with current D0 results gives a world average top quark mass of 172.5 {+-} 2.3 GeV/c{sup 2}.

  13. Measurement of the Top Quark Mass

    SciTech Connect

    Blair, R.E.; Byrum, K.L.; Kovacs, E.; Kuhlmann, S.E.; LeCompte, T.; Nodulman, L.; Breccia, L.; Brunetti, R.; Deninno, M.; Fiori, I.; Mazzanti, P.; Behrends, S.; Bensinger, J.; Blocker, C.; Kirsch, L.; Lamoureux, J.I.; Bonushkin, Y.; Hauser, J.; Lindgren, M.; Amadon, A.; Berryhill, J.; Contreras, M.; Culbertson, R.; Frisch, H.; Grosso-Pilcher, C.; Hohlmann, M.; Cronin-Hennessy, D.; Dittmann, J.R.; Goshaw, A.T.; Khazins, D.; Kowald, W.; Oh, S.H.; Albrow, M.G.; Atac, M.; Beretvas, A.; Berge, J.P.; Biery, K.; Binkley, M.; Buckley-Geer, E.; Byon-Wagner, A.; Chlebana, F.; Cihangir, S.; Cooper, J.; DeJongh, F.; Demina, R.; Derwent, P.F.; Elias, J.E.; Erdmann, W.; Flaugher, B.; Foster, G.W.; Freeman, J.; Geer, S.; Hahn, S.R.; Harris, R.M.; Incandela, J.; Jensen, H.; Joshi, U.; Kennedy, R.D.; Kephart, R.; Lammel, S.; Lewis, J.D.; Limon, P.; Lukens, P.; Maeshima, K.; Marriner, J.P.; Miao, T.; Mukherjee, A.; Nelson, C.; Newman-Holmes, C.; Patrick, J.; Klimenko, S.; Konigsberg, J.; Korytov, A.; Nomerotski, A.; Barone, M.; Bertolucci, S.; Cordelli, M.; DellAgnello, S.; Giromini, P.; Happacher, F.; Miscetti, S.; Parri, A.; Clark, A.G.; Couyoumtzelis, C.; Kambara, H.; Baumann, T.; Franklin, M.; Gordon, A.; Hamilton, R.; Huth, J.; and others

    1998-03-01

    We present a measurement of the top quark mass using a sample of t{bar t} decays into an electron or a muon, a neutrino, and four jets. The data were collected in p{bar p} collisions at {radical}(s)=1.8 TeV with the Collider Detector at Fermilab and correspond to an integrated luminosity of 109 pb{sup {minus}1} . We measure the top quark mass to be 175.9{plus_minus}4.8(stat){plus_minus}4.9( syst) GeV /c{sup 2} . {copyright} {ital 1998} {ital The American Physical Society}

  14. Precision Determination of the Top Quark Mass

    SciTech Connect

    Movilla Fernandez, Pedro A.; /LBL, Berkeley

    2007-05-01

    The CDF and D0 collaborations have updated their measurements of the mass of the top quark using proton-antiproton collisions at {radical}s = 1.96 TeV produced at the Tevatron. The uncertainties in each of the top-antitop decay channels have been reduced. The new Tevatron average for the mass of the top quark based on about 1 fb{sup -1} of data per experiment is 170.9 {+-} 1.8 GeV/c{sup 2}.

  15. Variations of nuclear binding with quark masses

    NASA Astrophysics Data System (ADS)

    Carrillo-Serrano, M. E.; Cloët, I. C.; Tsushima, K.; Thomas, A. W.; Afnan, I. R.

    2013-01-01

    We investigate the variation with light quark mass of the mass of the nucleon as well as the masses of the mesons commonly used in a one-boson-exchange model of the nucleon-nucleon force. Care is taken to evaluate the meson mass shifts at the kinematic point relevant to that problem. Using these results, we evaluate the corresponding changes in the energy of the 1S0 antibound state and the binding energies of the deuteron, triton, and selected finite nuclei by using a one-boson exchange model. The results are discussed in the context of possible corrections to the standard scenario for Big Bang nucleosynthesis in the case where, as suggested by recent observations of quasar absorption spectra, the quark masses may have changed over the age of the Universe.

  16. Quark masses and the meson spectrum: A holographic approach

    NASA Astrophysics Data System (ADS)

    Afonin, S. S.; Pusenkov, I. V.

    2015-09-01

    Based on experimental data, we can assume that the radial spectrum of vector mesons with a hidden quark flavor has a Regge form and propose its concrete form. The parameters of the Regge spectrum turn out to depend strongly on the mass of the quarks forming the mesons. We consider the problem of finding the form of these dependences in the framework of the holographic approach to strong interactions. The obtained results agree well with the phenomenology and with models of Veneziano-like dual amplitudes.

  17. World average top-quark mass

    SciTech Connect

    Glenzinski, D.; /Fermilab

    2008-01-01

    This paper summarizes a talk given at the Top2008 Workshop at La Biodola, Isola d Elba, Italy. The status of the world average top-quark mass is discussed. Some comments about the challanges facing the experiments in order to further improve the precision are offered.

  18. QUARK ANTIQUARK ENERGIES AND THE SCREENING MASS IN A QUARK-GLUON PLASMA AT LOW AND HIGH TEMPERATURES.

    SciTech Connect

    ZANTOW, F.; KACZMAREK, O.

    2005-08-02

    We discuss quark antiquark energies and the screening mass in hot QCD using the non-perturbative lattice approach. For this purpose we analyze properties of quark antiquark energies and entropies at infinitely large separation of the quark antiquark pair at low and high temperatures. In the limit of high temperatures these energies and entropies can be related perturbatively to the temperature dependence of the Debye mass and the coupling. On the one hand our analysis thus suggests that the quark antiquark energies at (infinite) large distances are rather related to the Debye screening mass and the coupling than to the temperature dependence of heavy-light meson masses. On the other hand we find no or only little differences in all mass scales introduced by us when changing from quenched to 2-flavor QCD at temperatures which are only moderately above the phase transition.

  19. D{O} top quark mass analysis

    SciTech Connect

    Strovink, M.

    1995-07-01

    Based on (44-48 pb{sup -1}) of lepton + jets data, we review D0`s initial analysis of the top quark mass. The result, M{sub top} = 199 {+-} 19/21 (stat.) {+-} 22 (syst.) GeV/c{sup 2}, is insensitive to background normalization. The errors are based on ISAJET top Monte Carlo, with its more severe gluon radiation, and allow for ISAJET/HERWIG differences. Good progress is being made in reducing the systematic error. We present a new study based on two-dimensional distributions of reconstructed top quark vs. dijet mass. With 98.7% confidence we observe a peak in the top mass - dijet mass plane. The peak and its projections are similar both in shape and magnitude to expectations based on the decay sequence 1 {yields} bW, W {yields} jj.

  20. Domain wall QCD with physical quark masses

    NASA Astrophysics Data System (ADS)

    Blum, T.; Boyle, P. A.; Christ, N. H.; Frison, J.; Garron, N.; Hudspith, R. J.; Izubuchi, T.; Janowski, T.; Jung, C.; Jüttner, A.; Kelly, C.; Kenway, R. D.; Lehner, C.; Marinkovic, M.; Mawhinney, R. D.; McGlynn, G.; Murphy, D. J.; Ohta, S.; Portelli, A.; Sachrajda, C. T.; Soni, A.; Rbc; Ukqcd Collaborations

    2016-04-01

    We present results for several light hadronic quantities (fπ , fK, BK, mu d, ms, t01 /2, w0) obtained from simulations of 2 +1 flavor domain wall lattice QCD with large physical volumes and nearly physical pion masses at two lattice spacings. We perform a short, O (3 )%, extrapolation in pion mass to the physical values by combining our new data in a simultaneous chiral/continuum "global fit" with a number of other ensembles with heavier pion masses. We use the physical values of mπ, mK and mΩ to determine the two quark masses and the scale—all other quantities are outputs from our simulations. We obtain results with subpercent statistical errors and negligible chiral and finite-volume systematics for these light hadronic quantities, including fπ=130.2 (9 ) MeV ; fK=155.5 (8 ) MeV ; the average up/down quark mass and strange quark mass in the MS ¯ scheme at 3 GeV, 2.997(49) and 81.64(1.17) MeV respectively; and the neutral kaon mixing parameter, BK, in the renormalization group invariant scheme, 0.750(15) and the MS ¯ scheme at 3 GeV, 0.530(11).

  1. Top quark mass measurement at the Tevatron

    SciTech Connect

    Guimaraes da Costa, Joao; /Harvard U.

    2004-12-01

    The authors report on the latest experimental measurements of the top quark mass by the CDF and D0 Collaborations at the Fermilab Tevatron. They present a new top mass measurement using the t{bar t} events collected by the D0 Collaboration in Run I between 1994 and 1996. This result is combined with previous measurements to yield a new world top mass average. They also describe several preliminary results using up to 193 pb{sup -1} of t{bar t} events produced in {bar p}p collisions at {radical}s = 1.96 TeV during the Run II of the Tevatron.

  2. Quark flavor mixings from hierarchical mass matrices

    NASA Astrophysics Data System (ADS)

    Verma, Rohit; Zhou, Shun

    2016-05-01

    In this paper, we extend the Fritzsch ansatz of quark mass matrices while retaining their hierarchical structures and show that the main features of the Cabibbo-Kobayashi-Maskawa (CKM) matrix V, including |V^{}_{us}| ˜eq |V^{}_{cd}|, |V^{}_{cb}| ˜eq |V^{}_{ts}| and |V^{}_{ub}|/|V^{}_{cb}| < |V^{}_{td}|/|V^{}_{ts}|, can be well understood. This agreement is observed especially when the mass matrices have non-vanishing (1, 3) and (3, 1) off-diagonal elements. The phenomenological consequences of these for the allowed texture content and gross structural features of `hierarchical' quark mass matrices are addressed from a model-independent prospective under the assumption of factorizable phases in these. The approximate and analytical expressions of the CKM matrix elements are derived and a detailed analysis reveals that such structures are in good agreement with the observed quark flavor mixing angles and the CP-violating phase at the 1σ level and call upon a further investigation of the realization of these structures from a top-down prospective.

  3. Bottom quark mass from {Upsilon} mesons

    SciTech Connect

    Hoang, A.H.

    1999-01-01

    The bottom quark pole mass M{sub b} is determined using a sum rule which relates the masses and the electronic decay widths of the {Upsilon} mesons to large {ital n} moments of the vacuum polarization function calculated from nonrelativistic quantum chromodynamics. The complete set of next-to-next-to-leading order [i.e., O({alpha}{sub s}{sup 2},{alpha}{sub s}v,v{sup 2}) where v is the bottom quark c.m. velocity] corrections is calculated and leads to a considerable reduction of theoretical uncertainties compared to a pure next-to-leading order analysis. However, the theoretical uncertainties remain much larger than the experimental ones. For a two parameter fit for M{sub b}, and the strong M{bar S} coupling {alpha}{sub s}, and using the scanning method to estimate theoretical uncertainties, the next-to-next-to-leading order analysis yields 4.74 GeV {le}M{sub b}{le}4.87 GeV and 0.096{le}{alpha}{sub s}(M{sub z}){le}0.124 if experimental uncertainties are included at the 95{percent} confidence level and if two-loop running for {alpha}{sub s} is employed. M{sub b} and {alpha}{sub s} have a sizable positive correlation. For the running M{bar S} bottom quark mass this leads to 4.09 GeV {le}m{sub b}(M{sub {Upsilon}(1S)}/2){le}4.32 GeV. If {alpha}{sub s} is taken as an input, the result for the bottom quark pole mass reads 4.78 GeV {le}M{sub b}{le}4.98 GeVthinsp[4.08 GeV {le}m{sub b}(M{sub {Upsilon}(1S)}/2){le}4.28 GeV] for 0.114{le}{alpha}{sub s}(M{sub z}){le}0.122. The discrepancies between the results of three previous analyses on the same subject by Voloshin, Jamin, and Pich and K{umlt u}hn {ital et al.} are clarified. A comprehensive review on the calculation of the heavy-quark{endash}antiquark pair production cross section through a vector current at next-to-next-to leading order in the nonrelativistic expansion is presented. {copyright} {ital 1998} {ital The American Physical Society}

  4. Dynamical generation of the top quark mass

    NASA Astrophysics Data System (ADS)

    Popovic, Marko Berislav

    2002-09-01

    I study new physics theories in which the observed mass of the heaviest elementary particle, the top quark, is a result of a dynamical mechanism at the subatomic level. The same mechanism needs to explain the transition of the effective physical description at the largest space-time scales to that at smaller scales. This large-scale description is characterized by non-zero masses for most of the elementary particles and the existence of the familiar electromagnetic interactions. The description at smaller space-time scales is characterized by the presence of a richer set of fundamental interactions, including weak and hypercharge interactions, as well as no masses for the particles. As a minimal consequence of this transition, particle theories commonly predict the existence of a still unobserved particle, called the Higgs, at the largest scales. New physics considered in this thesis includes the following: (1) Models with new fundamental interactions that select the top quark and give an exclusive role to its dynamical mass generation mechanism. I propose one such model, discuss current experimental constraints, and suggest future tests of this idea. (2) Models with new spin one-half particles, not sensitive to the weak interactions, that mix with ordinary particles, including the top quark. I discuss the phenomenology, i.e., analyze data from particle colliders, and set limits on the parameters of the models. (3) Models with new spin one-half particles, sensitive to the weak interactions, that mix with ordinary particles. I propose the model structure, discuss some of its phenomenology, and suggest further tests of this idea at linear particle accelerators. Finally, I analyze the connection between the Higgs mass (m H) and the space-time scale at which the above-mentioned transition occurs. Without introducing new physics at the smallest scales, I show that due to the very large top mass, the standard description with the Higgs particle fails at small scales

  5. Quark masses, the Dashen phase, and gauge field topology

    SciTech Connect

    Creutz, Michael

    2013-12-15

    The CP violating Dashen phase in QCD is predicted by chiral perturbation theory to occur when the up–down quark mass difference becomes sufficiently large at fixed down-quark mass. Before reaching this phase, all physical hadronic masses and scattering amplitudes are expected to behave smoothly with the up-quark mass, even as this mass passes through zero. In Euclidean space, the topological susceptibility of the gauge fields is positive at positive quark masses but diverges to negative infinity as the Dashen phase is approached. A zero in this susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. I discuss potential ambiguities with this determination. -- Highlights: •The CP violating Dashen phase in QCD occurs when the up quark mass becomes sufficiently negative. •Before reaching this phase, all physical hadronic masses and scattering amplitudes behave smoothly with the up-quark mass. •The topological susceptibility of the gauge fields diverges to negative infinity as the Dashen phase is approached. •A zero in the topological susceptibility provides a tentative signal for the point where the mass of the up quark vanishes. •The universality of this definition remains unproven. Potential ambiguities are discussed.

  6. Dynamics Behind the Quark Mass Hierarchy and Electroweak Symmetry breaking

    NASA Astrophysics Data System (ADS)

    Miransky, Vladimir A.

    2011-05-01

    I review the dynamics in a new class of models describing the quark mass hierarchy, suggested recently by Michio Hashimoto and the author. In this class, the dynamics primarily responsible for electroweak symmetry breaking (EWSB) leads to the mass spectrum of quarks with no (or weak) isospin violation. Moreover, the values of these masses are of the order of the observed masses of the down-type quarks. Then, strong (although subcritical) horizontal diagonal interactions for the t quark plus horizontal flavor-changing neutral interactions between different families lead (with no fine tuning) to a realistic quark mass spectrum. In this scenario, many composite Higgs bosons occur. A concrete model with the dynamical EWSB with the fourth family is described in detail.

  7. Dynamics Behind the Quark Mass Hierarchy and Electroweak Symmetry breaking

    SciTech Connect

    Miransky, Vladimir A.

    2011-05-24

    I review the dynamics in a new class of models describing the quark mass hierarchy, suggested recently by Michio Hashimoto and the author. In this class, the dynamics primarily responsible for electroweak symmetry breaking (EWSB) leads to the mass spectrum of quarks with no (or weak) isospin violation. Moreover, the values of these masses are of the order of the observed masses of the down-type quarks. Then, strong (although subcritical) horizontal diagonal interactions for the t quark plus horizontal flavor-changing neutral interactions between different families lead (with no fine tuning) to a realistic quark mass spectrum. In this scenario, many composite Higgs bosons occur. A concrete model with the dynamical EWSB with the fourth family is described in detail.

  8. Threshold corrections to the bottom quark mass revisited

    NASA Astrophysics Data System (ADS)

    Anandakrishnan, Archana; Bryant, B. Charles; Raby, Stuart

    2015-05-01

    Threshold corrections to the bottom quark mass are often estimated under the approximation that tan β enhanced contributions are the most dominant. In this work we revisit this common approximation made to the estimation of the supersymmetric thresh-old corrections to the bottom quark mass. We calculate the full one-loop supersymmetric corrections to the bottom quark mass and survey a large part of the phenomenological MSSM parameter space to study the validity of considering only the tan β enhanced corrections. Our analysis demonstrates that this approximation underestimates the size of the threshold corrections by ˜ 12.5% for most of the considered parameter space. We discuss the consequences for fitting the bottom quark mass and for the effective couplings to Higgses. We find that it is important to consider the additional contributions when fitting the bottom quark mass but the modifications to the effective Higgs couplings are typically (few)% for the majority of the parameter space considered.

  9. Measurement of the top quark mass at D0

    SciTech Connect

    Protopopescu, S.; D0 Collaboration

    1996-12-31

    The mass of the top quark is measured using a sample of 93 lepton + 4 or more jets events collected with the D0 detector at the FNAL Tevatron collider. The authors find the top quark mass is 169 {+-} 8(stat.) {+-} 8(syst.) GeV/c{sup 2}. The analysis assumes that top quarks are produced as t{anti t} pairs that decay to W bosons and b quarks. The final states result when one W decays to e{nu} or {mu}{nu} and the other W to q{anti q}. More than four jets may be present because of final and initial state radiation.

  10. Infrared Renormalization-Group Flow for Heavy-Quark Masses

    SciTech Connect

    Hoang, Andre H.; Jain, Ambar; Stewart, Iain W.; Scimemi, Ignazio

    2008-10-10

    A short-distance heavy-quark mass depends on two parameters: the renormalization scale {mu} and a scale R controlling the absorption of infrared fluctuations. The radius for perturbative corrections that build up the mass beyond its pointlike definition in the pole scheme is {approx}1/R. Treating R as a variable gives a renormalization-group equation. R evolution improves the stability of conversion between short-distance mass schemes, allowing us to avoid large logs and the renormalon. R evolution can also be used to study IR renormalons without using bubble chains, yielding a convergent sum rule for the coefficient of the O({lambda}{sub QCD}) renormalon ambiguity of the pole mass.

  11. Quark-jet model for transverse momentum dependent fragmentation functions

    NASA Astrophysics Data System (ADS)

    Bentz, W.; Kotzinian, A.; Matevosyan, H. H.; Ninomiya, Y.; Thomas, A. W.; Yazaki, K.

    2016-08-01

    In order to describe the hadronization of polarized quarks, we discuss an extension of the quark-jet model to transverse momentum dependent fragmentation functions. The description is based on a product ansatz, where each factor in the product represents one of the transverse momentum dependent splitting functions, which can be calculated by using effective quark theories. The resulting integral equations and sum rules are discussed in detail for the case of inclusive pion production. In particular, we demonstrate that the three-dimensional momentum sum rules are satisfied naturally in this transverse momentum dependent quark-jet model. Our results are well suited for numerical calculations in effective quark theories and can be implemented in Monte Carlo simulations of polarized quark hadronization processes.

  12. Relativistic quantum model of confinement and the current quark masses

    NASA Astrophysics Data System (ADS)

    Soloviev, L. D.

    1998-08-01

    We consider a relativistic quantum model of confined massive spinning quarks and antiquarks which describes the leading Regge trajectories of mesons. The quarks are described by the Dirac equations and the gluon contribution is approximated by the Nambu-Goto straight-line string. The string tension and the current quark masses are the main parameters of the model. Additional parameters are phenomenological constants which approximate nonstring short-range contributions. A comparison of the measured meson masses with the model predictions allows one to determine the current quark masses (in MeV) to be ms=227+/-5, mc=1440+/-10, and mb=4715+/-20. The chiral SU3 model makes it possible to estimate from here the u- and d-quark masses to be mu=6.2+/-0.2 Mev and md=11.1+/-0.4 Mev.

  13. GUT predictions for quark and lepton mass ratios

    SciTech Connect

    Antusch, S.; Spinrath, M.

    2010-02-10

    Group theoretical factors from GUT symmetry breaking can lead to predictions for the ratios of quark and lepton masses at the unification scale. Due to supersymmetric (SUSY) threshold corrections the viability of such predictions can depend strongly on the SUSY parameters. We derive possible new predictions for the GUT scale ratios m{sub m}u/m{sub s}, ytau/y{sub b} and y{sub t}/y{sub b} and compare them with the experimentally allowed ranges for three common SUSY breaking scenarios.

  14. Simple mass matrices of neutrinos and quarks consistent with observed mixings and masses

    NASA Astrophysics Data System (ADS)

    Nishiura, Hiroyuki; Fukuyama, Takeshi

    2016-02-01

    We propose a simple phenomenological model of quarks-leptons mass matrices having fundamentally universal symmetry structure. These mass matrices consist of democratic and semi-democratic mass matrix terms commonly to the neutrino and the quark sectors and have only eight free parameters. We show that this mass matrix model well reproduces all the observed values of the MNS lepton and the CKM quark mixing angles, the neutrino mass squared difference ratio, and quark mass ratios, with an excellent agreement. The model also predicts δCPℓ = - 94 ° for the leptonic CP violating phase and < m > ≃ 0.0073 eV for the effective Majorana neutrino mass.

  15. Measurement of the top quark mass

    SciTech Connect

    Varnes, E.W.

    1997-12-31

    This dissertation describes the measurement of the top quark mass m{sub t} using events recorded during a 125 pb{sup -1} exposure of the D0 detector to {radical}s=1.8 TeV {anti p}p collisions. Six events consistent with the hypothesis t{anti t} {yields} bW{sup +}, {anti b}W{sup -} {yields} b{anti l}{nu}, {anti b}l{anti {nu}} form the dilepton sample. The kinematics of such events may be reconstructed for any assumed mt, and the likelihood of each such solution evaluated. A measurement of m{sub t} based on these relative solution likelihoods gives m{sub t} = 169.9 {+-} 14.8 (stat.) {+-} 3. 8 (syst.) GeV/c{sup 2}. A 2C kinematic fit is performed on a sample of 77 events consistent with t{anti t} {yields} bW{sup +}, {anti b}W{sup -} {yields} b{anti l}{nu}, {anti b}q{anti q} , and this, in combination with an estimate on the likelihood that each event is top, yields m{sub t} = 173.3 {+-} 5.6 (stat.) {+-} 6.2 (syst.) GeV/c{sup 2} . A combination of these two measurements gives m{sub t} = 173.1 {+-} 5.2 (stat.) {+-} 5.7 (syst.) GeV/c{sup 2}.

  16. Quark mass functions and pion structure in Minkowski space

    SciTech Connect

    Biernat, Elmer P.; Gross, Franz L.; Pena, Maria Teresa; Stadler, Alfred

    2014-03-01

    We present a study of the dressed quark mass function and the pion structure in Minkowski space using the Covariant Spectator Theory (CST). The quark propagators are dressed with the same kernel that describes the interaction between different quarks. We use an interaction kernel in momentum space that is a relativistic generalization of the linear confining q-qbar potential and a constant potential shift that defines the energy scale. The confining interaction has a Lorentz scalar part that is not chirally invariant by itself but decouples from the equations in the chiral limit and therefore allows the Nambu--Jona-Lasinio (NJL) mechanism to work. We adjust the parameters of our quark mass function calculated in Minkowski-space to agree with LQCD data obtained in Euclidean space. Results of a calculation of the pion electromagnetic form factor in the relativistic impulse approximation using the same mass function are presented and compared with experimental data.

  17. A Precision Measurement of the Top Quark Mass

    SciTech Connect

    Black, Kevin Matthew

    2005-05-01

    This dissertation describes the measurement of the top quark mass using events recorded during a {approx} 230 pb{sup -1} exposure of the D0 detector to proton-anti-proton (p{bar p}) collisions at a center of mass energy of 1.96 TeV. The Standard Model of particle physics predicts that the top quark will decay into a bottom quark and a W boson close to 100% of the time. The bottom quark will hadronize (bind with another quark) and produce a jet of hadronic particles. The W bosons can decay either into a charged lepton and a neutrino or a pair of quarks. this dissertation focuses on the top quark (t{bar t}) events in which one W decays hadronically and the other decays leptonically. Two methods of identifying t{bar t} events from the large number of events produced are used. The first is based on the unique topology of the final state particles of a heavy particle. By using the topological information of the event, the t{bar t} events can be efficiently extracted from the background. The second method relies on the identification of the remnants of the long lived bottom quarks that are expected to be produced in the decay of almost every top quark. Because the largest background processes do not contain bottom quarks, this is an extremely efficient way to select the events retaining about 60% of the t{bar t} events and removing almost 90% of the background. A kinematic fit to the top quark mass is performed on the t{bar t} candidate events using the final state particles that are seen in the detector. A likelihood technique is then used to extract the most likely value of the top quark mass, m{sub t}, and signal fraction. The result for the topological selection is m{sub t} = 169.9 {+-} 5.8(statistical){sub -7.8}{sup +8.0}(systematic) GeV while the results on the sample selected from identification of a b quark in the event is m{sub t} = 170.6 {+-} 4.2(statistical){sub -6.8}{sup +6.3}(systematic) GeV.

  18. Density-Dependent Relations among Properties of Hadronic Matter and Applications to Hadron-Quark Stars

    SciTech Connect

    Uechi, Hiroshi; Uechi, Schun T.

    2011-05-06

    Density-dependent relations among the saturation properties of symmetric nuclear matter and hyperonic matter, and properties of hadron-(strange) quark stars are shown by applying the conserving nonlinear {sigma}-{omega}-{rho} hadronic mean-field theory. Nonlinear interactions are renormalized self-consistently as effective coupling constants, effective masses, and sources of equations of motion by maintaining thermodynamic consistency to the mean-field approximation. Effective masses and coupling constants at the saturation point of symmetric nuclear matter simultaneously determine the binding energy and saturation properties of hyperonic matter. The coupling constants expected from the hadronic mean-field model and SU(6) quark model for the vector coupling constants are compared by calculating masses of hadron-quark neutron stars. The nonlinear {sigma}-{omega}-{rho} mean-field approximation with vacuum fluctuation corrections and strange quark matter defined by the MIT-bag model were employed to examine properties of hadron-(strange) quark stars. We found that hadron-(strange) quark stars become more stable at high densities compared to pure hadronic and strange quark stars.

  19. Top quark mass measurement using the template method at CDF

    DOE PAGESBeta

    Aaltonen, T

    2011-06-03

    We present a measurement of the top quark mass in the lepton+jets and dilepton channels of tmore » $$\\bar{t}$$ decays using the template method. The data sample corresponds to an integrated luminosity of 5.6 fb-1 of p$$\\bar{p}$$ collisions at Tevatron with √s = 1.96 TeV, collected with the CDF II detector. The measurement is performed by constructing templates of three kinematic variables in the lepton+jets and two kinematic variables in the dilepton channel. The variables are two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the W decay in the lepton+jets channel, and a reconstructed top quark mass and mT2, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of Mtop = 172.1±1.1 (stat)±0.9 (syst) GeV/c2.« less

  20. Top quark mass measurement using the template method at CDF

    SciTech Connect

    Aaltonen, T

    2011-06-03

    We present a measurement of the top quark mass in the lepton+jets and dilepton channels of t$\\bar{t}$ decays using the template method. The data sample corresponds to an integrated luminosity of 5.6 fb-1 of p$\\bar{p}$ collisions at Tevatron with √s = 1.96 TeV, collected with the CDF II detector. The measurement is performed by constructing templates of three kinematic variables in the lepton+jets and two kinematic variables in the dilepton channel. The variables are two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the W decay in the lepton+jets channel, and a reconstructed top quark mass and mT2, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of Mtop = 172.1±1.1 (stat)±0.9 (syst) GeV/c2.

  1. Sensitivity of hyperfine structure to nuclear radius and quark mass variation

    SciTech Connect

    Dinh, T. H.; Dunning, A.; Dzuba, V. A.; Flambaum, V. V.

    2009-05-15

    To search for the temporal variation in the fundamental constants, one needs to know dependence of atomic transition frequencies on these constants. We study the dependence of the hyperfine structure of atomic s levels on nuclear radius and, via radius, on quark masses. An analytical formula has been derived and tested by the numerical relativistic Hartree-Fock calculations for Rb, Cd{sup +}, Cs, Yb{sup +}, and Hg{sup +}. The results of this work allow the use of the results of past and future atomic clock experiments and quasar spectra measurements to put constraints on time variation in the quark masses.

  2. Running of the bottom quark mass within the MSSM

    SciTech Connect

    Mihaila, L.

    2008-11-23

    We compute the exact two-loop matching coefficient for the bottom-quark mass m{sub b}, within the Minimal Supersymmetric Standard Model (MSSM), taking into account O({alpha}{sub s}{sup 2}) contributions from the Supersymmetric Quantum Chromodynamics (SQCD). We find that the three-loop order corrections to the running bottom-quark mass exceed the uncertainty due to the current experimental accuracy. They can reach up to 30% from the tree-level m{sub b}, for models with large values of tan {beta} and relatively light SUSY mass scale.

  3. Hierarchy plus anarchy in quark masses and mixings

    NASA Astrophysics Data System (ADS)

    Aguilar-Saavedra, J. A.

    2003-04-01

    We introduce a parametrization of the effect of unknown corrections from new physics on quark and lepton mass matrices. This parametrization is used in order to study how the hierarchies of quark masses and mixing angles are modified by random perturbations of the Yukawa matrices. We discuss several examples of flavor relations predicted by different textures, analyzing how these relations are influenced by the random perturbations. We also comment on the unlikely possibility that unknown corrections contribute significantly to the hierarchy of masses and mixings.

  4. Off-shell {rho}-{omega} mixing through quark loops with a nonperturbative meson vertex and quark mass functions

    SciTech Connect

    Mitra, A.N.; Yang, K.

    1995-06-01

    The momentum dependence of the off-shell {rho}-{omega} mixing amplitude is calculated through a two-quark loop diagram, using nonperturbative meson-quark vertex functions for the {rho} and {omega} mesons, as well as nonperturbative quark propagators. Both these quantities are generated self-consistently through an interlinked Bethe-Salpeter equation (BSE) cum Schwinger- Dyson equation (SDE) approach with a 3D support for the BSE kernel with two basic constants that are prechecked against a wide cross section of both meson and baryon spectra within a common structural framework for their respective 3D BSE`s. With the precalibration, the on-shell strength works out at {minus}2.434 {delta}({ital m}{sub {ital q}}{sup 2}) in units of the change in ``constituent mass squared,`` which is consistent with the {ital e}{sup +}{ital e}{sup {minus}} to {pi}{sup +}{pi}{sup {minus}} data for a {ital u}-{ital d} mass difference of 4 MeV, while the relative off-shell strength (0.99{plus_minus}0.01) lies midway between quark-loop and QCD-SR results. We also calculate the photon-mediated {rho}-{omega} propagator whose off-shell structure has an additional pole at {ital q}{sup 2}=0. The implications of these results vis-a-vis related investigations are discussed.

  5. Helicity-dependent generalized parton distributions and composite constituent quarks

    SciTech Connect

    Scopetta, Sergio; Vento, Vicente

    2005-01-01

    An approach, recently proposed to calculate the nucleon generalized parton distributions (GPDs) in a constituent quark model (CQM) scenario, in which the constituent quarks are taken as complex systems, is used to obtain helicity-dependent GPDs. They are obtained from the wave functions of the nonrelativistic CQM of Isgur and Karl, convoluted with the helicity-dependent GPDs of the constituent quarks themselves. The latter are modeled by using the polarized structure functions of the constituent quark, the double distribution representation of GPDs, and a phenomenological constituent quark form factor. The present approach permits us to access a kinematical range corresponding to both the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi and the Efremov-Radyushkin-Brodsky-Lepage regions, for small values of the momentum transfer and of the skewedness parameter. In this kinematical region, the present calculation represents a prerequisite for the evaluation of cross sections relevant to deeply virtual Compton scattering. In particular, we have calculated the leading twist helicity-dependent GPD H-tilde and, from our expressions, its general relations with the nonrelativistic definition of the axial form factor and with the leading twist polarized quark density are consistently recovered.

  6. Quark matter symmetry energy and quark stars

    SciTech Connect

    Chu, Peng-Cheng; Chen, Lie-Wen

    2014-01-10

    We extend the confined-density-dependent-mass (CDDM) model to include isospin dependence of the equivalent quark mass. Within the confined-isospin-density-dependent-mass (CIDDM) model, we study the quark matter symmetry energy, the stability of strange quark matter, and the properties of quark stars. We find that including isospin dependence of the equivalent quark mass can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. While the recently discovered large mass pulsars PSR J1614–2230 and PSR J0348+0432 with masses around 2 M {sub ☉} cannot be quark stars within the CDDM model, they can be well described by quark stars in the CIDDM model. In particular, our results indicate that the two-flavor u-d quark matter symmetry energy should be at least about twice that of a free quark gas or normal quark matter within the conventional Nambu-Jona-Lasinio model in order to describe PSR J1614–2230 and PSR J0348+0432 as quark stars.

  7. Measurement of the Top Quark Mass in Dilepton Final States with the Neutrino Weighting Method

    SciTech Connect

    Ilchenko, Yuriy

    2012-12-15

    The top quark is the heaviest fundamental particle observed to date. The mass of the top quark is a free parameter in the Standard Model (SM). A precise measurement of its mass is particularly important as it sets an indirect constraint on the mass of the Higgs boson. It is also a useful constraint on contributions from physics beyond the SM and may play a fundamental role in the electroweak symmetry breaking mechanism. I present a measurement of the top quark mass in the dilepton channel using the Neutrino Weighting Method. The data sample corresponds to an integrated luminosity of 4.3 fb-1 of p$\\bar{p}$ collisions at Tevatron with √s = 1.96 TeV, collected with the DØ detector. Kinematically under-constrained dilepton events are analyzed by integrating over neutrino rapidity. Weight distributions of t$\\bar{t}$ signal and background are produced as a function of the top quark mass for different top quark mass hypotheses. The measurement is performed by constructing templates from the moments of the weight distributions and input top quark mass, followed by a subsequent likelihood t to data. The dominant systematic uncertainties from jet energy calibration is reduced by using a correction from `+jets channel. To replicate the quark avor dependence of the jet response in data, jets in the simulated events are additionally corrected. The result is combined with our preceding measurement on 1 fb-1 and yields mt = 174.0± 2.4 (stat.) ±1.4 (syst.) GeV.

  8. Quark mass variation constraints from Big Bang nucleosynthesis

    SciTech Connect

    Bedaque, P; Luu, T; Platter, L

    2010-12-13

    We study the impact on the primordial abundances of light elements created of a variation of the quark masses at the time of Big Bang nucleosynthesis (BBN). In order to navigate through the particle and nuclear physics required to connect quark masses to binding energies and reaction rates in a model-independent way we use lattice QCD data and an hierarchy of effective field theories. We find that the measured {sup 4}He abundances put a bound of {delta}-1% {approx}< m{sub q}/m{sub 1} {approx}< 0.7%. The effect of quark mass variations on the deuterium abundances can be largely compensated by changes of the baryon-to-photon ratio {eta}. Including the bounds on the variation of {eta} coming from WMAP results and some additional assumptions narrows the range of allowed values of {delta}m{sub q}/m{sub q} somewhat.

  9. Calibration of the Top-Quark Monte Carlo Mass

    NASA Astrophysics Data System (ADS)

    Kieseler, Jan; Lipka, Katerina; Moch, Sven-Olaf

    2016-04-01

    We present a method to establish, experimentally, the relation between the top-quark mass mtMC as implemented in Monte Carlo generators and the Lagrangian mass parameter mt in a theoretically well-defined renormalization scheme. We propose a simultaneous fit of mtMC and an observable sensitive to mt, which does not rely on any prior assumptions about the relation between mt and mtMC. The measured observable is independent of mtMC and can be used subsequently for a determination of mt. The analysis strategy is illustrated with examples for the extraction of mt from inclusive and differential cross sections for hadroproduction of top quarks.

  10. A top quark mass measurement using a matrix element method

    SciTech Connect

    Linacre, Jacob Thomas

    2009-01-01

    A measurement of the mass of the top quark is presented, using top-antitop pair (t$\\bar{t}$) candidate events for the lepton+jets decay channel. The measurement makes use of Tevatron p$\\bar{p}$ collision data at centre-of-mass energy √s = 1.96 TeV, collected at the CDF detector. The top quark mass is measured by employing an unbinned maximum likelihood method where the event probability density functions are calculated using signal (t$\\bar{t}$) and background (W+jets) matrix elements, as well as a set of parameterised jet-to-parton mapping functions. The likelihood function is maximised with respect to the top quark mass, the fraction of signal events, and a correction to the jet energy scale (JES) of the calorimeter jets. The simultaneous measurement of the JES correction (ΔJES) provides an in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using 578 lepton+jets candidate events corresponding to 3.2 fb -1 of integrated luminosity, the top quark mass is measured to be mt = 172.4± 1.4 (stat+ΔJES) ±1.3 (syst) GeV=c2, one of the most precise single measurements to date.

  11. Transverse momentum dependent quark densities from Lattice QCD

    SciTech Connect

    Bernhard Musch,Philipp Hagler,John Negele,Andreas Schafer

    2011-10-01

    We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. We discuss the basic concepts of the method, including renormalization of the gauge link. Results obtained with a simplified operator geometry show visible dipole deformations of spin-dependent quark momentum densities.

  12. Transverse momentum dependent quark densities from Lattice QCD

    SciTech Connect

    Musch, B. U.; Haegler, Ph.; Negele, J. W.; Schaefer, A.

    2011-10-24

    We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. We discuss the basic concepts of the method, including renormalization of the gauge link. Results obtained with a simplified operator geometry show visible dipole deformations of spin-dependent quark momentum densities.

  13. Precise measurement of the top-quark mass from lepton+jets events at D0

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2011-08-09

    We report a measurement of the mass of the top quark in lepton+jets final states of pp&3772; → tt̄ data corresponding to 2.6 fb-1 of integrated luminosity collected at the D0 experiment at the Fermilab Tevatron Collider. Using a matrix element method, we combine an in situ jet energy calibration with the standard jet energy scale derived in studies of Γ + jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quark mass of mt = 176.01 ± 1.64 GeV. Combining this result with a previous result obtained on an independent data set, we measure a top-quark mass of mt = 174.94 ± 1.49 GeV for a total integrated luminosity of 3.6 fb-1.

  14. Precise measurement of the top-quark mass from lepton+jets events at D0

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2011-08-09

    We report a measurement of the mass of the top quark in lepton+jets final states of pp&3772; → tt̄ data corresponding to 2.6 fb-1 of integrated luminosity collected at the D0 experiment at the Fermilab Tevatron Collider. Using a matrix element method, we combine an in situ jet energy calibration with the standard jet energy scale derived in studies of Γ + jet and dijet events and employ a novel flavor-dependent jet response correction to measure a top-quark mass of mt = 176.01 ± 1.64 GeV. Combining this result with a previous result obtained on an independent data set, wemore » measure a top-quark mass of mt = 174.94 ± 1.49 GeV for a total integrated luminosity of 3.6 fb-1.« less

  15. Top-quark mass measurement in the dilepton channel using in situ jet energy scale calibration

    NASA Astrophysics Data System (ADS)

    Lee, Hyun Su

    2012-09-01

    We employ a top-quark mass measurement technique in the dilepton channel with in situ jet energy scale calibration. Three variables having different jet energy scale dependences are used simultaneously to extract not only the top-quark mass but also the energy scale of the jet from a single likelihood fit. Monte Carlo studies with events corresponding to an integrated luminosity of 5fb-1 proton-proton collisions at the Large Hadron Collider s=7TeV are performed. Our analysis suggests that the overall jet energy scale uncertainty can be significantly reduced and the top-quark mass can be determined with a precision of less than 1GeV/c2, including jet energy scale uncertainty, at the Large Hadron Collider.

  16. Precision Top-Quark Mass Measurements at CDF

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2012-07-01

    We present a precision measurement of the top-quark mass using the full sample of Tevatron {radical}s = 1.96 TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 fb{sup -1}. Using a sample of t{bar t} candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the W boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with in situ calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, mtop = 172.85 {+-} 0.71 (stat) {+-} 0.85 (syst) GeV/c{sup 2}.

  17. Mass, quark-number, and {radical}(s{sub NN}) dependence of the second and fourth flow harmonics in ultrarelativistic nucleus-nucleus collisions

    SciTech Connect

    Abelev, B. I.; Baumgart, S.; Bielcik, J.; Bielcikova, J.; Caines, H.; Catu, O.; Chikanian, A.; Du, F.; Finch, E.; Harris, J. W.; Heinz, M.; Knospe, A. G.; Lamont, M. A. C.; Lin, G.; Majka, R.; Nattrass, C.; Salur, S.; Sandweiss, J.; Smirnov, N.; Witt, R.

    2007-05-15

    We present STAR measurements of the azimuthal anisotropy parameter v{sub 2} for pions, kaons, protons, {lambda},{lambda},{xi}+{xi}, and {omega}+{omega}, along with v{sub 4} for pions, kaons, protons, and {lambda}+{lambda} at midrapidity for Au+Au collisions at {radical}(s{sub NN})=62.4 and 200 GeV. The v{sub 2}(p{sub T}) values for all hadron species at 62.4 GeV are similar to those observed in 130 and 200 GeV collisions. For observed kinematic ranges, v{sub 2} values at 62.4, 130, and 200 GeV are as little as 10-15% larger than those in Pb+Pb collisions at {radical}(s{sub NN})=17.3 GeV. At intermediate transverse momentum (p{sub T} from 1.5-5 GeV/c), the 62.4 GeV v{sub 2}(p{sub T}) and v{sub 4}(p{sub T}) values are consistent with the quark-number scaling first observed at 200 GeV. A four-particle cumulant analysis is used to assess the nonflow contributions to pions and protons and some indications are found for a smaller nonflow contribution to protons than pions. Baryon v{sub 2} is larger than antibaryon v{sub 2} at 62.4 and 200 GeV, perhaps indicating either that the initial spatial net-baryon distribution is anisotropic, that the mechanism leading to transport of baryon number from beam- to midrapidity enhances v{sub 2} or that antibaryon and baryon annihilation is larger in the in-plane direction.

  18. Mass, quark-number, and sNN dependence of the second and fourth flow harmonics in ultrarelativistic nucleus-nucleus collisions

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Burton, T. P.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Callner, J.; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, S. U.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Dash, S.; Daugherity, M.; Moura, M. M. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, N.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D.; Hollis, R.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kurnadi, P.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Qattan, I. A.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schweda, K.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; Toledo, A. Szanto De; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Watson, J. W.; Webb, J. C.; Westfall, G. D.; Wetzler, A.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, J.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yurevich, V. I.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2007-05-01

    We present STAR measurements of the azimuthal anisotropy parameter v2 for pions, kaons, protons, Λ,Λ¯,Ξ+Ξ¯, and Ω+Ω¯, along with v4 for pions, kaons, protons, and Λ+Λ¯ at midrapidity for Au+Au collisions at sNN=62.4 and 200 GeV. The v2(pT) values for all hadron species at 62.4 GeV are similar to those observed in 130 and 200 GeV collisions. For observed kinematic ranges, v2 values at 62.4, 130, and 200 GeV are as little as 10 15% larger than those in Pb+Pb collisions at sNN=17.3 GeV. At intermediate transverse momentum (pT from 1.5 5 GeV/c), the 62.4 GeV v2(pT) and v4(pT) values are consistent with the quark-number scaling first observed at 200 GeV. A four-particle cumulant analysis is used to assess the nonflow contributions to pions and protons and some indications are found for a smaller nonflow contribution to protons than pions. Baryon v2 is larger than antibaryon v2 at 62.4 and 200 GeV, perhaps indicating either that the initial spatial net-baryon distribution is anisotropic, that the mechanism leading to transport of baryon number from beam- to midrapidity enhances v2 or that antibaryon and baryon annihilation is larger in the in-plane direction.

  19. Connecting Fermion Masses and Mixings to BSM Physics - Quarks

    NASA Astrophysics Data System (ADS)

    Goldman, Terrence; Stephenson, Gerard J., Jr.

    2015-10-01

    The ``democratic'' mass matrix with BSM physics assumptions has been studied without success. We invert the process and use the ``democratic'' mass matrix plus a parametrization of all possible BSM corrections to analyze the implications of the observed masses and CKM weak interaction current mixing for the BSM parameter values for the up-quarks and down-quarks. We observe that the small mixing of the so-called ``third generation'' is directly related to the large mass gap from the two lighter generations. Conversely, the relatively large value of the Cabibbo angle arises because the mass matrices in the light sub-sector (block diagonalized from the full three channel problem) are neither diagonal nor degenerate and differ significantly between the up and down cases. Alt email:t.goldman@gmail.com

  20. Statistical understanding of quark and lepton masses in Gaussian landscapes

    SciTech Connect

    Hall, Lawrence J.; Salem, Michael P.; Watari, Taizan

    2007-11-01

    The fundamental theory of nature may allow a large landscape of vacua. Even if the theory contains a unified gauge symmetry, the 22 flavor parameters of the standard model, including neutrino masses, may be largely determined by the statistics of this landscape, and not by any symmetry. Then the measured values of the flavor parameters do not lead to any fundamental symmetries, but are statistical accidents; their precise values do not provide any insights into the fundamental theory, rather the overall pattern of flavor reflects the underlying landscape. We investigate whether random selection from the statistics of a simple landscape can explain the broad patterns of quark, charged lepton, and neutrino masses and mixings. We propose Gaussian landscapes as simplified models of landscapes where Yukawa couplings result from overlap integrals of zero-mode wave functions in higher-dimensional supersymmetric gauge theories. In terms of just five free parameters, such landscapes can account for all gross features of flavor, including the hierarchy of quark and charged-lepton masses; small quark mixing angles in the basis with quarks arranged according to mass, with 13 mixing less than 12 and 23 mixing; very light Majorana neutrino masses, with the solar to atmospheric neutrino mass ratio consistent with data; distributions for leptonic mixings sin2{theta}{sub 12} and sin2{theta}{sub 23} that are peaked at large values, while the distribution for sin2{theta}{sub 13} is peaked at low values; and order unity CP-violating phases in both the quark and lepton sectors. While the statistical distributions for flavor parameters are broad, the distributions are robust to changes in the geometry of the extra dimensions. Constraining the distributions by loose cuts about observed values leads to narrower distributions for neutrino measurements of {theta}{sub 13}, CP violation, and neutrinoless double beta decay.

  1. Transverse momentum dependent quark densities from Lattice QCD

    SciTech Connect

    Bernhard Musch,Philipp Hagler,John Negele,Andreas Schafer

    2011-02-01

    We study transverse momentum dependent parton distribution functions (TMDs) with non-local operators in lattice QCD, using MILC/LHPC lattices. Results obtained with a simpli?ed operator geometry show visible dipole de- formations of spin-dependent quark momentum densities. We discuss the basic concepts of the method, including renormalization of the gauge link, and an ex- tension to a more elaborate operator geometry that would allow us to analyze process-dependent TMDs such as the Sivers-function.

  2. A precision measurement of the mass of the top quark.

    PubMed

    Abazov, V M; Abbott, B; Abdesselam, A; Abolins, M; Abramov, V; Acharya, B S; Adams, D L; Adams, M; Ahmed, S N; Alexeev, G D; Alton, A; Alves, G A; Arnoud, Y; Avila, C; Babintsev, V V; Babukhadia, L; Bacon, T C; Baden, A; Baffioni, S; Baldin, B; Balm, P W; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Bean, A; Beaudette, F; Begel, M; Belyaev, A; Beri, S B; Bernardi, G; Bertram, I; Besson, A; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Bhattacharjee, M; Blazey, G; Blekman, F; Blessing, S; Boehnlein, A; Bojko, N I; Bolton, T A; Borcherding, F; Bos, K; Bose, T; Brandt, A; Briskin, G; Brock, R; Brooijmans, G; Bross, A; Buchholz, D; Buehler, M; Buescher, V; Burtovoi, V S; Butler, J M; Canelli, F; Carvalho, W; Casey, D; Castilla-Valdez, H; Chakraborty, D; Chan, K M; Chekulaev, S V; Cho, D K; Choi, S; Chopra, S; Claes, D; Clark, A R; Connolly, B; Cooper, W E; Coppage, D; Crépé-Renaudin, S; Cummings, M A C; Cutts, D; Da Motta, H; Davis, G A; De, K; De Jong, S J; Demarteau, M; Demina, R; Demine, P; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Doulas, S; Dudko, L V; Duflot, L; Dugad, S R; Duperrin, A; Dyshkant, A; Edmunds, D; Ellison, J; Eltzroth, J T; Elvira, V D; Engelmann, R; Eno, S; Eppley, G; Ermolov, P; Eroshin, O V; Estrada, J; Evans, H; Evdokimov, V N; Ferbel, T; Filthaut, F; Fisk, H E; Fortner, M; Fox, H; Fu, S; Fuess, S; Gallas, E; Galyaev, A N; Gao, M; Gavrilov, V; Genik, R J; Genser, K; Gerber, C E; Gershtein, Y; Ginther, G; Gómez, B; Goncharov, P I; Gounder, K; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Grinstein, S; Groer, L; Grünendahl, S; Grünewald, M W; Gurzhiev, S N; Gutierrez, G; Gutierrez, P; Hadley, N J; Haggerty, H; Hagopian, S; Hagopian, V; Hall, R E; Han, C; Hansen, S; Hauptman, J M; Hebert, C; Hedin, D; Heinmiller, J M; Heinson, A P; Heintz, U; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Huang, J; Huang, Y; Iashvili, I; Illingworth, R; Ito, A S; Jaffré, M; Jain, S; Jesik, R; Johns, K; Johnson, M; Jonckheere, A; Jöstlein, H; Juste, A; Kahl, W; Kahn, S; Kajfasz, E; Kalinin, A M; Karmanov, D; Karmgard, D; Kehoe, R; Kesisoglou, S; Khanov, A; Kharchilava, A; Klima, B; Kohli, J M; Kostritskiy, A V; Kotcher, J; Kothari, B; Kozelov, A V; Kozlovsky, E A; Krane, J; Krishnaswamy, M R; Krivkova, P; Krzywdzinski, S; Kubantsev, M; Kuleshov, S; Kulik, Y; Kunori, S; Kupco, A; Kuznetsov, V E; Landsberg, G; Lee, W M; Leflat, A; Lehner, F; Leonidopoulos, C; Li, J; Li, Q Z; Lima, J G R; Lincoln, D; Linn, S L; Linnemann, J; Lipton, R; Lucotte, A; Lueking, L; Lundstedt, C; Luo, C; Maciel, A K A; Madaras, R J; Malyshev, V L; Manankov, V; Mao, H S; Marshall, T; Martin, M I; Mattingly, S E K; Mayorov, A A; McCarthy, R; McMahon, T; Melanson, H L; Melnitchouk, A; Merkin, A; Merritt, K W; Miao, C; Miettinen, H; Mihalcea, D; Mokhov, N; Mondal, N K; Montgomery, H E; Moore, R W; Mutaf, Y D; Nagy, E; Narain, M; Narasimham, V S; Naumann, N A; Neal, H A; Negret, J P; Nelson, S; Nomerotski, A; Nunnemann, T; O'Neil, D; Oguri, V; Oshima, N; Padley, P; Papageorgiou, K; Parashar, N; Partridge, R; Parua, N; Patwa, A; Peters, O; Pétroff, P; Piegaia, R; Pope, B G; Prosper, H B; Protopopescu, S; Przybycien, M B; Qian, J; Rajagopalan, S; Rapidis, P A; Reay, N W; Reucroft, S; Ridel, M; Rijssenbeek, M; Rizatdinova, F; Rockwell, T; Royon, C; Rubinov, P; Ruchti, R; Sabirov, B M; Sajot, G; Santoro, A; Sawyer, L; Schamberger, R D; Schellman, H; Schwartzman, A; Shabalina, E; Shivpuri, R K; Shpakov, D; Shupe, M; Sidwell, R A; Simak, V; Sirotenko, V; Slattery, P; Smith, R P; Snow, G R; Snow, J; Snyder, S; Solomon, J; Song, Y; Sorín, V; Sosebee, M; Sotnikova, N; Soustruznik, K; Souza, M; Stanton, N R; Steinbrück, G; Stoker, D; Stolin, V; Stone, A; Stoyanova, D A; Strang, M A; Strauss, M; Strovink, M; Stutte, L; Sznajder, A; Talby, M; Taylor, W; Tentindo-Repond, S; Trippe, T G; Turcot, A S; Tuts, P M; Van Kooten, R; Vaniev, V; Varelas, N; Villeneuve-Seguier, F; Volkov, A A; Vorobiev, A P; Wahl, H D; Wang, Z-M; Warchol, J; Watts, G; Wayne, M; Weerts, H; White, A; Whiteson, D; Wijngaarden, D A; Willis, S; Wimpenny, S J; Womersley, J; Wood, D R; Xu, Q; Yamada, R; Yasuda, T; Yatsunenko, Y A; Yip, K; Yu, J; Zanabria, M; Zhang, X; Zhou, B; Zhou, Z; Zielinski, M; Zieminska, D; Zieminski, A; Zutshi, V; Zverev, E G; Zylberstejn, A

    2004-06-10

    The standard model of particle physics contains parameters--such as particle masses--whose origins are still unknown and which cannot be predicted, but whose values are constrained through their interactions. In particular, the masses of the top quark (M(t)) and W boson (M(W)) constrain the mass of the long-hypothesized, but thus far not observed, Higgs boson. A precise measurement of M(t) can therefore indicate where to look for the Higgs, and indeed whether the hypothesis of a standard model Higgs is consistent with experimental data. As top quarks are produced in pairs and decay in only about 10(-24) s into various final states, reconstructing their masses from their decay products is very challenging. Here we report a technique that extracts more information from each top-quark event and yields a greatly improved precision (of +/- 5.3 GeV/c2) when compared to previous measurements. When our new result is combined with our published measurement in a complementary decay mode and with the only other measurements available, the new world average for M(t) becomes 178.0 +/- 4.3 GeV/c2. As a result, the most likely Higgs mass increases from the experimentally excluded value of 96 to 117 GeV/c2, which is beyond current experimental sensitivity. The upper limit on the Higgs mass at the 95% confidence level is raised from 219 to 251 GeV/c2. PMID:15190311

  3. Constituent quark masses obtained from hadron masses with contributions of Fermi-Breit and Glozman-Riska hyperfine interactions

    SciTech Connect

    Borka Jovanovic, V.; Borka, D.; Ignjatovic, S. R.; Jovanovic, P.

    2010-12-01

    We use the color-spin and flavor-spin interaction Hamiltonians with SU(3) flavor symmetry breaking to obtain meson and baryon mass formulas. Adjusting these masses with experimental masses we determine the constituent quark masses. We discuss the constituent quark masses obtained from meson and baryon mass fits. The results for constituent quark masses are very similar in the case of two different phenomenological models: Fermi-Breit and Glozman-Riska hyperfine interactions.

  4. Measurements of the top quark mass at the Tevatron

    SciTech Connect

    Brandt, Oleg; /Gottingen U., II. Phys. Inst.

    2012-04-01

    The mass of the top quark (m{sub top}) is a fundamental parameter of the standard model (SM). Currently, its most precise measurements are performed by the CDF and D0 collaborations at the Fermilab Tevatron p{bar p} collider at a centre-of-mass energy of {radical}s = 1.96 TeV. We review the most recent of those measurements, performed on data samples of up to 8.7 fb{sup -1} of integrated luminosity. The Tevatron combination using up to 5.8 fb{sup -1} of data results in a preliminary world average top quark mass of m{sub top} = 173.2 {+-} 0.9 GeV. This corresponds to a relative precision of about 0.54%. We conclude with an outlook of anticipated precision the final measurement of m{sub top} at the Tevatron.

  5. Measurements of the top-quark mass using charged particle tracking

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-10-01

    We present three measurements of the top-quark mass in the lepton plus jets channel with approximately 1.9 fb{sup -1} of integrated luminosity collected with the CDF II detector using quantities with minimal dependence on the jet energy scale. One measurement exploits the transverse decay length of b-tagged jets to determine a top-quark mass of 166.9{sub -8.5}{sup +9.5} (stat) {+-} 2.9 (syst) GeV/c{sup 2}, and another the transverse momentum of electrons and muons from W-boson decays to determine a top-quark mass of 173.5{sub -8.9}{sup +8.8} (stat) {+-} 3.8 (syst) GeV/c{sup 2}. These quantities are combined in a third, simultaneous mass measurement to determine a top-quark mass of 170.7 {+-} 6.3 (stat) {+-} 2.6 (syst) GeV/c{sup 2}.

  6. Measurements of the top quark mass and decay width with the D0 detector

    SciTech Connect

    Ilchenko, Yuriy

    2011-11-01

    The top quark discovery in 1995 at Fermilab is one of the major proofs of the standard model (SM). Due to its unique place in SM, the top quark is an important particle for testing the theory and probing for new physics. This article presents most recent measurements of top quark properties from the D0 detector. In particular, the measurement of the top quark mass, the top antitop mass difference and the top quark decay width. The discovery of the top quark in 1995 confirmed the existence of a third generation of quarks predicted in the standard model (SM). Being the heaviest elementary particle known, the top quark appears to become an important particle in our understanding of the standard model and physics beyond it. Because of its large mass the top quark has a very short lifetime, much shorter than the hadronization time. The predicted lifetime is only 3.3 {center_dot} 10{sup -25}s. Top quark is the only quark whose properties can be studied in isolation. A Lorentz-invariant local Quantum Field Theory, the standard model is expected to conserve CP. Due to its unique properties, the top quark provides a perfect test of CPT invariance in the standard model. An ability to look at the quark before being hadronized allows to measure directly mass of the top quark and its antiquark. An observation of a mass difference between particle and antiparticle would indicate violation of CPT invariance. Top quark through its radiative loop correction to the W mass constrains the mass of the Higgs boson. A precise measurement of the top quark mass provides useful information to the search of Higgs boson by constraining its region of possible masses. Another interesting aspect is that the top quark's Yukawa coupling to the Higgs boson is very close to unity (0.996 {+-} 0.006). That implies it may play a special role in the electroweak symmetry breaking mechanism.

  7. Top quark and Higgs boson masses from wormhole physics

    SciTech Connect

    Harris, B.A.; Joshi, G.C. )

    1994-11-01

    We bring together quantum field theory on [ital S][sub 4] with the Coleman wormhole hypothesis, which imposes constraints on terms in the gravitational Lagrangian. In particular, we investigate the effect of matter fields on the trace anomaly, which is related to the (curvature)[sup 2] terms, by the use of the renormalization group equations. We consider a toy model of a nonconformally coupled Higgs boson to a single top'' quark. By numerically solving the renormalization group equations for the couplings of the model, we can find preferred values of the particle masses for various values of the bare nonconformal coupling. By making the [ital ad] [ital hoc] assumption that the tree-level, Higgs boson treace anomaly vanishes on shell, a unique prediction can be made within this model for the masses of both the Higgs boson and the top quark.

  8. Heavy-quark mass effects in Higgs plus jets production

    NASA Astrophysics Data System (ADS)

    Frederix, R.; Frixione, S.; Vryonidou, E.; Wiesemann, M.

    2016-08-01

    We study the production of a Standard Model Higgs boson in the gluon-fusion channel at the 13 TeV LHC. Our results are accurate to the next-to-leading order in QCD, bar for the lack of some two-loop amplitudes, for up to two extra jets and are matched to the P ythia8 Monte Carlo. We address the impact, at the level of inclusive rates and of differential distributions, of the merging of samples characterised by different final-state multiplicities, and of the effects induced by top and bottom masses through heavy-quark loop diagrams. We find that both the merging and the heavy-quark masses must be included in the calculation in order to realistically predict observables of experimental interest.

  9. Measurement of the Top Quark Mass at CDF II

    SciTech Connect

    Kovalev, Andrew N

    2003-11-01

    The authors describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II Detector from p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron. The posterior probability distribution of the top quark pole mass is calculated using the differential cross-section for the t{bar t} production and decay expressed with respect to observed leptons and jets momenta. The presence of background events in the collected sample is modeled using calculations of the differential cross-sections for major background processes. This measurement represents the first application of this method to events with two charged leptons. In a data sample with integrated luminosity of 340 pb{sup -1}, they observe 33 candidate events and measure M{sub top} = 165.2 {+-} 61.{sub stat} {+-} 3.4{sub syst} GeV/c{sup 2}.

  10. Bottom quark contribution to spin-dependent dark matter detection

    NASA Astrophysics Data System (ADS)

    Li, Jinmian; Thomas, Anthony W.

    2016-05-01

    We investigate a previously overlooked bottom quark contribution to the spin-dependent cross section for Dark Matter (DM) scattering from the nucleon. While the mechanism is relevant to any supersymmetric extension of the Standard Model, for illustrative purposes we explore the consequences within the framework of the Minimal Supersymmetric Standard Model (MSSM). We study two cases, namely those where the DM is predominantly Gaugino or Higgsino. In both cases, there is a substantial, viable region in parameter space (mb˜ -mχ ≲ O (100) GeV) in which the bottom contribution becomes important. We show that a relatively large contribution from the bottom quark is consistent with constraints from spin-independent DM searches, as well as some incidental model dependent constraints.

  11. Top quark mass measurement at CDF Run-II

    SciTech Connect

    T. Maruyama

    2004-05-11

    CDF has resumed the top quark mass measurement with upgraded detectors and Tevatron complex. High statistics should allow us to determine the top mass with an uncertainty of a few GeV/c{sup 2} by the end of Run II. The current measured value, using an integrated luminosity of {approx} 108 pb{sup -1}, is 177.5{sub -9.4}{sup +12.7} (stat.) {+-} 7.1(syst.) GeV/c{sup 2} (lepton + jets with one b-jet tagged mode: the current best mode), which is consistent with RunI measurements.

  12. Measurement of the top quark mass at D0

    SciTech Connect

    Petrillo, Gianluca

    2010-01-01

    The most recent measurements of the mass of the quark top at D0 are reviewed. The analysis methods include the direct measurement by Matrix Element and Weighting method and the indirect measurement from t{bar t} production cross section. They have been applied on different experimental signatures, all including at least one electron or muon. Measurements include from 1 to 3.6 fb{sup -1} of D0 data. The most recent combination of mass measurements from D0 and from CDF are also quoted.

  13. Magnetic moments of JP=3/2+ decuplet baryons using effective quark masses in a chiral constituent quark model

    NASA Astrophysics Data System (ADS)

    Girdhar, Aarti; Dahiya, Harleen; Randhawa, Monika

    2015-08-01

    The magnetic moments of JP=3/2+ decuplet baryons have been calculated in the chiral constituent quark model (χ CQM ) with explicit results for the contribution coming from the valence quark polarizations, sea quark polarizations, and their orbital angular momentum. Since the JP=3/2+ decuplet baryons have short lifetimes, the experimental information about them is limited. The χ CQM has important implications for chiral symmetry breaking as well as SU(3) symmetry breaking since it works in the region between the QCD confinement scale and the chiral symmetry breaking scale. The predictions in the model not only give a satisfactory fit when compared with the experimental data but also show improvement over the other models. The effect of the confinement on quark masses has also been discussed in detail and the results of χ CQM are found to improve further with the inclusion of effective quark masses.

  14. Many Masses on One Stroke:. Economic Computation of Quark Propagators

    NASA Astrophysics Data System (ADS)

    Frommer, Andreas; Nöckel, Bertold; Güsken, Stephan; Lippert, Thomas; Schilling, Klaus

    The computational effort in the calculation of Wilson fermion quark propagators in Lattice Quantum Chromodynamics can be considerably reduced by exploiting the Wilson fermion matrix structure in inversion algorithms based on the non-symmetric Lanczos process. We consider two such methods: QMR (quasi minimal residual) and BCG (biconjugate gradients). Based on the decomposition M/κ = 1/κ-D of the Wilson mass matrix, using QMR, one can carry out inversions on a whole trajectory of masses simultaneously, merely at the computational expense of a single propagator computation. In other words, one has to compute the propagator corresponding to the lightest mass only, while all the heavier masses are given for free, at the price of extra storage. Moreover, the symmetry γ5M = M†γ5 can be used to cut the computational effort in QMR and BCG by a factor of two. We show that both methods then become — in the critical regime of small quark masses — competitive to BiCGStab and significantly better than the standard MR method, with optimal relaxation factor, and CG as applied to the normal equations.

  15. Universal form for quark and lepton mass matrices

    NASA Astrophysics Data System (ADS)

    Gu, Zheng-Cheng; Preskill, John

    2015-12-01

    We propose a universal form for quark and lepton mass matrices, which applies in a "leading order" approximation where C P -violating phases are ignored. Down-quark mass ratios are successfully predicted in our scheme using the measured Cabibbo-Kobayashi-Maskawa mixing angles as input. Assuming an additional discrete symmetry in the neutrino sector, we obtain the "golden ratio" pattern in the leading-order Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix; in addition we predict an inverted neutrino mass hierarchy with m1≃m2≃74 meV , m3≃55 meV , and neutrinoless double beta decay mass parameter m0 ν β β≃33 meV . When C P -violating phases are included, our scheme suggests a residual Z 2 antiunitary symmetry of the neutrino mass matrix, in which the interchange of μ and τ neutrinos is accompanied by a time reversal transformation, thus predicting that the C P -violating angle in the neutrino sector is close to the maximal value δ =±π /2 , and that the diagonal phases in the PMNS matrix are α1≃0 , α2≃π .

  16. Pion and Kaon Masses and Pion Form Factors from Dynamical Chiral-Symmetry Breaking with Light Constituent Quarks

    SciTech Connect

    Scadron, Michael D.; Kleefeld, Frieder; Rupp, George

    2007-02-27

    Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the quark-level linear {sigma} model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses, which reproduce the experimental pion and kaon masses very accurately, by simple additivity. In contrast, the usual nonstrange and strange current quarks employed by the Particle Data Group and Chiral Perturbation Theory do not allow a straightforward quantitative explanation of the pion and kaon masses.

  17. Top Quark Mass from the Tevatron and LHC Colliders

    NASA Astrophysics Data System (ADS)

    Brigliadori, Luca

    2015-03-01

    The discovery of the top quark in 1995 has been one of the great successes of the CDF and D0 experiments at the Fermilab Tevatron collider. Since then, many measurements of the top quark properties have been performed in different channels and using many methods. The importance of measuring its mass lies in the possibility of verifying the predictions and the consistency of the Standard Model as well as in setting constraints on possible, still unobserved, physics. In 2010, the new CERN experiments, ATLAS and CMS, started to measure the top quark properties exploiting the large amount of data collected at the Large Hadron Collider. In March 2014, the very first combination of measurements from all the four experiments has been performed yielding Mtop = 173.34 ± 0.76 GeV, with a precision below 0.5%. In these proceedings a selected review of the most recent or relevant results obtained by the Tevatron and LHC Collaborations is presented.

  18. Lattice investigation of nucleon structure at light quark masses

    SciTech Connect

    Zanotti, James M.

    2010-07-27

    Lattice simulations of hadronic structure are now reaching a level where they are able to not only complement, but also provide guidance to current and forthcoming experimental programmes at, e.g. Jefferson Lab, COMPASS/CERN and FAIR/GSI. By considering new simulations at low quark masses and on large volumes, we review the recent progress that has been made in this exciting area by the QCDSF/UKQCD collaboration. In particular, results obtained close to the physical point for several quantities, including electromagnetic form factors and moments of ordinary parton distribution functions, show some indication of approaching their phenomenological values.

  19. Measurement of the top quark mass at D0

    SciTech Connect

    Varnes, E.W.; D0 Collaboration

    1996-11-01

    D{null} has measured the top quark mass using a sample of 32 single- lepton events selected from approximately 115 pb{sup -1} of {radical}s = 1.8 TeV {ital p}{ital {anti p}} collisions collected from 1992-1996. The result is {ital m}{sub t} = 169 {+-} 8({ital stat}){+-} 8 ({ital syst}) GeV/c{sup 2}. Using a sample of 3 {ital e{mu}} events, D{null} measures {ital m}{sub t} = 158 {+-} 24({ital stat}) {+-} 10({ital syst}) GeV/c{sup 2}.

  20. Top quark mass measurement from dilepton events at CDF II

    SciTech Connect

    Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara /Cantabria Inst. of Phys.

    2005-12-01

    We report a measurement of the top quark mass using events collected by the CDF II Detector from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron. We calculate a likelihood function for the top mass in events that are consistent with t{bar t} {yields} {bar b}{ell}{sup -}{bar {nu}}{sub {ell}}b{ell}{prime}{sup +}{nu}{sub {ell}}{prime} decays. The likelihood is formed as the convolution of the leading-order matrix element and detector resolution functions. The joint likelihood is the product of likelihoods for each of 33 events collected in 340 pb{sup -1} of integrated luminosity, yielding a top quark mass M{sub t} = 165.2 {+-} 6.1(stat.) {+-} 3.4(syst.) GeV/c{sup 2}. This first application of a matrix-element technique to t{bar t} {yields} b{ell}{sup +}{nu}{sub {ell}}{bar b}{ell}{prime}{sup -}{bar {nu}}{sub {ell}}, decays gives the most precise single measurement of M{sub t} in dilepton events. Combined with other CDF Run II measurements using dilepton events, we measure M{sub t} = 167.9 {+-} 5.2(stat.) {+-} 3.7(syst.) GeV/c{sup 2}.

  1. General structure of democratic mass matrix of quark sector in E6 model

    NASA Astrophysics Data System (ADS)

    Ciftci, R.; ćiftci, A. K.

    2016-03-01

    An extension of the Standard Model (SM) fermion sector, which is inspired by the E6 Grand Unified Theory (GUT) model, might be a good candidate to explain a number of unanswered questions in SM. Existence of the isosinglet quarks might explain great mass difference of bottom and top quarks. Also, democracy on mass matrix elements is a natural approach in SM. In this study, we have given general structure of Democratic Mass Matrix (DMM) of quark sector in E6 model.

  2. Up, down, strange and charm quark masses with Nf=2+1+1 twisted mass lattice QCD

    NASA Astrophysics Data System (ADS)

    Carrasco, N.; Deuzeman, A.; Dimopoulos, P.; Frezzotti, R.; Giménez, V.; Herdoiza, G.; Lami, P.; Lubicz, V.; Palao, D.; Picca, E.; Reker, S.; Riggio, L.; Rossi, G. C.; Sanfilippo, F.; Scorzato, L.; Simula, S.; Tarantino, C.; Urbach, C.; Wenger, U.

    2014-10-01

    We present a lattice QCD calculation of the up, down, strange and charm quark masses performed using the gauge configurations produced by the European Twisted Mass Collaboration with Nf=2+1+1 dynamical quarks, which include in the sea, besides two light mass degenerate quarks, also the strange and charm quarks with masses close to their physical values. The simulations are based on a unitary setup for the two light quarks and on a mixed action approach for the strange and charm quarks. The analysis uses data at three values of the lattice spacing and pion masses in the range 210-450 MeV, allowing for accurate continuum limit and controlled chiral extrapolation. The quark mass renormalization is carried out non-perturbatively using the RI‧-MOM method. The results for the quark masses converted to the MSbar scheme are: mud(2 GeV)=3.70(17) MeV, ms(2 GeV)=99.6(4.3) MeV and mc(mc)=1.348(46) GeV. We obtain also the quark mass ratios ms/mud=26.66(32) and mc/ms=11.62(16). By studying the mass splitting between the neutral and charged kaons and using available lattice results for the electromagnetic contributions, we evaluate mu/md=0.470(56), leading to mu=2.36(24) MeV and md=5.03(26) MeV.

  3. Measurements of the top-quark mass and properties at CMS

    NASA Astrophysics Data System (ADS)

    Dünser, Marc; CMS Collaboration

    2015-06-01

    Measurements of the top-quark mass and other top-quark properties are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8 TeV. The mass of the top quark is measured using several methods and decay channels. The measurements of the top-quark properties include the W helicity in top-quark decays, the search for anomalous couplings, and the ratio of top-quarks decaying to bW over qW in order to gain information on |Vtb| using both t\\bar t and single-top quark event samples. The results are compared with predictions from the standard model as well as new physics models. The cross section of t\\bar t events produced in association with a W, Z boson or a photon is also measured.

  4. Measurement of the mass difference between top and antitop quarks

    SciTech Connect

    Chatrchyan, Serguei; et al.

    2012-06-01

    A measurement of the mass difference between the top and the antitop quark (Delta m(t) = m(t) - m(anti-t)) is performed using events with a muon or an electron and at least four jets in the final state. The analysis is based on data collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 4.96 +/- 0.11 inverse femtobarns, and yields the value of Delta m(t) = -0.44 +/- 0.46 (stat) +/- 0.27 (syst) GeV. This result is consistent with equality of particle and antiparticle masses required by CPT invariance, and provides a significantly improved precision relative to existing measurements.

  5. 1{sup -+} exotic meson at light quark masses

    SciTech Connect

    Hedditch, J.N.; Kamleh, W.; Lasscock, B.G.; Leinweber, D.B.; Williams, A.G.; Zanotti, J.M.

    2005-12-01

    The mass of the 1{sup -+} exotic meson, created with hybrid interpolating fields, is explored in numerical simulations of quenched QCD on large (20{sup 3}x40) lattices to obtain good control of statistical and finite volume errors. Using the Fat-Link Irrelevant Clover (FLIC) fermion action, the properties of the 1{sup -+} are investigated at light quark masses approaching 25 MeV (m{sub {pi}}/m{sub {rho}}{approx_equal}1/3). Under the standard assumption that the coupling to the quenched a{sub 1}{eta}{sup '} channel comes with a negative metric, our results indicate that the 1{sup -+} exotic exhibits significant curvature close to the chiral limit, suggesting previous linear extrapolations have overestimated the mass of the 1{sup -+}. We find for the first time in lattice studies a 1{sup -+} mass consistent with the {pi}{sub 1}(1600) candidate. We also find a strangeness {+-}1 J{sup P}=1{sup -} state with a mass close to 2 GeV.

  6. Quark and lepton masses and mixing in the landscape

    SciTech Connect

    Donoghue, John F.; Dutta, Koushik; Ross, Andreas

    2006-06-01

    Even if quark and lepton masses are not uniquely predicted by the fundamental theory, as may be the case in the string theory landscape, nevertheless their pattern may reveal features of the underlying theory. We use statistical techniques to show that the observed masses appear to be representative of a scale-invariant distribution, {rho}(m){approx}1/m. If we extend this distribution to include all the Yukawa couplings, we show that the resulting Cabibbo-Kobayashi-Maskawa matrix elements typically show a hierarchical pattern similar to observations. The Jarlskog invariant measuring the amount of CP violation is also well reproduced in magnitude. We also apply this framework to neutrinos using the seesaw mechanism. The neutrino results are ambiguous, with the observed pattern being statistically allowed even though the framework does not provide a natural explanation for the observed two large mixing angles. Our framework highly favors a normal hierarchy of neutrino masses. We also are able to make statistical predictions in the neutrino sector when we specialize to situations consistent with the known mass differences and two large mixing angles. Within our framework, we show that with 95% confidence the presently unmeasured Maki-Nakagawa-Sakata mixing angle sin{theta}{sub 13} is larger than 0.04 and typically of order 0.1. The leptonic Jarlskog invariant is found to be typically of order 10{sup -2} and the magnitude of the effective Majorana mass m{sub ee} is typically of order 0.001 eV.

  7. Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

    SciTech Connect

    Chevalier-Thery, Solene

    2010-06-01

    The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

  8. On the light quark mass effects in Higgs boson production in gluon fusion

    NASA Astrophysics Data System (ADS)

    Melnikov, Kirill; Penin, Alexander

    2016-05-01

    Production of Higgs bosons at the LHC is affected by the contribution of light quarks, that mediate the gg → Hg transition. Although their impact is suppressed by small Yukawa couplings, it is enhanced by large logarithms of the ratio of the Higgs boson mass or its transverse momentum to light quark masses. We study the origin of this enhancement, focusing on the abelian corrections to gg → Hg amplitudes of the form {({C}_F{α}_s{mathcal{L}}^2)}^n , where mathcal{L}in \\{ ln (s/{m}_b^2),kern0.5em ln ({p}_{perp}^2/{m}_b^2)\\} . We show how these non-Sudakov double logarithmic terms can be resummed to all orders in the strong coupling constant. Interestingly, we find that the transverse momentum dependence of these corrections is very weak due to a peculiar cancellation between different logarithmic terms. Although the abelian part of QCD corrections is not expected to be dominant, it can be used to estimate missing higher-order corrections to light quark contributions to Higgs boson production at the LHC.

  9. Quark mass relations to four-loop order in perturbative QCD.

    PubMed

    Marquard, Peter; Smirnov, Alexander V; Smirnov, Vladimir A; Steinhauser, Matthias

    2015-04-10

    We present results for the relation between a heavy quark mass defined in the on-shell and minimal subtraction (MS[over ¯]) scheme to four-loop order. The method to compute the four-loop on-shell integral is briefly described and the new results are used to establish relations between various short-distance masses and the MS[over ¯] quark mass to next-to-next-to-next-to-leading order accuracy. These relations play an important role in the accurate determination of the MS[over ¯] heavy quark masses. PMID:25910112

  10. Hadron energy spectrum in polarized top-quark decays considering the effects of hadron and bottom quark masses

    NASA Astrophysics Data System (ADS)

    Nejad, S. Mohammad Moosavi; Balali, Mahboobe

    2016-03-01

    We present the analytical expressions for the next-to-leading order corrections to the partial decay width t(\\uparrow ) rightarrow bW^+, followed by brightarrow H_bX, for nonzero b-quark mass (m_bne 0) in the fixed-flavor-number scheme (FFNs). To make the predictions for the energy distribution of outgoing hadrons H_b, as a function of the normalized H_b-energy fraction x_H, we apply the general-mass variable-flavor-number scheme (GM-VFNs) in a specific helicity coordinate system where the polarization of top quark is evaluated relative to the b-quark momentum. We also study the effects of gluon fragmentation and finite hadron mass on the hadron energy spectrum so that hadron masses are responsible for the low-x_H threshold. In order to describe both the b-quark and the gluon hadronizations in top decays we apply realistic and nonperturbative fragmentation functions extracted through a global fit to the e^+e^- annihilation data from CERN LEP1 and SLAC SLC by relying on their universality and scaling violations.

  11. Mass of the b quark and B -meson decay constants from Nf=2 +1 +1 twisted-mass lattice QCD

    NASA Astrophysics Data System (ADS)

    Bussone, A.; Carrasco, N.; Dimopoulos, P.; Frezzotti, R.; Lami, P.; Lubicz, V.; Picca, E.; Riggio, L.; Rossi, G. C.; Simula, S.; Tarantino, C.; ETM Collaboration

    2016-06-01

    We present precise lattice computations for the b -quark mass, the quark mass ratios mb/mc and mb/ms as well as the leptonic B -decay constants. We employ gauge configurations with four dynamical quark flavors, up-down, strange and charm, at three values of the lattice spacing (a ˜0.06 - 0.09 fm ) and for pion masses as low as 210 MeV. Interpolation in the heavy quark mass to the bottom quark point is performed using ratios of physical quantities computed at nearby quark masses exploiting the fact that these ratios are exactly known in the static quark mass limit. Our results are also extrapolated to the physical pion mass and to the continuum limit and read mb(MS ¯ ,mb)=4.26 (10 ) GeV , mb/mc=4.42 (8 ), mb/ms=51.4 (1.4 ), fB s=229 (5 ) MeV , fB=193 (6 ) MeV , fB s/fB=1.184 (25 ) and (fB s/fB)/(fK/fπ)=0.997 (17 ).

  12. Light hadron spectroscopy in two-flavor QCD with small sea quark masses

    SciTech Connect

    Namekawa, Y.; Aoki, S.; Iwasaki, Y.; Kanaya, K.; Fukugita, M.; Ishikawa, K.-I.; Ishizuka, N.; Ukawa, A.; Yoshie, T.; Kaneko, T.; Kuramashi, Y.; Lesk, V. I.; Umeda, T.; Okawa, M.

    2004-10-01

    We extend the study of the light hadron spectrum and the quark mass in two-flavor QCD to smaller sea quark mass, corresponding to m{sub PS}/m{sub V}=0.60-0.35. Numerical simulations are carried out using the RG-improved gauge action and the meanfield-improved clover quark action at {beta}=1.8 (a=0.2 fm from {rho} meson mass). We observe that the light hadron spectrum for small sea quark mass does not follow the expectation from chiral extrapolations with quadratic functions made from the region of m{sub PS}/m{sub V}=0.80-0.55. Whereas fits with either polynomial or continuum chiral perturbation theory (ChPT) fail, the Wilson ChPT (WChPT) that includes a{sup 2} effects associated with explicit chiral symmetry breaking successfully fits the whole data: In particular, WChPT correctly predicts the light quark mass spectrum from simulations for medium heavy quark mass, such as m{sub PS}/m{sub V} > or approx. 0.5. Reanalyzing the previous data with the use of WChPT, we find the mean up and down quark mass being smaller than the previous result from quadratic chiral extrapolation by approximately 10%, m{sub ud}{sup MS-bar}({mu}=2 GeV)=3.11(17) [MeV] in the continuum limit.

  13. Analysis of the QCD spectrum and chiral symmetry breaking with varying quark masses

    SciTech Connect

    Simonov, Yu. A.

    2013-04-15

    The meson spectrum of QCD is studied in the framework of nonperturbative QCD as a function of varying quark masses m{sub q}. It is shown that the total spectrum consists of two branches: 1) the standard one, which may be called the flux-tube spectrum, depending approximately linearly on m{sub q}, and 2) the chiral symmetry breaking (CSB) spectrum for pseudoscalar (PS) flavor nonsinglet mesons with mass dependence {radical}m{sub q}. The formalism for PS mesons is derived from the QCD Lagrangian with m{sub q} corrections, and a unified form of the PS propagator was derived. It is shown that the CSB branch of PS mesons joins to the flux-tube branch at around m{sub q} = 200 MeV. All these results are in close correspondence with recent numerical data on large lattices.

  14. Top-quark pole mass in the tadpole-free MS ¯ scheme

    NASA Astrophysics Data System (ADS)

    Martin, Stephen P.

    2016-05-01

    The complex pole mass of the top quark is presented at full two-loop order in the Standard Model, augmenting the known four-loop QCD contributions. The input parameters are the MS ¯ Yukawa and gauge couplings, the Higgs self-coupling, and the Higgs vacuum expectation value (VEV). Here, the VEV is defined as the minimum of the full effective potential in Landau gauge, so that tadpoles vanish. This is an alternative to earlier results that instead minimize the tree-level potential, resulting in a VEV that is gauge-fixing independent but accompanied by negative powers of the Higgs self-coupling in perturbative expansions. The effects of nonzero Goldstone boson mass are eliminated by resummation. I also study the renormalization scale dependence of the calculated pole mass.

  15. Measurement of the Top Quark Mass in the Di-lepton Channel using the Dalitz-Goldstein Method

    SciTech Connect

    Hare, Matthew Frederick

    2010-10-01

    This dissertation describes a measurement of the mass of the top quark using a method developed by G. Goldstein and R.H. Dalitz. It is based on 2.0 fb-1 of data collected by the Collider Detector Facility at Fermi National Accelerator Laboratories. Di-lepton events were observed from colliding protons with anti-protons with √s = 1.96 TeV in the Tevatron Collider. A total of 145 candidate events were observed with 49 expected to be from background. These events include two neutrinos which elude detection. The method begins by assuming an initial top quark mass and solves for the neutrino momenta using a geometrical construction. The method samples over a range of likely top quark masses choosing the most consistent mass via a likelihood function. An important distinguishing feature of this method from others is its lack of dependence on the missing transverse energy, a quantity that is poorly measured by the experiment. This analysis determines the top quark mass to be Mtop = 172.3 ± 3.4(stat.) ± 2.0(syst.) GeV/c2 (Mtop = 170.5 ± 3.7(stat.) ± 1.8(syst.) GeV/c2 with b-tagging).

  16. Di-lepton Top Quark Mass Measurement with the Neutrino Weighting Algorithm

    NASA Astrophysics Data System (ADS)

    Sabik, Simon

    2005-04-01

    We report a measurement of the Top Quark Mass using approximately 340 pb-1 of data from pp collisions at √s = 1.96 GeV at CDF Run II. We select tt candidates that are consistent with two W bosons decaying leptonically. Only one of the two charged leptons is required to be identified as an electron or a muon candidate, while the other is simply a well measured track. Using the Neutrino Weighting Algorithm to reconstruct a top quark mass in each event and comparing the resulting distribution to Monte Carlo templates, we measure the top quark mass.

  17. Precise measurement of the top quark mass in the lepton+jets topology at CDF II

    SciTech Connect

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; Antos, J.; /Comenius U. /Tsukuba U.

    2007-03-01

    The authors present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. They analyze events from the single lepton plus jets final state (t{bar t} {yields} W{sup +}bW{sup -}{bar b} {yields} lvbq{bar q}{bar b}). The top quark mass is extracted using a direct calculation of the probability density that each event corresponds to the t{bar t} final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb{sup -1} of integrated luminosity, they achieve the single most precise measurement of the top quark mass, 170.8 {+-} 2.2(stat.) {+-} 1.4(syst.) GeV/c{sup 2}.

  18. Quark masses and mixings in the RS1 model with a condensing 4th generation

    NASA Astrophysics Data System (ADS)

    Hernández, A. E. Cárcamo; Dib, Claudio O.; Neill, Nicolás A.; Zerwekh, Alfonso R.

    2012-02-01

    We study the hierarchy of quark masses and mixings in a model based on a 5-dimensional spacetime with constant curvature of Randall-Sundrum type with two branes, where the Electroweak Symmetry Breaking is caused dynamically by the condensation of a 4th generation of quarks, due to underlying physics from the 5D bulk and the first KK gluons. We first study the hierarchy of quark masses and mixings that can be obtained from purely adjusting the profile localizations, finding that realistic masses are not reproduced unless non trivial hierarchies of underlying 4-fermion interactions from the bulk are included. Then we study global U(1) symmetries that can be imposed in order to obtain non-symmetric modified Fritzsch-like textures in the mass matrices that reproduce reasonably well quark masses and CKM mixings.

  19. Extracting the flavor dependence of the polarized sea quarks

    NASA Astrophysics Data System (ADS)

    Xu, Qinghua

    2015-10-01

    The measurement of single spin asymmetry AL of W bosons in longitudinally polarized pp collisions at RHIC provides an unique probe for the flavor separation of the nucleon spin structure, especially the polarization of sea quarks. The recent AL results of W bosons from RHIC via leptonic decay provided significant new constraints on the helicity distributions of light sea quarks in addition to constraints from the semi-inclusive deep inelastic scattering data, which also indicated a symmetry breaking between anti-u and anti-d quark polarization in the nucleon. In 2013 the RHIC/STAR experiment collected a proton-proton collision data sample about 3 times larger than the previous data sample. The newest results of AL analysis from RHIC W program and the impact on sea quark polarization will be discussed.

  20. Measurement of the Top Quark Mass Simultaneously in Dilepton and Lepton + Jets Decay Channels

    SciTech Connect

    Fedorko, Wojciech T.

    2008-12-01

    The authors present the first measurement of the top quark mass using simultaneously data from two decay channels. They use a data sample of √s = 1.96 TeV collisions with integrated luminosity of 1.9 fb-1 collected by the CDF II detector. They select dilepton and lepton + jets channel decays of t$\\bar{t}$ pairs and reconstruct two observables in each topology. They use non-parametric techniques to derive probability density functions from simulated signal and background samples. The observables are the reconstructed top quark mass and the scalar sum of transverse energy of the event in the dilepton topology and the reconstructed top quark mass and the invariant mass of jets from the W boson decay in lepton + jets channel. They perform a simultaneous fit for the top quark mass and the jet energy scale which is constrained in situ by the hadronic W boson resonance from the lepton + jets channel. Using 144 dilepton candidate events and 332 lepton + jets candidate events they measure: Mtop = 171.9 ± 1.7 (stat. + JES) ± 1.1 (other sys.) GeV/c2 = 171.9 ± 2.0 GeV/c2. The measurement features a robust treatment of the systematic uncertainties, correlated between the two channels and develops techniques for a future top quark mass measurement simultaneously in all decay channels. Measurements of the W boson mass and the top quark mass provide a constraint on the mass of the yet unobserved Higgs boson. The Higgs boson mass implied by measurement presented here is higher than Higgs boson mass implied by previously published, most precise CDF measurements of the top quark mass in lepton + jets and dilepton channels separately.

  1. Bethe-Salpeter dynamics and the constituent mass concept for heavy quark mesons

    SciTech Connect

    Souchlas, N.; Stratakis, D.

    2010-06-01

    The definition of a quark as heavy requires a comparison of its mass with the nonperturbative chiral symmetry breaking scale which is about 1 GeV ({Lambda}{sub {chi}{approx}1} GeV) or with the scale {Lambda}{sub QCD{approx}}0.2 GeV that characterizes the distinction between perturbative and nonperturbative QCD. For quark masses significantly larger than these scales, nonperturbative dressing effects, or equivalently nonperturbative self-energy contributions, and relativistic effects are believed to be less important for physical observables. We explore the concept of a constituent mass for heavy quarks in the Dyson-Schwinger equations formalism, for light-heavy and heavy-heavy quark mesons by studying their masses and electroweak decay constants.

  2. Measurement of the top quark mass in the dilepton channel at CDF and D0

    SciTech Connect

    Maki, Tuula; /Helsinki U. /Helsinki Inst. of Phys.

    2005-10-01

    We present recent analyses of the top quark mass measurement in dileptonic channel. The measurements use 200-360 pb{sup -1} of data collected by CDF and D0 experiments. The future prospects are discussed as well.

  3. Charm and beauty quark masses in the MMHT2014 global PDF analysis

    NASA Astrophysics Data System (ADS)

    Harland-Lang, L. A.; Martin, A. D.; Motylinski, P.; Thorne, R. S.

    2016-01-01

    We investigate the variation in the MMHT2014 PDFs when we allow the heavy-quark masses m_c and m_b to vary away from their default values. We make PDF sets available in steps of Δ m_c =0.05 GeV and Δ m_b =0.25 GeV, and present the variation in the PDFs and in the predictions. We examine the comparison to the HERA data on charm and beauty structure functions and note that in each case the heavy-quark data, and the inclusive data, have a slight preference for lower masses than our default values. We provide PDF sets with three and four active quark flavours, as well as the standard value of five flavours. We use the pole mass definition of the quark masses, as in the default MMHT2014 analysis, but briefly comment on the overline{MS} definition.

  4. Bethe-Salpeter dynamics and the constituent mass concept for heavy quark mesons

    NASA Astrophysics Data System (ADS)

    Souchlas, N.; Stratakis, D.

    2010-06-01

    The definition of a quark as heavy requires a comparison of its mass with the nonperturbative chiral symmetry breaking scale which is about 1 GeV (Λχ˜1GeV) or with the scale ΛQCD˜0.2GeV that characterizes the distinction between perturbative and nonperturbative QCD. For quark masses significantly larger than these scales, nonperturbative dressing effects, or equivalently nonperturbative self-energy contributions, and relativistic effects are believed to be less important for physical observables. We explore the concept of a constituent mass for heavy quarks in the Dyson-Schwinger equations formalism, for light-heavy and heavy-heavy quark mesons by studying their masses and electroweak decay constants.

  5. STRANGE GOINGS ON IN QUARK MATTER.

    SciTech Connect

    SCHAFER,T.

    2001-06-05

    We review recent work on how the superfluid state of three flavor quark matter is affected by non-zero quark masses and chemical potentials. The study of hadronic matter at high baryon density has recently attracted a lot of interest. At zero baryon density chiral symmetry is broken by a quark-anti-quark condensate. At high density condensation in the quark-anti-quark channel is suppressed. Instead, attractive interactions in the color anti-symmetric quark-quark channel favor the formation of diquark condensates. As a consequence, cold dense quark matter is expected to be a color superconductor. The symmetry breaking pattern depends on the density, the number of quark flavors, and their masses. A particularly symmetric phase is the color-flavor-locked (CFL) phase of three flavor quark matter. This phase is believed to be the true ground state of ordinary matter at very large density.

  6. Dependence of nuclear binding on hadronic mass variation

    SciTech Connect

    Flambaum, V. V.; Wiringa, R. B.

    2007-11-15

    We examine how the binding of light (A{<=}8) nuclei depends on possible variations of hadronic masses, including meson, nucleon, and nucleon-resonance masses. Small variations in hadronic masses may have occurred over time; the present results can help evaluate the consequences for big bang nucleosynthesis. Larger variations may be relevant to current attempts to extrapolate properties of nucleon-nucleon interactions from lattice QCD calculations. Results are presented as derivatives of the energy with respect to the different masses so they can be combined with different predictions of the hadronic mass-dependence on the underlying current-quark mass m{sub q}. As an example, we employ a particular set of relations obtained from a study of hadron masses and sigma terms based on Dyson-Schwinger equations and a Poincare-covariant Faddeev equation for confined quarks and diquarks. We find that nuclear binding decreases moderately rapidly as the quark mass increases, with the deuteron becoming unbound when the pion mass is increased by {approx}60% (corresponding to an increase in X{sub q}=m{sub q}/{lambda}{sub QCD} of 2.5). In the other direction, the dineutron becomes bound if the pion mass is decreased by {approx}15% (corresponding to a reduction of X{sub q} by {approx}30%). If we interpret the disagreement between big bang nucleosynthesis calculations and measurements to be the result of variation in X{sub q}, we obtain an estimate {delta}X{sub q}/X{sub q}=K{center_dot}(0.013{+-}0.002) where K{approx}1 (the expected accuracy in K is about a factor of 2). The result is dominated by {sup 7}Li data.

  7. A precise measurement of the top quark mass in dilepton final states using 9.7 fb$^{-1}$ of D{Ø} Run II data

    SciTech Connect

    Liu, Huanzhao

    2015-05-16

    The top quark is a very special fundamental particle in the Standard Model (SM) mainly due to its heavy mass. The top quark has extremely short lifetime and decays before hadronization. This reduces the complexity for the measurement of its mass. The top quark couples very strongly to the Higgs boson since the fermion-Higgs Yukawa coupling linearly depends on the fermion’s mass. Therefore, the top quark is also heavily involved in Higgs production and related study. A precise measurement of the top quark mass is very important, as it allows for self-consistency check of the SM, and also gives a insight about the stability of our universe in the SM context. This dissertation presents my work on the measurement of the top quark mass in dilepton final states of t$\\bar{t}$ events in p$\\bar{p}$ collisions at √s = 1.96 TeV, using the full DØ Run II data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron. I extracted the top quark mass by reconstructing event kinematics, and integrating over expected neutrino rapidity distributions to obtain solutions over a scanned range of top quark mass hypotheses. The analysis features a comprehensive optimization that I made to minimize the expected statistical uncertainty. I also improve the calibration of jets in dilepton events by using the calibration determined in t$\\bar{t}$ → lepton+jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. The measured mass is 173.11 ± 1.34(stat)+0.83 -0.72(sys) GeV .

  8. Broken S flavor symmetry of leptons and quarks: Mass spectra and flavor mixing patterns

    NASA Astrophysics Data System (ADS)

    Xing, Zhi-zhong; Yang, Deshan; Zhou, Shun

    2010-06-01

    We apply the discrete S3 flavor symmetry to both lepton and quark sectors of the Standard Model extended by introducing one Higgs triplet and realizing the type-II seesaw mechanism for finite neutrino masses. The resultant mass matrices of charged leptons (Ml), neutrinos (Mν), up-type quarks (Mu) and down-type quarks (Md) have a universal form consisting of two terms: one is proportional to the identity matrix I and the other is proportional to the democracy matrix D. We argue that the textures of Ml, Mu and Md are dominated by the D term, while that of Mν is dominated by the I term. This hypothesis implies a near mass degeneracy of three neutrinos and can naturally explain why the mass matrices of charged fermions are strongly hierarchical, why the quark mixing matrix is close to I and why the lepton mixing matrix contains two large angles. We discuss a rather simple perturbation ansatz to break the S3 symmetry and obtain more realistic mass spectra of leptons and quarks as well as their flavor mixing patterns. We stress that the I term, which used to be ignored from Ml, Mu and Md, is actually important because it can significantly modify the smallest lepton flavor mixing angle θ13 or three quark flavor mixing angles.

  9. Top-quark mass measurement using events with missing transverse energy and jets at CDF

    SciTech Connect

    Aaltonen, T.

    2011-11-30

    We present a measurement of the top-quark mass with tt events using a data sample corresponding to an integrated luminosity of 5.7 fb -1 of pp collisions at the Fermilab Tevatron with √s = 1.96 TeV and collected by the CDF II Detector. We select events having no identified charged leptons, large missing transverse energy, and four, five, or six jets with at least one jet containing a secondary vertex consistent with the decay of a b quark. This analysis considers events from the semileptonic tt decay channel, including events that contain tau leptons, which are usually not included in the top-quark mass measurements. The measurement uses as kinematic variables the invariant mass of two jets consistent with the mass of the W boson, and the invariant masses of two different three-jet combinations. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of Mtop = 172.3 ± 2.4 (stat) ± 1.0 (syst) GeV/c2.

  10. Top-quark mass measurement using events with missing transverse energy and jets at CDF

    DOE PAGESBeta

    Aaltonen, T.

    2011-11-30

    We present a measurement of the top-quark mass with tt events using a data sample corresponding to an integrated luminosity of 5.7 fb -1 of pp collisions at the Fermilab Tevatron with √s = 1.96 TeV and collected by the CDF II Detector. We select events having no identified charged leptons, large missing transverse energy, and four, five, or six jets with at least one jet containing a secondary vertex consistent with the decay of a b quark. This analysis considers events from the semileptonic tt decay channel, including events that contain tau leptons, which are usually not included inmore » the top-quark mass measurements. The measurement uses as kinematic variables the invariant mass of two jets consistent with the mass of the W boson, and the invariant masses of two different three-jet combinations. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of Mtop = 172.3 ± 2.4 (stat) ± 1.0 (syst) GeV/c2.« less

  11. Comparing symmetry restoration trends for meson masses and mixing angles in the QCD-like three quark flavor models

    NASA Astrophysics Data System (ADS)

    Tiwari, Vivek Kumar

    2013-10-01

    We are computing the modifications for the scalar and pseudoscalar meson masses and mixing angles due to the proper accounting of fermionic vacuum fluctuation in the framework of the generalized 2+1 flavor quark meson model and the Polyakov loop augmented quark meson model (PQM). The renormalized contribution of the divergent fermionic vacuum fluctuation at one loop level makes these models effective QCD-like models. It has been explicitly shown that analytical expressions for the model parameters, meson masses, and mixing angles do not depend on any arbitrary renormalization scale. We have investigated how the incorporation of fermionic vacuum fluctuation in quark meson and PQM models qualitatively and quantitatively affects the convergence in the masses of the chiral partners in pseudoscalar (π,η,η',K) and scalar (σ,a0,f0,κ) meson nonets as the temperature is varied on the reduced temperature scale. Comparison of present results in the quark meson model with vacuum term and the PQM model with vacuum term with the already existing calculations in the bare 2+1 quark meson and PQM models shows that the restoration of chiral symmetry becomes smoother due to the influence of the fermionic vacuum term. We find that the melting of the strange condensate registers a significant increase in the presence of the fermionic vacuum term and its highest melting is found in the PQM model with vacuum term. The role of the UA(1) anomaly in determining the isoscalar masses and mixing angles for the pseudoscalar (η and η') and scalar (σ and f0) meson complex has also been significantly modified due to the fermionic vacuum correction. In its influence, the interplay of chiral symmetry restoration and the setting up of the UA(1) restoration trends have also been shown to be significantly modified.

  12. Top Quark Mass in Events with two Charged Leptons at the D0 Experiment

    SciTech Connect

    Boline, Daniel Dooley

    2010-01-01

    The top quark is the most massive observed fundamental subatomic particle, and at the Tevatron accelerator is produced mostly in top-antitop (t$\\bar{t}$) quark pairs from the collisions of protons and anti-protons. Each top quark decays into a bottom quark and a W boson. The W boson can then decay into a pair of quarks, or into a charged lepton and a neutrino. The various decays can be broken up into three different channels based on the number of leptons from the decay of the W bosons: all-jets (with no leptons), lepton+jets (with one lepton), and dilepton (with two leptons). This dissertation will present a measurement of the top quark mass in the dilepton channel. The dilepton channel is characterized by two leptons, two neutrinos and two b-quarks. The neutrinos are not directly observed, but their absence is felt as missing transverse momentum (pT) in the detector. The combination of two leptons and large pT produces an easily isolated signal, giving the dilepton channel a high signal over background ratio. Having two neutrinos means that we cannot know what the transverse momenta of either neutrino is. This means that even if we knew the momenta of the leptons and b-quarks perfectly, we would be unable to reconstruct the mass of the top quark. This measurement gets around this problem by scanning over all possible values of the top mass, finding all consistent t{bar t} combinations, assigning a kinematic weight to each, and then adding the weights for each combination at a given possible top mass. The lepton momenta, jet momenta, and pT are only known to within some finite precision, so for a given top mass, I also vary each of these momenta within their resolutions and add the weights for a given possible top mass. After scanning over possible top masses, I choose the top mass with the largest sum of weights mtmax as an observable for the event. I then perform a template based likelihood fit of m

  13. Top quark mass in events with two charged leptons at the D0 experiment

    NASA Astrophysics Data System (ADS)

    Boline, Daniel

    The top quark is the most massive observed fundamental subatomic particle, and at the Tevatron accelerator is produced mostly in top-antitop ( tt¯) quark pairs from the collisions of protons and anti-protons. Each top quark decays into a bottom quark and a W boson. The W boson can then decay into a pair of quarks, or into a charged lepton and a neutrino. The various decays can be broken up into three different channels based on the number of leptons from the decay of the W bosons: all-jets (with no leptons), lepton+jets (with one lepton), and dilepton (with two leptons). This dissertation will present a measurement of the top quark mass in the dilepton channel. The dilepton channel is characterized by two leptons, two neutrinos and two b-quarks. The neutrinos are not directly observed, but their absence is felt as missing transverse momentum ( pT / ) in the detector. The combination of two leptons and large pT / produces an easily isolated signal, giving the dilepton channel a high signal over background ratio. Having two neutrinos means that we cannot know what the transverse momenta of either neutrino is. This means that even if we knew the momenta of the leptons and b-quarks perfectly, we would be unable to reconstruct the mass of the top quark. This measurement gets around this problem by scanning over all possible values of the top mass, finding all consistent tt¯ combinations, assigning a kinematic weight to each, and then adding the weights for each combination at a given possible top mass. The lepton momenta, jet momenta, and pT / are only known to within some finite precision, so for a given top mass, I also vary each of these momenta within their resolutions and add the weights for a given possible top mass. After scanning over possible top masses, I choose the top mass with the largest sum of weights mmaxt as an observable for the event. I then perform a template based likelihood fit of mt using mmaxt . I analyze 322 candidate events collected by the

  14. Mass dependence of nitride sputtering

    NASA Astrophysics Data System (ADS)

    Elovikov, S. S.; Khrustachev, I. K.; Mosunov, A. S.; Yurasova, V. E.

    2003-08-01

    A molecular dynamics simulation was performed to study the sputtering yield Y for BN, AlN and GaN polycrystals of wurtzite structure as a function of the masses m 1 of bombarding ions with energies from 200 to 2000 eV. A nonmonotonic behavior of the Y ( m 1 ) curve was obtained for the irradiation by low-energy ions, the curve having a maximum with a position being dependent on m 2 / m 1 ( m 2 is the average mass of atoms in a compound). For AlN and GaN the maximum was observed at m 2 / m 1 = 2, and for BN at m 2 / m 1 = 1. The effect of the mass of bombarding ions on the mean energies and energy spectra of sputtered particles, the depth of sputtering origin, and the generation of emitted atoms for nitrides was also investigated and discussed.

  15. Bottom-Hadron Mass Splittings from Static-Quark Action on 2+1-Flavor Lattices

    SciTech Connect

    Huey-Wen Lin, Saul D. Cohen, Nilmani Mathur, Kostas Orginos

    2009-09-01

    We calculate bottom-baryon mass splittings using full QCD with 2+1 flavors of dynamical Kogut-Susskind sea quarks and domain-wall valence quarks along with a static heavy quark on a lattice of spatial volume of $(\\sim 2.5\\mbox{ fm})^3$ with lattice spacing of about 0.124~fm over a range of pion masses as low as 291~MeV. We calculate the mass splittings of bottom hadrons with respect to $B_d$ and $\\Lambda_b$. Our results are in agreement with experimental observations and other lattice calculations, within our statistical and systematic errors. In particular, we find the mass of the $\\Omega_b$ to be consistent with the recent CDF measurement. We also predict the mass for the as yet unobserved $\\Xi^\\prime_b$ to be 5955(27)~MeV.

  16. Quark-lepton mass relation in a realistic A4 extension of the Standard Model

    NASA Astrophysics Data System (ADS)

    King, S. F.; Morisi, S.; Peinado, E.; Valle, J. W. F.

    2013-07-01

    We propose a realistic A4 extension of the Standard Model involving a particular quark-lepton mass relation, namely that the ratio of the third family mass to the geometric mean of the first and second family masses are equal for down-type quarks and charged leptons. This relation, which is approximately renormalization group invariant, is usually regarded as arising from the Georgi-Jarlskog relations, but in the present model there is no unification group or supersymmetry. In the neutrino sector we propose a simple modification of the so-called Zee-Wolfenstein mass matrix pattern which allows an acceptable reactor angle along with a deviation of the atmospheric and solar angles from their bi-maximal values. Quark masses, mixing angles and CP violation are well described by a numerical fit.

  17. SUSY Threshold Effects on Quark and Lepton Masses at the GUT Scale

    SciTech Connect

    Antusch, Stefan

    2008-11-23

    We discuss the impact of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the GUT scale within the large tan{beta} regime of the MSSM. In addition to the typically dominant SUSY QCD contributions for the quarks, we also include the electroweak contributions for quarks and leptons which can have significant effects. We provide the GUT scale ranges of quark and charged lepton Yukawa couplings as well as of the ratios m{sub {mu}}/m{sub s}, m{sub e}/m{sub d}, y{sub {tau}}/y{sub b} and y{sub t}/y{sub b} for three example ranges of SUSY parameters and discuss how the enlarged ranges due to threshold effects might open up new possibilities for constructing GUT models of fermion masses and mixings. This is a brief summary of the work of Ref. [1].

  18. Quark and lepton masses at the GUT scale including supersymmetric threshold corrections

    SciTech Connect

    Antusch, S.; Spinrath, M.

    2008-10-01

    We investigate the effect of supersymmetric (SUSY) threshold corrections on the values of the running quark and charged lepton masses at the grand unified theory (GUT) scale within the large tan{beta} regime of the minimal supersymmetric standard model. In addition to the typically dominant SUSY QCD contributions for the quarks, we also include the electroweak contributions for quarks and leptons and show that they can have significant effects. We provide the GUT scale ranges of quark and charged lepton Yukawa couplings as well as of the ratios m{sub {mu}}/m{sub s}, m{sub e}/m{sub d}, y{sub {tau}}/y{sub b} and y{sub t}/y{sub b} for three example ranges of SUSY parameters. We discuss how the enlarged ranges due to threshold effects might open up new possibilities for constructing GUT models of fermion masses and mixings.

  19. Viability of carbon-based life as a function of the light quark mass.

    PubMed

    Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Lee, Dean; Meissner, Ulf-G

    2013-03-15

    The Hoyle state plays a crucial role in the helium burning of stars that have reached the red giant stage. The close proximity of this state to the triple-alpha threshold is needed for the production of carbon, oxygen, and other elements necessary for life. We investigate whether this life-essential condition is robust or delicately fine-tuned by measuring its dependence on the fundamental constants of nature, specifically the light quark mass and the strength of the electromagnetic interaction. We show that there exist strong correlations between the alpha-particle binding energy and the various energies relevant to the triple-alpha process. We derive limits on the variation of these fundamental parameters from the requirement that sufficient amounts of carbon and oxygen be generated in stars. We also discuss the implications of our results for an anthropic view of the Universe. PMID:25166526

  20. Transverse momentum dependent parton distributions in a light-cone quark model

    NASA Astrophysics Data System (ADS)

    Pasquini, B.; Cazzaniga, S.; Boffi, S.

    2008-08-01

    The leading twist transverse momentum dependent parton distributions (TMDs) are studied in a light-cone description of the nucleon where the Fock expansion is truncated to consider only valence quarks. General analytic expressions are derived in terms of the six amplitudes needed to describe the three-quark sector of the nucleon light-cone wave function. Numerical calculations for the T-even TMDs are presented in a light-cone constituent quark model, and the role of the so-called pretzelosity is investigated to produce a nonspherical shape of the nucleon.

  1. Hierarchy and anarchy in quark mass matrices, or can hierarchy tolerate anarchy?

    NASA Astrophysics Data System (ADS)

    Rosenfeld, Rogerio; Rosner, Jonathan L.

    2001-09-01

    The consequences of adding random perturbations (anarchy) to a baseline hierarchical model of quark masses and mixings are explored. Even small perturbations of the order of 5% of the smallest non-zero element can already give deviations significantly affecting parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, so any process generating the anarchy should in general be limited to this order of magnitude. The regularities of quark masses and mixings thus appear to be far from a generic feature of randomness in the mass matrices, and more likely indicate an underlying order.

  2. Cross-section-constrained top-quark mass measurement from dilepton events at the Tevatron.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; DeCecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

    2008-02-15

    We report the first top-quark mass measurement that uses a cross-section constraint to improve the mass determination. This measurement is made with a dilepton tt event candidate sample collected with the Collider Detector II at Fermilab. From a data sample corresponding to an integrated luminosity of 1.2 fb(-1), we measure a top-quark mass of 170.7(-3.9)(+4.2)(stat)+/-2.6(syst)+/-2.4(theory) GeV/c(2). The measurement without the cross-section constraint is 169.7(-4.9)(+5.2)(stat)+/-3.1(syst) GeV/c(2). PMID:18352461

  3. Determination of the top-quark pole mass using tt¯ + 1-jet events collected with the ATLAS experiment in 7TeV pp collisions

    SciTech Connect

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balestri, T.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansil, H. S.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J. -B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.; Bugge, M. K.; Bulekov, O.

    2015-10-19

    In this study, the normalized differential cross section for top-quark pair production in association with at least one jet is studied as a function of the inverse of the invariant mass of the tt¯ + 1-jet system. This distribution can be used for a precise determination of the top-quark mass since gluon radiation depends on the mass of the quarks. The experimental analysis is based on proton-proton collision data collected by the ATLAS detector at the LHC with a centre-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.6 fb–1 . The selected events were identified using the lepton+jets top-quark-pair decay channel, where lepton refers to either an electron or a muon. The observed distribution is compared to a theoretical prediction at next-to-leading-order accuracy in quantum chromodynamics using the pole-mass scheme. With this method, the measured value of the top-quark pole mass, mpolet , is: mpolet = 173.7 ± 1.5(stat.) ± 1.4(syst.)+1.0–0.5(theory) GeV.

  4. Determination of the top-quark pole mass using tt¯ + 1-jet events collected with the ATLAS experiment in 7TeV pp collisions

    DOE PAGESBeta

    Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; et al

    2015-10-19

    In this study, the normalized differential cross section for top-quark pair production in association with at least one jet is studied as a function of the inverse of the invariant mass of the tt¯ + 1-jet system. This distribution can be used for a precise determination of the top-quark mass since gluon radiation depends on the mass of the quarks. The experimental analysis is based on proton-proton collision data collected by the ATLAS detector at the LHC with a centre-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.6 fb–1 . The selected events were identified using themore » lepton+jets top-quark-pair decay channel, where lepton refers to either an electron or a muon. The observed distribution is compared to a theoretical prediction at next-to-leading-order accuracy in quantum chromodynamics using the pole-mass scheme. With this method, the measured value of the top-quark pole mass, mpolet , is: mpolet = 173.7 ± 1.5(stat.) ± 1.4(syst.)+1.0–0.5(theory) GeV.« less

  5. First results from $2+1$ dynamical quark flavors on an anisotropic lattice: light-hadron spectroscopy and setting the strange-quark mass

    SciTech Connect

    Lin, Huey-Wen; Cohen, Saul; Dudek, Jozef; Edwards, Robert; Joo, Balint; Richards, David; Bulava, John; Foley, Justin; Morningstar, Colin; Engelson, Eric; Wallace, Stephen; Juge, Jimmy; Mathur, Nilmani; Peardon, Michael; Ryan, Sinead

    2009-02-01

    We present the first light-hadron spectroscopy on a set of $N_f=2+1$ dynamical, anisotropic lattices. A convenient set of coordinates that parameterize the two-dimensional plane of light and strange-quark masses is introduced. These coordinates are used to extrapolate data obtained at the simulated values of the quark masses to the physical light and strange-quark point. A measurement of the Sommer scale on these ensembles is made and the performance of the hybrid Monte Carlo algorithm used for generating the ensembles is estimated.

  6. Measurement of the top-quark mass with dilepton events selected using neuroevolution at CDF.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzurri, P; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Beringer, J; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Calancha, C; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Copic, K; Cordelli, M; Cortiana, G; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lorenzo, G; Dell'orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Derwent, P F; di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Elagin, A; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Gessler, A; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhr, T; Kulkarni, N P; Kurata, M; Kusakabe, Y; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, E; Lee, S W; Leone, S; Lewis, J D; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Merkel, P; Mesropian, C; Miao, T; Miladinovic, N; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moggi, N; Moon, C S; Moore, R; Morello, M J; Morlok, J; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shears, T; Shekhar, R; Shepard, P F; Sherman, D; Shimojima, M; Shiraishi, S; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Tourneur, S; Tu, Y; Turini, N; Ukegawa, F; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Whiteson, S; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Xie, S; Yagil, A; Yamamoto, K; Yamaoka, J; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

    2009-04-17

    We report a measurement of the top-quark mass M_{t} in the dilepton decay channel tt[over ] --> bl;{'+} nu_{l};{'}b[over ]l;{-}nu[over ]_{l}. Events are selected with a neural network which has been directly optimized for statistical precision in top-quark mass using neuroevolution, a technique modeled on biological evolution. The top-quark mass is extracted from per-event probability densities that are formed by the convolution of leading order matrix elements and detector resolution functions. The joint probability is the product of the probability densities from 344 candidate events in 2.0 fb;{-1} of pp[over ] collisions collected with the CDF II detector, yielding a measurement of M_{t} = 171.2 +/- 2.7(stat) +/- 2.9(syst) GeV / c;{2}. PMID:19518620

  7. Measurement of the top quark mass in lepton+jets events with secondary vertex tagging

    SciTech Connect

    Harrington, Robert Duane; /Northeastern U.

    2007-02-01

    A measurement of the top quark mass with the matrix element method in the lepton + jets final state in D0 Run II is presented. Events with single isolated energetic charged lepton (electron or muon), exactly four calorimeter jets, and significant missing transverse energy are selected. Probabilities used to discriminate between signal and background are assumed to be proportional to differential cross-sections, calculated using event kinematics and folding in object resolutions and parton distribution functions. The event likelihoods constructed using these probabilities are varied with the top quark mass, m{sub t}, and the jet energy scale, JES, to give the smallest possible combined statistical + JES uncertainty.

  8. Unitarity triangle and quark mass matrices on the nearest-neighbor interaction basis

    NASA Astrophysics Data System (ADS)

    Ito, Toshiaki; Tanimoto, Morimitsu

    1997-02-01

    We examine the unitarity triangle of the KM matrix, which is derived from the general quark mass matrices in the NNI basis. The Fritzsch Ansätze are modified by introducing four additional parameters. The KM matrix elements are expressed in terms of quark mass ratios, two phases, and four additional parameters. It is found that the vertex of the unitarity triangle is predicted to be almost in the second quadrant on the ρ-η plane as far as Vus~=-md/mseip+mu/mceiq.

  9. New GUT predictions for quark and lepton mass ratios confronted with phenomenology

    SciTech Connect

    Antusch, S.; Spinrath, M.

    2009-05-01

    Group theoretical factors from grand unified theory (GUT) symmetry breaking can lead to predictions for the ratios of quark and lepton masses (or Yukawa couplings) at the unification scale. Because of supersymmetric (SUSY) threshold corrections the viability of such predictions can depend strongly on the SUSY parameters. For three common minimal SUSY breaking scenarios with anomaly, gauge, and gravity mediation we investigate which GUT scale ratios m{sub e}/m{sub d}, m{sub {mu}}/m{sub s}, y{sub {tau}}/y{sub b}, and y{sub t}/y{sub b} are allowed when phenomenological constraints from electroweak precision observables, B physics, (g-2){sub {mu}}, mass limits on sparticles from direct searches as well as, optionally, dark matter constraints are taken into account. We derive possible new predictions for the GUT scale mass ratios and compare them with the phenomenologically allowed ranges. We find that new GUT scale predictions such as m{sub {mu}}/m{sub s}=9/2 or 6 and y{sub {tau}}/y{sub b}=3/2 or 2 are often favored compared to the ubiquitous relations m{sub {mu}}/m{sub s}=3 or y{sub {tau}}/y{sub b}=1. They are viable for characteristic SUSY scenarios, testable at the CERN LHC and future colliders.

  10. Quark pseudoscalar vertex and quark mass function with clover fermions: Spontaneous symmetry breaking, operator product expansion, symmetry restoration at small volume

    SciTech Connect

    Boucaud, Ph.; Leroy, J.-P.; Le Yaouanc, A.; Micheli, J.; Pene, O.; Rodriguez-Quintero, J.

    2010-05-01

    We study the quark mass function on hypercubic lattices in a large range of physical volumes and cutoffs. To avoid the very large Wilson term artefact, we exploit the relation between the quark mass function and the pseudoscalar vertex in the continuum. We extrapolate to the chiral limit. In function of the physical volume, we observe a striking discontinuity in the properties of chiral extrapolation around a physical volume L{sub c{approx_equal}}6 GeV{sup -1}=1.2 fm. It is present in the quark mass function, which collapses to zero, as well as in the pion mass and the quark condensate as directly calculated from the pseudoscalar correlator. It is strongly reminiscent of the phenomenon of chiral symmetry restoration observed by Neuberger and Narayanan at N{sub C}={infinity} around the same physical length. In the case of spontaneous symmetry breaking, we confirm that the operator product expansion of the quark mass function, involving the quark condensate, is not operative at the available momenta, even taking into account the unusually large high order corrections to the Wilson coefficient calculated by Chetyrkin and Maier; the gap remains large, around a factor 2, even at the largest momenta available to us (p{approx_equal}6 GeV).

  11. Measurements of the Top Quark Mass in the Dilepton Decay Channel at the D0 Experiment

    SciTech Connect

    Grohsjean, Alexander

    2008-10-01

    We present the most recent measurements of the top quark mass in the dilepton decay channel at the D0 experiment using proton-antiproton collisions with a center-of-mass energy of 1.96 TeV at the Tevatron collider. Two different methods have been used: the Neutrino Weighting and the Matrix Element method. The combined results yield a top mass of 174.4 +-3.8 GeV.

  12. Estimating the unquenched strange quark mass from the lattice axial Ward identity

    SciTech Connect

    Goeckeler, M.; Horsley, R.; Zanotti, J.M.; Irving, A.C.; Rakow, P.E.L.; Pleiter, D.; Schierholz, G.; Stueben, H.

    2006-03-01

    We present a determination of the strange quark mass for two flavors (n{sub f}=2) of light dynamical quarks using the axial Ward identity. The calculations are performed on the lattice using O(a) improved Wilson fermions and include a fully nonperturbative determination of the renormalization constant. In the continuum limit we find m{sub s}{sup MS}(2 GeV)=111(6)(4)(6) MeV, using the force scale r{sub 0}=0.467 fm, where the first error is statistical, the second and third are systematic due to the fit and scale uncertainties, respectively. Results are also presented for the light quark mass and the chiral condensate. The corresponding results are also given for r{sub 0}=0.5 fm.

  13. D0 top quark results and their dependence on successful grid computing

    SciTech Connect

    Wicke, Daniel; /Fermilab

    2005-07-01

    The heaviest known Fermion particle--the top quark--was discovered at Fermilab in the first run of the Tevatron in 1995. However, besides its mere existence one needs to study its properties precisely in order to verify or falsify the predictions of the Standard Model. With the top quark's extremely high mass and short lifetime such measurements probe yet unexplored regions of the theory and bring us closer to solving the open fundamental questions of our universe of elementary particles such as why three families of quarks and leptons exist and why their masses differ so dramatically. To perform these measurements hundreds of millions of recorded proton-antiproton collisions must be reconstructed and filtered to extract the few top quarks produced. Simulated background and signal events with full detector response need to be generated and reconstructed to validate and understand the results. Since the start of the second run of the Tevatron the D0 collaboration has brought Grid computing to its aid for the production of simulated events. Data processing on the Grid has recently been added and thereby enabled us to effectively triple the amount of data available with the highest quality reconstruction methods. We will present recent top quark results D0 obtained from these improved data and explain how they benefited from the availability of computing resources on the Grid.

  14. Confinement, quark mass functions, and spontaneous chiral symmetry breaking in Minkowski space

    SciTech Connect

    Biernat, Elmar P.; Gross, Franz L.; Pena, Teresa; Stadler, Alfred

    2014-01-01

    We formulate the covariant equations for quark-antiquark bound states in Minkowski space in the framework of the Covariant Spectator Theory. The quark propagators are dressed with the same kernel that describes the interaction between different quarks. We show that these equations are charge conjugation invariant, and that in the chiral limit of vanishing bare quark mass, a massless pseudoscalar bound state is produced in a Nambu--Jona-Lasinio (NJL) mechanism, which is associated with the Goldstone boson of spontaneous chiral symmetry breaking. In this introductory paper we test the formalism by using a simplified kernel consisting of a momentum-space $\\delta$-function with a vector Lorentz structure, to which one adds a mixed scalar and vector confining interaction. The scalar part of the confining interaction is not chirally invariant by itself, but decouples from the equations in the chiral limit and therefore allows the NJL mechanism to work. With this model we calculate the quark mass function, and we compare our Minkowski-space results to LQCD data obtained in Euclidean space. In a companion paper we apply this formalism to a calculation of the pion form factor.

  15. PQChPT with Staggered Sea and Valence Ginsparg-Wilson Quarks: Vector Meson Masses

    SciTech Connect

    Hovhannes R. Grigoryan; Anthony W. Thomas

    2005-09-16

    We consider partially quenched, mixed chiral perturbation theory with staggered sea and Ginsparg-Wilson valence quarks in order to extract a chiral-continuum extrapolation expression for the vector meson mass up to order O(a{sup 2}), at one-loop level. Based on general principles, we accomplish the task without explicitly constructing a sophisticated, heavy vector meson chiral Lagrangian.

  16. A measurement of the mass of the top quark using the ideogram technique

    SciTech Connect

    Houben, Pieter Willem Huib

    2009-06-03

    This thesis describes a measurement of the mass of the top quark on data collected with the D0 detector at the Tevatron collider in the period from 2002 until 2006. The first chapter describes the Standard Model and the prominent role of the top quark mass. The second chapter gives a description of the D0 detector which is used for this measurement. After the p$\\bar{p}$ collisions have been recorded, reconstruction of physics objects is required, which is described in Chapter 3. Chapter 4 describes how the interesting collisions in which top quarks are produced are separated from the `uninteresting' ones with a set of selection criteria. The method to extract the top quark mass from the sample of selected collisions (also called events), which is based on the ideogram technique, is explained in Chapter 5, followed in Chapter 6 by the description of the calibration of the method using simulation of our most precise knowledge of nature. Chapter 7 shows the result of the measurement together with some cross checks and an estimation of the uncertainty on this measurement. This thesis concludes with a constraint on the Higgs boson mass.

  17. Heavy-Quark Mass and Heavy-Meson Decay Constants from QCD Sum Rules

    SciTech Connect

    Lucha, Wolfgang; Melikhov, Dmitri; Simula, Silvano

    2011-05-23

    We present a sum-rule extraction of decay constants of heavy mesons from the two-point correlator of heavy-light pseudoscalar currents. Our primary concern is to control the uncertainties of the decay constants, induced by both input QCD parameters and limited accuracy of the sum-rule method. Gaining this control is possible by applying our novel procedure for the extraction of hadron observables utilizing Borel-parameter-depending dual thresholds. For the charmed mesons, we obtain f{sub D} (206.2{+-}7.3{sub (OPE){+-}}5.1{sub (syst)}) MeV and f{sub D{sub s}} (245.3{+-}15.7{sub (OPE){+-}}4.5{sub (syst)}) MeV. In the case of the beauty mesons, the decay constants prove to be extremely sensitive to the exact value of the b-quark MS mass m-bar{sub b}(m-bar{sub b}). By matching our sum-rule prediction for f{sub B} to the lattice outcomes, the very accurate b-mass value m-bar{sub b}(m-bar{sub b}) = (4.245{+-}0.025) GeV is found, which yields f{sub B} = (193.4{+-}12.3{sub (OPE){+-}}4.3{sub (syst)}) MeV and f{sub B{sub s}} (232.5{+-}18.6{sub (OPE){+-}}2.4{sub (syst)}) MeV.

  18. Precision measurement of the top-quark mass in lepton+jets final states

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2014-07-17

    We measure the mass of the top quark in lepton$+$jets final states using the full sample of $p\\bar{p}$ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at $\\sqrt s=1.96 $TeV, corresponding to $9.7 {\\rm fb}^{-1}$ of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from $t\\bar t$ production or background. The overall jet energy scale is constrained in situ by the mass of the $W$ boson. We measure $m_t=174.98\\pm0.76$ GeV. In conclusion, this constitutes the most precise single measurement of the top-quark mass.

  19. Precision measurement of the top-quark mass in lepton+jets final states

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2014-07-17

    We measure the mass of the top quark in leptonmore » $+$jets final states using the full sample of $$p\\bar{p}$$ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at $$\\sqrt s=1.96 $$TeV, corresponding to $$9.7 {\\rm fb}^{-1}$$ of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from $$t\\bar t$$ production or background. The overall jet energy scale is constrained in situ by the mass of the $W$ boson. We measure $$m_t=174.98\\pm0.76$$ GeV. In conclusion, this constitutes the most precise single measurement of the top-quark mass.« less

  20. Precision measurement of the top-quark mass in lepton$+$jets final states

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2015-06-04

    We measure the mass of the top quark in lepton þ jets final states using the full sample of pp¯ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at √s = 1.96 TeV, corresponding to 9.7 fb-1 of integrated luminosity. We also use a matrix element technique that calculates the probabilities for each event to result from tt¯ production or background. Furthermore, the overall jet energy scale is constrained in situ by the mass of the W boson. We measure mt = 174.98 ± 0.76 GeV. As a result, this constitutes the mostmore » precise single measurement of the top-quark mass.« less

  1. Precision measurement of the top quark mass in lepton + jets final States.

    PubMed

    Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Askew, A; Atkins, S; Augsten, K; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Bartlett, J F; Bassler, U; Bazterra, V; Bean, A; Begalli, M; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Borysova, M; Brandt, A; Brandt, O; Brock, R; Bross, A; Brown, D; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Buszello, C P; Camacho-Pérez, E; Casey, B C K; Castilla-Valdez, H; Caughron, S; Chakrabarti, S; Chan, K M; Chandra, A; Chapon, E; Chen, G; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Das, A; Davies, G; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Ding, P F; Dominguez, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, V N; Fauré, A; Feng, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Gavrilov, V; Geng, W; Gerber, C E; Gershtein, Y; Ginther, G; Gogota, O; Golovanov, G; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Gutierrez, G; Gutierrez, P; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hogan, J; Hohlfeld, M; Holzbauer, J L; Howley, I; Hubacek, Z; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jayasinghe, A; Jeong, M S; Jesik, R; Jiang, P; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kajfasz, E; Karmanov, D; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kiselevich, I; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Lammers, S; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, H; Liu, Y; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Mansour, J; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Mulhearn, M; Nagy, E; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Nguyen, H T; Nunnemann, T; Orduna, J; Osman, N; Osta, J; Pal, A; Parashar, N; Parihar, V; Park, S K; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Pleier, M-A; Podstavkov, V M; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santos, A S; Savage, G; Savitskyi, M; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shaw, S; Shchukin, A A; Simak, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stoyanova, D A; Strauss, M; Suter, L; Svoisky, P; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verkheev, A Y; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yamada, R; Yang, S; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J M; Zennamo, J; Zhao, T G; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2014-07-18

    We measure the mass of the top quark in lepton+jets final states using the full sample of pp collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at sqrt[s] = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from tt production or background. The overall jet energy scale is constrained in situ by the mass of the W boson. We measure m(t) = 174.98 ± 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass. PMID:25083634

  2. Precision measurement of the top-quark mass in lepton$+$jets final states

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2015-06-04

    We measure the mass of the top quark in lepton þ jets final states using the full sample of pp¯ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at √s = 1.96 TeV, corresponding to 9.7 fb-1 of integrated luminosity. We also use a matrix element technique that calculates the probabilities for each event to result from tt¯ production or background. Furthermore, the overall jet energy scale is constrained in situ by the mass of the W boson. We measure mt = 174.98 ± 0.76 GeV. As a result, this constitutes the most precise single measurement of the top-quark mass.

  3. Measurement of the top quark mass using the matrix element technique in dilepton final states

    DOE PAGESBeta

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; et al

    2016-08-18

    Here, we present a measurement of the top quark mass in pp collisions at a center-of-mass energy of 1.96 TeV at the Fermilab Tevatron collider. The data were collected by the D0 experiment corresponding to an integrated luminosity of 9.7 fb-1. The matrix element technique is applied to tt events in the final state containing leptons (electrons or muons) with high transverse momenta and at least two jets. The calibration of the jet energy scale determined in the lepton+jets final state of tt decays is applied to jet energies. This correction provides a substantial reduction in systematic uncertainties. We obtain amore » top quark mass of mt = 173.93±1.84 GeV.« less

  4. Measurement of the top quark mass in the all hadronic final state at the D0 experiment

    SciTech Connect

    Jayasinghe, Ayesh

    2013-01-01

    The top quark is the heaviest fermion observed to date. A precise measurement of its mass and W boson mass is important to indirect measurements of Higgs boson mass. Furthermore, the top quark mass, W boson mass and Higgs boson mass may test the Standard Model using the correlations between them. Here in this thesis, we present a measurement of the top quark mass in the all hadronic final state using the template method. This final state has the advantage of being fully reconstructed in the detector and having the largest branching fraction. The measurement is performed on 4033 candidate events collected using the DØ detector. The data is collected from pp collisions generated at √s =1.96 GeV by the TEVATRON accelerator, Fermi National Accelerator Laboratory, Batavia IL. This is a two dimensional measurement formulated to extract the top quark mass as well as lower the systematic uncertainty due to the jet energy scale calibration. A kinematic fitter is employed to build the templates of signal and background for various input top quark mass points and jet energy scale variations. These templates are compared to data to obtain the fitted top quark mass, jet energy scale shift and their uncertainties.

  5. Transverse-momentum-dependent quark splitting functions in k T -factorization: real contributions

    NASA Astrophysics Data System (ADS)

    Gituliar, Oleksandr; Hentschinski, Martin; Kutak, Krzysztof

    2016-01-01

    We calculate transverse momentum dependent quark splitting kernels P gq and P qq within k T -factorization, completing earlier results which concentrated on gluon splitting functions P gg and P qg . The complete set of splitting kernels is an essential requirement for the formulation of a complete set of evolution equations for transverse momentum dependent parton distribution functions and the development of corresponding parton shower algorithms.

  6. Up and Down Quark Masses and Corrections to Dashen's Theorem from Lattice QCD and Quenched QED.

    PubMed

    Fodor, Z; Hoelbling, C; Krieg, S; Lellouch, L; Lippert, Th; Portelli, A; Sastre, A; Szabo, K K; Varnhorst, L

    2016-08-19

    In a previous Letter [Borsanyi et al., Phys. Rev. Lett. 111, 252001 (2013)] we determined the isospin mass splittings of the baryon octet from a lattice calculation based on N_{f}=2+1 QCD simulations to which QED effects have been added in a partially quenched setup. Using the same data we determine here the corrections to Dashen's theorem and the individual up and down quark masses. Our ensembles include 5 lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and average up-down quark masses all the way down to their physical value. For the parameter which quantifies violations to Dashen's theorem, we obtain ϵ=0.73(2)(5)(17), where the first error is statistical, the second is systematic, and the third is an estimate of the QED quenching error. For the light quark masses we obtain, m_{u}=2.27(6)(5)(4) and m_{d}=4.67(6)(5)(4)  MeV in the modified minimal subtraction scheme at 2  GeV and the isospin breaking ratios m_{u}/m_{d}=0.485(11)(8)(14), R=38.2(1.1)(0.8)(1.4), and Q=23.4(0.4)(0.3)(0.4). Our results exclude the m_{u}=0 solution to the strong CP problem by more than 24 standard deviations. PMID:27588847

  7. Up and Down Quark Masses and Corrections to Dashen's Theorem from Lattice QCD and Quenched QED

    NASA Astrophysics Data System (ADS)

    Fodor, Z.; Hoelbling, C.; Krieg, S.; Lellouch, L.; Lippert, Th.; Portelli, A.; Sastre, A.; Szabo, K. K.; Varnhorst, L.; Budapest-Marseille-Wuppertal Collaboration

    2016-08-01

    In a previous Letter [Borsanyi et al., Phys. Rev. Lett. 111, 252001 (2013)] we determined the isospin mass splittings of the baryon octet from a lattice calculation based on Nf=2 +1 QCD simulations to which QED effects have been added in a partially quenched setup. Using the same data we determine here the corrections to Dashen's theorem and the individual up and down quark masses. Our ensembles include 5 lattice spacings down to 0.054 fm, lattice sizes up to 6 fm, and average up-down quark masses all the way down to their physical value. For the parameter which quantifies violations to Dashen's theorem, we obtain ɛ =0.73 (2 )(5 )(17 ), where the first error is statistical, the second is systematic, and the third is an estimate of the QED quenching error. For the light quark masses we obtain, mu=2.27 (6 )(5 )(4 ) and md=4.67 (6 )(5 )(4 ) MeV in the modified minimal subtraction scheme at 2 G e V and the isospin breaking ratios mu/md=0.485 (11 )(8 )(14 ), R =38.2 (1.1 )(0.8 )(1.4 ), and Q =23.4 (0.4 )(0.3 )(0.4 ). Our results exclude the mu=0 solution to the strong C P problem by more than 24 standard deviations.

  8. A measurement of the top quark mass with a matrix element method

    SciTech Connect

    Gibson, Adam Paul; /UC, Berkeley

    2006-12-01

    The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb{sup -1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t{bar t} and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb{sup -1} dataset they extract a top quark mass of 172.0 {+-} 2.6(stat) {+-} 3.3(syst) GeV/c{sup 2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c{sup 2} for m{sub t} = 178 GTeV/c{sup 2} and 3.1 GeV/c{sup 2} for m{sub t} = 172.5 GeV/c{sup 2}. The systematic error is dominated by the uncertainty of the jet energy scale.

  9. CHIRAL LIMIT AND LIGHT QUARK MASSES IN 2+1 FLAVOR DOMAIN WALL QCD.

    SciTech Connect

    SCHOLZ,E.; LIN, M.

    2007-07-30

    We present results for meson masses and decay constants measured on 24{sup 3} x 64 lattices using the domain wall fermion formulation with an extension of the fifth dimension of L{sub s} = 16 for N{sub f} 2 + 1 dynamical quark flavors. The lightest dynamical meson mass in our set-up is around 331MeV. while partially quenched mesons reach masses as low as 250MeV. The applicability of SU(3) x SU(3) and SU(2) x SU(2) (partially quenched) chiral perturbation theory will be compared and we quote values for the low-energy constants from both approaches. We will extract the average light quark and strange quark masses and use a non-perturbative renormalization technique (RI/MOM) to quote their physical values. The pion and kaon decay constants are determined at those values from our chiral fits and their ratio is used to obtain the CKM-matrix element |V{sub us}|. The results presented here include statistical errors only.

  10. Quark masses, chiral symmetry, and the U(1) anomaly

    SciTech Connect

    Creutz, M.

    1996-09-17

    The author discusses the mass parameters appearing in the gauge theory of the strong interactions, concentrating on the two flavor case. He shows how the effect of the CP violating parameter {theta} is simply interpreted in terms of the state of the aether via an effective potential for meson fields. For degenerate flavors he shows that a first order phase transition is expected at {theta} = {pi}. The author speculates on the implications of this structure for Wilson`s lattice fermions.

  11. Measurement of the Top Quark Mass at CDF Using the Template Method in the Lepton + Jets Channel

    SciTech Connect

    Adelman, Jahred A.

    2008-06-01

    A measurement of the top quark mass in p$\\bar{p}$ collisions at √s = 1.96 TeV is presented. The analysis uses a template method, in which the overconstrained kinematics of the Lepton+Jets channel of the t$\\bar{t}$ system are used to measure a single quantity, the reconstructed top quark mass, that is strongly correlated with the true top quark mass. in addition, the dijet mass of the hadronically decaying W boson is used to constrain in situ the uncertain jet energy scale in the CDF detector. Two-dimensional probability density functions are derived using a kernel density estimate-based machinery. Using 1.9 fb-1 of data, the top quark mass is measured to be 171.8$+1.9\\atop{-1.9}$(stat.) ± 1.0(syst.)GeV/c2.

  12. Precise measurement of the top-quark mass in the lepton+jets topology at CDF II.

    PubMed

    Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carrillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vazquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-11-01

    We present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. We analyze events from the single lepton plus jets final state (tt-->W(+)bW(-)b-->lnubqq'b). The top-quark mass is extracted using a direct calculation of the probability density that each event corresponds to the tt final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb(-1) of integrated luminosity, we achieve the single most precise measurement of the top-quark mass, 170.8+/-2.2(stat.)+/-1.4(syst.) GeV/c(2). PMID:17995397

  13. On the computation of finite bottom-quark mass effects in Higgs boson production

    NASA Astrophysics Data System (ADS)

    Mueller, Romain; Öztürk, Deniz Gizem

    2016-08-01

    We present analytic results for the partonic cross-sections contributing to the top-bottom interference in Higgs production via gluon fusion at hadron colliders at NLO accuracy in QCD. We develop a method of expansion in small bottom-mass for master integrals and combine it with the usual infinite top-mass effective theory. Our method of expansion admits a simple algorithmic description and can be easily generalized to any small parameter. These results for the integrated cross-sections will be needed in the computation of the renormalization counter-terms entering the computation of finite bottom-quark mass effects at NNLO.

  14. Measurement of the Top Quark Mass in the Lepton+Jets Channel Using the Lepton Transverse Momentum

    SciTech Connect

    Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; /Purdue U. /Waseda U. /Dubna, JINR

    2011-01-01

    This letter reports a measurement of the top quark mass, M{sub top}, in data from p{bar p} collisions at {radical}s = 1.96 TeV corresponding to 2.7 fb{sup -1} of integrated luminosity at the Fermilab Tevatron using the CDF II detector. Events with the lepton+jets topology are selected. An unbinned likelihood is constructed based on the dependence of the lepton transverse momentum, P{sub T}, on M{sub top}. A maximum likelihood fit to the data yields a measured mass M{sub top} = 176.9 {+-} 8.0{sub stat} {+-} 2.7{sub syst} GeV/c{sup 2}. In this measurement, the contribution by the jet energy scale uncertainty to the systematic error is negligible. The result provides an important consistency test for other M{sub top} measurements where explicit use of the jet energy is made for deriving the top quark mass.

  15. Precise MS light-quark masses from lattice QCD in the regularization invariant symmetric momentum-subtraction scheme

    SciTech Connect

    Gorbahn, Martin; Jaeger, Sebastian

    2010-12-01

    We compute the conversion factors needed to obtain the MS and renormalization-group-invariant (RGI) up, down, and strange quark masses at next-to-next-to-leading order from the corresponding parameters renormalized in the recently proposed RI/SMOM and RI/SMOM{sub {gamma}{sub {mu}} }renormalization schemes. This is important for obtaining the MS masses with the best possible precision from numerical lattice QCD simulations, because the customary RI{sup (')}/MOM scheme is afflicted with large irreducible uncertainties both on the lattice and in perturbation theory. We find that the smallness of the known one-loop matching coefficients is accompanied by even smaller two-loop contributions. From a study of residual scale dependences, we estimate the resulting perturbative uncertainty on the light-quark masses to be about 2% in the RI/SMOM scheme and about 3% in the RI/SMOM{sub {gamma}{sub {mu}} }scheme. Our conversion factors are given in fully analytic form, for general covariant gauge and renormalization point. We provide expressions for the associated anomalous dimensions.

  16. Precision Measurement of the Mass of the Top Quark in p anti-p Collisions

    SciTech Connect

    Garcia, Carlos A.; /Rochester U.

    2007-01-01

    We report a measurement of the mass of the top quark (m{sub top}) in p{bar p} collisions at a center of mass energy of 1.96 TeV. The analysis is based on p{bar p}{yields}t{bar t}{yields} lepton+jets data recorded with the D0 detector at the Fermilab Tevatron Collider. Events were preselected in the e+jets (913 events/pb of data) and in the {mu}+jets (871 events/pb of data) channels. These were analyzed through a comparison of the matrix element for the production and decay of the t{bar t} states with data, using a likelihood method and 'tagged' b quarks from the t {yields} Wb decays.

  17. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    SciTech Connect

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  18. Precise measurement of the top quark mass in dilepton decays using optimized neutrino weighting

    DOE PAGESBeta

    Abazov, Victor Mukhamedovich

    2015-11-11

    We measure the top quark mass in dilepton final states of tt¯ events in pp¯ collisions at √s= 1.96 TeV, using data corresponding to an integrated luminosity of 9.7 fb-1 at the Fermilab Tevatron Collider. The analysis features a comprehensive optimization of the neutrino weighting method to minimize the statistical uncertainties. Furthermore, we improve the calibration of jet energies using the calibration determined in tt¯ → lepton + jets events, which reduces the otherwise limiting systematic uncertainty from the jet energy scale. As a result, the measured top quark mass is mt = 173.32±1.36(stat)±0.85(syst) GeV.

  19. Calibration of the Top-Quark Monte Carlo Mass.

    PubMed

    Kieseler, Jan; Lipka, Katerina; Moch, Sven-Olaf

    2016-04-22

    We present a method to establish, experimentally, the relation between the top-quark mass m_{t}^{MC} as implemented in Monte Carlo generators and the Lagrangian mass parameter m_{t} in a theoretically well-defined renormalization scheme. We propose a simultaneous fit of m_{t}^{MC} and an observable sensitive to m_{t}, which does not rely on any prior assumptions about the relation between m_{t} and m_{t}^{MC}. The measured observable is independent of m_{t}^{MC} and can be used subsequently for a determination of m_{t}. The analysis strategy is illustrated with examples for the extraction of m_{t} from inclusive and differential cross sections for hadroproduction of top quarks. PMID:27152794

  20. The First measurement of the top quark mass at CDF II in the lepton+jets and dilepton channels simultaneously

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Albrow, Michael G.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, J.; Apollinari, G.; /Fermilab /Purdue U.

    2008-09-01

    The authors present a measurement of the mass of the top quark using data corresponding to an integrated luminosity of 1.9 fb{sup -1} of p{bar p} collisions collected at {radical}s = 1.96 TeV with the CDF II detector at Fermilab's Tevatron. This is the first measurement of the top quark mass using top-antitop pair candidate events in the lepton + jets and dilepton decay channels simultaneously. They reconstruct two observables in each channel and use a non-parametric kernel density estimation technique to derive two-dimensional probability density functions from simulated signal and background samples. The observables are the top quark mass and the invariant mass of two jets from the W decay in the lepton + jets channel, and the top quark mass and the scalar sum of transverse energy of the event in the diletpon channel. They perform a simultaneous fit for the top quark mass and the jet energy scale, which is constrained in situ by the hadronic W boson mass. using 332 lepton + jets candidate events and 144 diletpon candidate events, they measure the top quark mass to be m{sub top} = 171.9 {+-} 1.7 (stat. + JES) {+-} 1.1 (other sys.) GeV/c{sup 2} = 171.9 {+-} 2.0 GeV/c{sup 2}.

  1. Quark masses, B-parameters, and CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon}

    SciTech Connect

    Gupta, R.

    1998-01-20

    After a brief introduction to lattice QCD, the author summarizes the results for the light quark masses and the bag parameters B{sub K}, B{sub 6}{sup 1/2}, and B{sub 8}{sup 3/2}. The implications of these results for the standard model estimates of CP violation parameters {epsilon} and {epsilon}{prime}/{epsilon} are also discussed.

  2. Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation

    SciTech Connect

    Hrayr Matevosyan; Anthony Thomas; Peter Tandy

    2007-04-01

    We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. With the more consistent vertex used here, the error in ladder-rainbow truncation for vector mesons is never more than 10% as the current quark mass is varied from the u/d region to the b region.

  3. Quark-gluon vertex dressing and meson masses beyond ladder-rainbow truncation

    SciTech Connect

    Matevosyan, Hrayr H.; Thomas, Anthony W.; Tandy, Peter C.

    2007-04-15

    We include a generalized infinite class of quark-gluon vertex dressing diagrams in a study of how dynamics beyond the ladder-rainbow truncation influences the Bethe-Salpeter description of light-quark pseudoscalar and vector mesons. The diagrammatic specification of the vertex is mapped into a corresponding specification of the Bethe-Salpeter kernel, which preserves chiral symmetry. This study adopts the algebraic format afforded by the simple interaction kernel used in previous work on this topic. The new feature of the present work is that in every diagram summed for the vertex and the corresponding Bethe-Salpeter kernel, each quark-gluon vertex is required to be the self-consistent vertex solution. We also adopt from previous work the effective accounting for the role of the explicitly non-Abelian three-gluon coupling in a global manner through one parameter determined from recent lattice-QCD data for the vertex. Within the current model, the more consistent dressed vertex limits the ladder-rainbow truncation error for vector mesons to be never more than 10% as the current quark mass is varied from the u/d region to the b region.

  4. Up- and down-quark masses from finite-energy QCD sum rules to five loops

    SciTech Connect

    Dominguez, C. A.; Nasrallah, N. F.; Roentsch, R. H.; Schilcher, K.

    2009-01-01

    The up- and down-quark masses are determined from an optimized QCD finite-energy sum rule involving the correlator of axial-vector divergences, to five-loop order in perturbative QCD, and including leading nonperturbative QCD and higher order quark-mass corrections. This finite-energy sum rule is designed to reduce considerably the systematic uncertainties arising from the (unmeasured) hadronic resonance sector, which in this framework contributes less than 3-4% to the quark mass. This is achieved by introducing an integration kernel in the form of a second degree polynomial, restricted to vanish at the peak of the two lowest lying resonances. The driving hadronic contribution is then the pion pole, with parameters well known from experiment. The determination is done in the framework of contour improved perturbation theory, which exhibits a very good convergence, leading to a remarkably stable result in the unusually wide window s{sub 0}=1.0-4.0 GeV{sup 2}, where s{sub 0} is the radius of the integration contour in the complex energy (squared) plane. The results are m{sub u}(Q=2 GeV)=2.9{+-}0.2 MeV, m{sub d}(Q=2 GeV)=5.3{+-}0.4 MeV, and (m{sub u}+m{sub d})/2=4.1{+-}0.2 MeV (at a scale Q=2 GeV)

  5. Transverse Quark Spin Effects and the Flavor Dependence of the Boer-Mulders Function

    SciTech Connect

    Leonard P. Gamberg; Gary R. Goldstein; Marc Schlegel

    2007-07-30

    The naive time reversal odd (T-odd) parton distribution $h_{1}^{\\perp}$, the so-called Boer-Mulders function, for both $u$- and $d$-quarks is considered in the diquark spectator model. While other approaches give evidence that the signs of the Boer-Mulders function for both flavors $u$ and $d$ are the same and negative, previous caculations in the diquark-spectator model found $h_{1}^{\\perp(u)}$ and $h_{1}^{\\perp(d)}$ have differnet signs. The flavor dependence is of significance for the analysis of the azimuthal $\\cos(2\\phi)$ asymmetries in unpolarized SIDIS and DY-processes, as well as for the overall physical understanding of the distribution of transversely polarized quarks in unpolarized nucleons. We find substantial differences with previous work. In particular we obtain estimates of the zeroth, half and first moments of Boer-Mulders functions that are negative over the full range in Bjorken $x$ for both the up and down quarks. In conjunction with the Collins function we then predict the $\\cos(2\\phi)$ azimuthal asymmetry for $\\pi^{+}$ and $\\pi^{-}$ in this framework. We also find that the Sivers up and down quark are negative and postive respectively. As a by-product of the formalism, we calculate the chiral-odd but T-even function $h_{1L}^{\\perp}$ in the spectator framework, which allows us to present a prediction for the single spin asymmetry $A_{UL}^{\\sin(2\\phi)}$ for a longitudinally polarized target in SIDIS.

  6. Measurement of the top quark mass in the lepton+jets final state with the matrix element method

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Agelou, M.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; /Buenos Aires U. /Rio de Janeiro, CBPF /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U. /Prague, Tech. U.

    2006-09-01

    We present a measurement of the top quark mass with the Matrix Element method in the lepton+jets final state. As the energy scale for calorimeter jets represents the dominant source of systematic uncertainty, the Matrix Element likelihood is extended by an additional parameter, which is defined as a global multiplicative factor applied to the standard energy scale. The top quark mass is obtained from a fit that yields the combined statistical and systematic jet energy scale uncertainty.

  7. Top quark physics experimental results at the LHC: Cross section and mass measurements with the CMS experiment

    NASA Astrophysics Data System (ADS)

    Gallinaro, M.

    2016-07-01

    The top quark, the heaviest known elementary particle discovered at the Fermilab Tevatron almost exactly twenty years ago, has taken a central role in the study of fundamental interactions. Its large mass suggests that it may play a special role in Nature. With approximately 25fb-1 of data collected by the CMS experiments at the Large Hadron Collider in Run 1 (2010-2012), top quark physics is at a turning point from first studies to precision measurements with sensitivity to new physics processes. This report summarizes the latest experimental results on top quark production cross section and mass measurements.

  8. Measurement of the mass difference between $t$ and $\\bar{t}$ quarks

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2011-03-01

    We present a direct measurement of the mass difference between t and {bar t} quarks using t{bar t} candidate events in the lepton+jets channel, collected with the CDF II detector at Fermilab's 1.96 TeV Tevatron p{bar p} Collider. We make an event by event estimate of the mass difference to construct templates for top quark pair signal events and background events. The resulting mass difference distribution of data is compared to templates of signals and background using a maximum likelihood fit. From a sample corresponding to an integrated luminosity of 5.6 fb{sup -1}, we measure a mass difference, {Delta}M{sub top} = M{sub t} - M{sub {bar t}} = -3.3 {+-} 1.4 (stat) {+-} 1.0 (syst) GeV/c{sup 2}, approximately two standard deviations away from the CPT hypothesis of zero mass difference. This is the most precise measurement of a mass difference between t and its {bar t} partner to date.

  9. Masses of third family vectorlike quarks and leptons in Yukawa-unified E6

    NASA Astrophysics Data System (ADS)

    Hebbar, Aditya; Leontaris, George K.; Shafi, Qaisar

    2016-06-01

    In supersymmetric E6 the masses of the third family quarks and charged lepton, t -b -τ , as well as the masses of the vectorlike quarks and leptons, D -D ¯ and L -L ¯, may arise from the coupling 2 73×2 73×2 7H, where 2 73 and 2 7H denote the third family matter and Higgs multiplets, respectively. We assume that the SO(10) singlet component in 2 7H acquires a TeV-scale vacuum expectation value that spontaneously breaks U (1 )ψ and provides masses to the vectorlike particles in 2 73, while the Minimal Supersymmetric Standard Model doublets in 2 7H provide masses to t , b , and τ . Imposing Yukawa coupling unification ht=hb=hτ=hD=hL at MGUT and employing the ATLAS and CMS constraints on the Zψ' boson mass, we estimate the lower bounds on the third family vectorlike particles D -D ¯ and L -L ¯ masses to be around 5.85 TeV and 2.9 TeV, respectively. These bounds apply in the supersymmetric limit.

  10. Measurement of the top quark mass in the dilepton final state using the matrix element method

    SciTech Connect

    Grohsjean, Alexander; /Munich U.

    2008-12-01

    The top quark, discovered in 1995 by the CDF and D0 experiments at the Fermilab Tevatron Collider, is the heaviest known fundamental particle. The precise knowledge of its mass yields important constraints on the mass of the yet-unobserved Higgs boson and allows to probe for physics beyond the Standard Model. The first measurement of the top quark mass in the dilepton channel with the Matrix Element method at the D0 experiment is presented. After a short description of the experimental environment and the reconstruction chain from hits in the detector to physical objects, a detailed review of the Matrix Element method is given. The Matrix Element method is based on the likelihood to observe a given event under the assumption of the quantity to be measured, e.g. the mass of the top quark. The method has undergone significant modifications and improvements compared to previous measurements in the lepton+jets channel: the two undetected neutrinos require a new reconstruction scheme for the four-momenta of the final state particles, the small event sample demands the modeling of additional jets in the signal likelihood, and a new likelihood is designed to account for the main source of background containing tauonic Z decay. The Matrix Element method is validated on Monte Carlo simulated events at the generator level. For the measurement, calibration curves are derived from events that are run through the full D0 detector simulation. The analysis makes use of the Run II data set recorded between April 2002 and May 2008 corresponding to an integrated luminosity of 2.8 fb{sup -1}. A total of 107 t{bar t} candidate events with one electron and one muon in the final state are selected. Applying the Matrix Element method to this data set, the top quark mass is measured to be m{sub top}{sup Run IIa} = 170.6 {+-} 6.1(stat.){sub -1.5}{sup +2.1}(syst.)GeV; m{sub top}{sup Run IIb} = 174.1 {+-} 4.4(stat.){sub -1.8}{sup +2.5}(syst.)GeV; m{sub top}{sup comb} = 172.9 {+-} 3.6(stat

  11. Radiative origin of all quark and lepton masses through dark matter with flavor symmetry.

    PubMed

    Ma, Ernest

    2014-03-01

    The fundamental issue of the origin of mass for all quarks and leptons (including Majorana neutrinos) is linked to dark matter, odd under an exactly conserved Z2 symmetry which may or may not be derivable from an U(1)D gauge symmetry. The observable sector interacts with a proposed dark sector which consists of heavy neutral singlet Dirac fermions and suitably chosen new scalars. Flavor symmetry is implemented in a renormalizable context with just the one Higgs doublet (ϕ(+), ϕ(0)) of the standard model in such a way that all observed fermions obtain their masses radiatively through dark matter. PMID:24655241

  12. Top quark mass: Latest CDF results, Tevatron combination and electroweak implications

    SciTech Connect

    Vellidis, Costas

    2009-10-01

    A summary of the most up-to-date top quark mass measurements at CDF is presented. These analyses use top-antitop candidate events detected in the CDF experiment at the Tevatron collider with an integrated luminosity of up to {approx}3/fb. The combination of all those measurements together with the corresponding top mass measurements from the concurrently running D0 experiment at the Tevatron yields a world average of M{sub t} = [173.1 {+-} 0.6(stat.) {+-} 1.1(syst.)] GeV/c{sup 2}.

  13. Direct measurement of the top quark mass by the DØ Collaboration

    NASA Astrophysics Data System (ADS)

    Abbott, B.; Abolins, M.; Acharya, B. S.; Adam, I.; Adams, D. L.; Adams, M.; Ahn, S.; Aihara, H.; Alves, G. A.; Amos, N.; Anderson, E. W.; Astur, R.; Baarmand, M. M.; Baden, A.; Balamurali, V.; Balderston, J.; Baldin, B.; Banerjee, S.; Bantly, J.; Barberis, E.; Bartlett, J. F.; Bazizi, K.; Belyaev, A.; Beri, S. B.; Bertram, I.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Biswas, N.; Blazey, G.; Blessing, S.; Bloom, P.; Boehnlein, A.; Bojko, N. I.; Borcherding, F.; Boswell, C.; Brandt, A.; Brock, R.; Bross, A.; Buchholz, D.; Burtovoi, V. S.; Butler, J. M.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chang, S.-M.; Chekulaev, S. V.; Chen, L.-P.; Chen, W.; Choi, S.; Chopra, S.; Choudhary, B. C.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Cobau, W. G.; Cochran, J.; Coney, L.; Cooper, W. E.; Cretsinger, C.; Cullen-Vidal, D.; Cummings, M. A.; Cutts, D.; Dahl, O. I.; Davis, K.; de, K.; del Signore, K.; Demarteau, M.; Denisov, D.; Denisov, S. P.; Diehl, H. T.; Diesburg, M.; di Loreto, G.; Draper, P.; Ducros, Y.; Dudko, L. V.; Dugad, S. R.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Evdokimov, V. N.; Fahland, T.; Fatyga, M. K.; Feher, S.; Fein, D.; Ferbel, T.; Finocchiaro, G.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Forden, G. E.; Fortner, M.; Frame, K. C.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gartung, P.; Geld, T. L.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gibbard, B.; Glenn, S.; Gobbi, B.; Goldschmidt, A.; Gómez, B.; Gómez, G.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, D. R.; Greenlee, H.; Grim, G.; Grinstein, S.; Grossman, N.; Grudberg, P.; Grünendahl, S.; Guglielmo, G.; Guida, J. A.; Guida, J. M.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, P.; Gutnikov, Y. E.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hahn, K. S.; Hall, R. E.; Hanlet, P.; Hansen, S.; Hauptman, J. M.; Hedin, D.; Heinson, A. P.; Heintz, U.; Hernández-Montoya, R.; Heuring, T.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Hoftun, J. S.; Hsieh, F.; Hu, Ting; Hu, Tong; Huehn, T.; Ito, A. S.; James, E.; Jaques, J.; Jerger, S. A.; Jesik, R.; Jiang, J. Z.-Y.; Joffe-Minor, T.; Johns, K.; Johnson, M.; Jonckheere, A.; Jones, M.; Jöstlein, H.; Jun, S. Y.; Jung, C. K.; Kahn, S.; Kalbfleisch, G.; Kang, J. S.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Kelly, M. L.; Kim, C. L.; Kim, S. K.; Klatchko, A.; Klima, B.; Klopfenstein, C.; Klyukhin, V. I.; Kochetkov, V. I.; Kohli, J. M.; Koltick, D.; Kostritskiy, A. V.; Kotcher, J.; Kotwal, A. V.; Kourlas, J.; Kozelov, A. V.; Kozlovski, E. A.; Krane, J.; Krishnaswamy, M. R.; Krzywdzinski, S.; Kunori, S.; Lami, S.; Lander, R.; Landry, F.; Landsberg, G.; Lauer, B.; Leflat, A.; Li, H.; Li, J.; Li-Demarteau, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Liu, Y. C.; Lobkowicz, F.; Loken, S. C.; Lökös, S.; Lueking, L.; Lyon, A. L.; Maciel, A. K.; Madaras, R. J.; Madden, R.; Magaña-Mendoza, L.; Manankov, V.; Mani, S.; Mao, H. S.; Markeloff, R.; Marshall, T.; Martin, M. I.; Mauritz, K. M.; May, B.; Mayorov, A. A.; McCarthy, R.; McDonald, J.; McKibben, T.; McKinley, J.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miettinen, H.; Mincer, A.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Mooney, P.; da Motta, H.; Murphy, C.; Nang, F.; Narain, M.; Narasimham, V. S.; Narayanan, A.; Neal, H. A.; Negret, J. P.; Nemethy, P.; Norman, D.; Oesch, L.; Oguri, V.; Oliveira, E.; Oltman, E.; Oshima, N.; Owen, D.; Padley, P.; Para, A.; Park, Y. M.; Partridge, R.; Parua, N.; Paterno, M.; Pawlik, B.; Perkins, J.; Peters, M.; Piegaia, R.; Piekarz, H.; Pischalnikov, Y.; Podstavkov, V. M.; Pope, B. G.; Prosper, H. B.; Protopopescu, S.; Qian, J.; Quintas, P. Z.; Raja, R.; Rajagopalan, S.; Ramirez, O.; Rasmussen, L.; Reucroft, S.; Rijssenbeek, M.; Rockwell, T.; Roco, M.; Roe, N. A.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sánchez-Hernández, A.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Sculli, J.; Shabalina, E.; Shaffer, C.; Shankar, H. C.; Shivpuri, R. K.; Shupe, M.; Singh, H.; Singh, J. B.; Sirotenko, V.; Smart, W.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Sood, P. M.; Sosebee, M.; Sotnikova, N.; Souza, M.; Spadafora, A. L.; Steinbrück, G.; Stephens, R. W.; Stevenson, M. L.; Stewart, D.; Stichelbaut, F.; Stoianova, D. A.; Stoker, D.; Strauss, M.; Streets, K.; Strovink, M.; Sznajder, A.; Tamburello, P.; Tarazi, J.; Tartaglia, M.; Thomas, T. L.; Thompson, J.; Trippe, T. G.; Tuts, P. M.; Varelas, N.; Varnes, E. W.; Vititoe, D.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, G.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Wightman, J. A.; Willis, S.; Wimpenny, S. J.; Wirjawan, J. V.; Womersley, J.; Won, E.; Wood, D. R.; Xu, H.; Yamada, R.; Yamin, P.; Yang, J.; Yasuda, T.; Yepes, P.; Yoshikawa, C.; Youssef, S.; Yu, J.; Yu, Y.; Zhu, Z. H.; Zieminska, D.; Zieminski, A.; Zverev, E. G.; Zylberstejn, A.

    1998-09-01

    We determine the top quark mass mt using tt¯ pairs produced in the DØ detector by s=1.8 TeV pp¯ collisions in a 125 pb-1 exposure at the Fermilab Tevatron. We make a two constraint fit to mt in tt¯-->bW+b¯W- final states with one W boson decaying to qq¯ and the other to eν or μν. Likelihood fits to the data yield mt(l+jets)=173.3+/-5.6 (stat) +/- 5.5 (syst) GeV/c2. When this result is combined with an analysis of events in which both W bosons decay into leptons, we obtain mt=172.1+/-5.2 (stat) +/- 4.9 (syst) GeV/c2. An alternate analysis, using three constraint fits to fixed top quark masses, gives mt(l+jets)=176.0+/-7.9 (stat)+/- 4.8 (syst) GeV/c2, consistent with the above result. Studies of kinematic distributions of the top quark candidates are also presented. 14.65.Ha, 13.85.Ni, 13.85.Qk

  14. Determination of hadron-quark phase transition line from lattice QCD and two-solar-mass neutron star observations

    NASA Astrophysics Data System (ADS)

    Sugano, Junpei; Kouno, Hiroaki; Yahiro, Masanobu

    2016-07-01

    We aim at drawing the hadron-quark phase transition line in the QCD phase diagram by using the two-phase model (TPM) in which the entanglement Polyakov-loop extended Nambu-Jona-Lasinio (EPNJL) model with the vector-type four-quark interaction is used for the quark phase and the relativistic mean field (RMF) model is used for the hadron phase. A reasonable TPM is constructed by using lattice QCD data and neutron star observations as reliable constraints. For the EPNJL model, we determine the strength of vector-type four-quark interaction at zero quark chemical potential from lattice QCD data on quark number density normalized by its Stefan-Boltzmann limit. For the hadron phase, we consider three RMF models: NL3; TM1; and the model proposed by Maruyama, Tatsumi, Endo, and Chiba (MTEC). We find that MTEC is most consistent with the neutron star observations and TM1 is the second best. Assuming that the hadron-quark phase transition occurs in the core of a neutron star, we explore the density dependence of vector-type four-quark interaction. Particularly for the critical baryon chemical potential μBc at zero temperature, we determine a range of μBc for the quark phase to occur in the core of a neutron star. The values of μBc lie in the range 1560 MeV ≤μBc≤1910 MeV .

  15. Measurement of the top quark mass at CDF using the `neutrino phi weighting' template method on a lepton plus isolated track sample

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-01-01

    We present a measurement of the top quark mass with t{bar t} dilepton events produced in p{bar p} collisions at the Fermilab Tevatron ({radical}s = 1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb{sup -1}, are selected as t{bar t} candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles ({phi}{sub {nu}1}, {phi}{sub {nu}2}) of neutrinos and reconstruct the top quark mass for each {phi}{sub {nu}1}, {phi}{sub {nu}2} pair by minimizing a {chi}{sup 2} function in the t{bar t} dilepton hypothesis. We assign {chi}{sup 2}-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t{bar t} and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5{sub -3.3}{sup +3.4}(stat.){+-}3.1(syst.) GeV/c{sup 2}.

  16. Measurement of the top quark mass at CDF using the ``neutrino ϕ weighting'' template method on a lepton plus isolated track sample

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Adelman, J.; Akimoto, T.; González, B. Álvarez; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; Arisawa, T.; Artikov, A.; Ashmanskas, W.; Attal, A.; Aurisano, A.; Azfar, F.; Azzurri, P.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Bartsch, V.; Bauer, G.; Beauchemin, P.-H.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Beringer, J.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Blair, R. E.; Blocker, C.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Boisvert, V.; Bolla, G.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Bridgeman, A.; Brigliadori, L.; Bromberg, C.; Brubaker, E.; Budagov, J.; Budd, H. S.; Budd, S.; Burke, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Byrum, K. L.; Cabrera, S.; Calancha, C.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chang, S. H.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Choudalakis, G.; Chuang, S. H.; Chung, K.; Chung, W. H.; Chung, Y. S.; Chwalek, T.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Clark, D.; Compostella, G.; Convery, M. E.; Conway, J.; Cordelli, M.; Cortiana, G.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Almenar, C. Cuenca; Cuevas, J.; Culbertson, R.; Cully, J. C.; Dagenhart, D.; Datta, M.; Davies, T.; de Barbaro, P.; de Cecco, S.; Deisher, A.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Derwent, P. F.; di Giovanni, G. P.; Dionisi, C.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Donini, J.; Dorigo, T.; Dube, S.; Efron, J.; Elagin, A.; Erbacher, R.; Errede, D.; Errede, S.; Eusebi, R.; Fang, H. C.; Farrington, S.; Fedorko, W. T.; Feild, R. G.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garberson, F.; Garcia, J. E.; Garfinkel, A. F.; Genser, K.; Gerberich, H.; Gerdes, D.; Gessler, A.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Gimmell, J. L.; Ginsburg, C. M.; Giokaris, N.; Giordani, M.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Grundler, U.; da Costa, J. Guimaraes; Gunay-Unalan, Z.; Haber, C.; Hahn, K.; Hahn, S. R.; Halkiadakis, E.; Han, B.-Y.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harper, S.; Harr, R. F.; Harris, R. M.; Hartz, M.; Hatakeyama, K.; Hays, C.; Heck, M.; Heijboer, A.; Heinrich, J.; Henderson, C.; Herndon, M.; Heuser, J.; Hewamanage, S.; Hidas, D.; Hill, C. S.; Hirschbuehl, D.; Hocker, A.; Hou, S.; Houlden, M.; Hsu, S.-C.; Huffman, B. T.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Incandela, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Jung, J. E.; Junk, T. R.; Kamon, T.; Kar, D.; Karchin, P. E.; Kato, Y.; Kephart, R.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirsch, L.; Klimenko, S.; Knuteson, B.; Ko, B. R.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Korytov, A.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kubo, T.; Kuhr, T.; Kulkarni, N. P.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, S. W.; Leone, S.; Lewis, J. D.; Lin, C.-S.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, T.; Lockyer, N. S.; Loginov, A.; Loreti, M.; Lovas, L.; Lucchesi, D.; Luci, C.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lyons, L.; Lys, J.; Lysak, R.; MacQueen, D.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maki, T.; Maksimovic, P.; Malde, S.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Marino, C. P.; Martin, A.; Martin, V.; Martínez, M.; Martínez-Ballarín, R.; Maruyama, T.; Mastrandrea, P.; Masubuchi, T.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Merkel, P.; Mesropian, C.; Miao, T.; Miladinovic, N.; Miller, R.; Mills, C.; Milnik, M.; Mitra, A.; Mitselmakher, G.; Miyake, H.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Fernandez, P. Movilla; Mülmenstädt, J.; Mukherjee, A.; Muller, Th.; Mumford, R.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Nagano, A.; Naganoma, J.; Nakamura, K.; Nakano, I.; Napier, A.; Necula, V.; Nett, J.; Neu, C.; Neubauer, M. S.; Neubauer, S.; Nielsen, J.; Nodulman, L.; Norman, M.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Osterberg, K.; Griso, S. Pagan; Palencia, E.; Papadimitriou, V.; Papaikonomou, A.; Paramonov, A. A.; Parks, B.; Pashapour, S.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Peiffer, T.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pinera, L.; Pitts, K.; Plager, C.; Pondrom, L.; Poukhov, O.; Pounder, N.; Prakoshyn, F.; Pronko, A.; Proudfoot, J.; Ptohos, F.; Pueschel, E.; Punzi, G.; Pursley, J.; Rademacker, J.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Renz, M.; Rescigno, M.; Richter, S.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Rossi, M.; Rossin, R.; Roy, P.; Ruiz, A.; Russ, J.; Rusu, V.; Rutherford, B.; Saarikko, H.; Safonov, A.; Sakumoto, W. K.; Saltó, O.; Santi, L.; Sarkar, S.; Sartori, L.; Sato, K.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, A.; Schmidt, E. E.; Schmidt, M. A.; Schmidt, M. P.; Schmitt, M.; Schwarz, T.; Scodellaro, L.; Scribano, A.; Scuri, F.; Sedov, A.; Seidel, S.; Seiya, Y.; Semenov, A.; Sexton-Kennedy, L.; Sforza, F.; Sfyrla, A.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shiraishi, S.; Shochet, M.; Shon, Y.; Shreyber, I.; Sidoti, A.; Sinervo, P.; Sisakyan, A.; Slaughter, A. J.; Slaunwhite, J.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Snihur, R.; Soha, A.; Somalwar, S.; Sorin, V.; Spalding, J.; Spreitzer, T.; Squillacioti, P.; Stanitzki, M.; St. Denis, R.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Strycker, G. L.; Stuart, D.; Suh, J. S.; Sukhanov, A.; Suslov, I.; Suzuki, T.; Taffard, A.; Takashima, R.; Takeuchi, Y.; Tanaka, R.; Tecchio, M.; Teng, P. K.; Terashi, K.; Thom, J.; Thompson, A. S.; Thompson, G. A.; Thomson, E.; Tipton, P.; Ttito-Guzmán, P.; Tkaczyk, S.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Tourneur, S.; Trovato, M.; Tsai, S.-Y.; Tu, Y.; Turini, N.; Ukegawa, F.; Vallecorsa, S.; van Remortel, N.; Varganov, A.; Vataga, E.; Vázquez, F.; Velev, G.; Vellidis, C.; Vidal, M.; Vidal, R.; Vila, I.; Vilar, R.; Vine, T.; Vogel, M.; Volobouev, I.; Volpi, G.; Wagner, P.; Wagner, R. G.; Wagner, R. L.; Wagner, W.; Wagner-Kuhr, J.; Wakisaka, T.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Weinberger, M.; Weinelt, J.; Wester, W. C., III; Whitehouse, B.; Whiteson, D.; Wicklund, A. B.; Wicklund, E.; Wilbur, S.; Williams, G.; Williams, H. H.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, C.; Wright, T.; Wu, X.; Würthwein, F.; Xie, S.; Yagil, A.; Yamamoto, K.; Yamaoka, J.; Yang, U. K.; Yang, Y. C.; Yao, W. M.; Yeh, G. P.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Yu, S. S.; Yun, J. C.; Zanello, L.; Zanetti, A.; Zhang, X.; Zheng, Y.; Zucchelli, S.

    2009-04-01

    We present a measurement of the top quark mass with t tmacr dilepton events produced in p pmacr collisions at the Fermilab Tevatron (s=1.96TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9fb-1, are selected as t tmacr candidates. To account for the unconstrained event kinematics, we scan over the phase space of the azimuthal angles (ϕν1,ϕν2) of neutrinos and reconstruct the top quark mass for each ϕν1, ϕν2 pair by minimizing a χ2 function in the t tmacr dilepton hypothesis. We assign χ2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t tmacr and background events, and parametrized in order to provide continuous probability density functions. A likelihood fit to the mass distribution in data as a weighted sum of signal and background probability density functions gives a top quark mass of 165.5-3.3+3.4(stat)±3.1(syst)GeV/c2.

  17. Physical Origin of Density Dependent Force of the Skyrme Type within the Quark Meson Coupling Model

    SciTech Connect

    Pierre Guichon; Hrayr Matevosyan; N. Sandulescu; Anthony Thomas

    2006-03-17

    A density dependent, effective nucleon-nucleon force of the Skyrme type is derived from the quark-meson coupling model--a self-consistent, relativistic quark level description of nuclear matter. This new formulation requires no assumption that the mean scalar field is small and hence constitutes a significant advance over earlier work. The similarity of the effective interaction to the widely used SkM* force encourages us to apply it to a wide range of nuclear problems, beginning with the binding energies and charge distributions of doubly magic nuclei. Finding impressive results in this conventional arena, we apply the same effective interaction, within the Hartree-Fock-Bogoliubov approach, to the properties of nuclei far from stability. The resulting two neutron drip lines and shell quenching are quite satisfactory. Finally, we apply the relativistic formulation to the properties of dense nuclear matter in anticipation of future application to the properties of neutron stars.

  18. Measurement of the Top Quark Mass Using the Invariant Mass of Lepton Pairs in Soft Muon b-tagged Events

    SciTech Connect

    Aaltonen, T.; Adelman, Jahred A.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2009-06-01

    We present the first measurement of the mass of the top quark in a sample of t{bar t} {yields} {ell}{bar {nu}}b{bar b}q{bar q} events (where {ell} = e, {mu}) selected by identifying jets containing a muon candidate from the semileptonic decay of heavy-flavor hadrons (soft muon b-tagging). The p{bar p} collision data used corresponds to an integrated luminosity of 2 fb{sup -1} and was collected by the CDF II detector at the Fermilab Tevatron. The measurement is based on a novel technique exploiting the invariant mass of a subset of the decay particles, specifically the lepton from the W boson of the t {yields} Wb decay, and the muon from a semileptonic b decay. We fit template histograms, derived from simulation of t{bar t} events and a modeling of the background, to the mass distribution observed in the data and measure a top quark mass of 180.5 {+-} 12.0(stat.) {+-} 3.6(syst.) GeV/c{sup 2}, consistent with the current world average.

  19. Hadron spectrum, quark masses, and decay constants from light overlap fermions on large lattices

    SciTech Connect

    Galletly, D.; Horsley, R.; Guertler, M.; Perlt, H.; Schiller, A.; Rakow, P. E. L.; Schierholz, G.; Streuer, T.

    2007-04-01

    We present results from a simulation of quenched overlap fermions with Luescher-Weisz gauge field action on lattices up to 24{sup 3}48 and for pion masses down to {approx_equal}250 MeV. Among the quantities we study are the pion, rho, and nucleon masses; the light and strange quark masses; and the pion decay constant. The renormalization of the scalar and axial vector currents is done nonperturbatively in the RI-MOM scheme. The simulations are performed at two different lattice spacings, a{approx_equal}0.1 fm and {approx_equal}0.15 fm, and on two different physical volumes, to test the scaling properties of our action and to study finite volume effects. We compare our results with the predictions of chiral perturbation theory and compute several of its low-energy constants. The pion mass is computed in sectors of fixed topology as well.

  20. Scalar K{pi} form factor and light-quark masses

    SciTech Connect

    Jamin, Matthias; Oller, Jose Antonio; Pich, Antonio

    2006-10-01

    Recent experimental improvements on K-decay data allow for a precise extraction of the strangeness-changing scalar K{pi} form factor and the related strange scalar spectral function. On the basis of this scalar as well as the corresponding pseudoscalar spectral function, the strange quark mass is determined to be m{sub s}(2 GeV)=92{+-}9 MeV. Further taking into account chiral perturbation theory mass ratios, the light up and down quark masses turn out to be m{sub u}(2 GeV)=2.7{+-}0.4 MeV as well as m{sub d}(2 GeV)=4.8{+-}0.5 MeV. As a by-product, we also find a value for the Cabibbo angle |V{sub us}|=0.2236(29) and the ratio of meson decay constants F{sub K}/F{sub {pi}}=1.203(16). Performing a global average of the strange mass by including extractions from other channels as well as lattice QCD results yields m{sub s}(2 GeV)=94{+-}6 MeV.

  1. A Measurement of the Mass of the Top Quark in Lepton + Jets Events at CDF

    SciTech Connect

    Brubaker, Erik Matthews

    2004-12-01

    This document presents a measurement of the top quark mass using the CDF run II detector at Fermilab. Colliding beams of protons and anti-protons at Fermilab's Tevatron ({radical}s = 1.96 TeV) produce top/anti-top pairs, which decay to W{sup +}W{sup -} b{bar b}; events are selected where one W decays hadronically, and one W decays to either e or {mu} plus a neutrino. The data sample was collected between March 2002 and September 2003, and corresponds to an integrated luminosity of approximately 162 pb{sup -1}. Thirty-seven candidate t{bar t} events are found with at least one b jet identified by its displaced vertex. In each event, the best fit top quark invariant mass is determined by minimizing a {chi}{sup 2} for the overconstrained kinematic system. A likelihood fit of the reconstructed masses in the data sample to distributions from simulated signal and background events gives a top mass of 174.9{sub -7.7}{sup +7.1}(stat.) {+-} 6.5(syst.) GeV/c{sup 2}. The dominant systematic error is due to uncertainties in the jet energy measurements.

  2. Temperature dependence of quarks and gluon vacuum condensate in the Dyson-Schwinger Equations at finite temperature

    NASA Astrophysics Data System (ADS)

    Zhou, Li-Juan; Zheng, Bo; Zhong, Hong-Wei; Ma, Wei-Xing

    2015-03-01

    Based on the Dyson-Schwinger Equations (DSEs), the two-quark vacuum condensate, the four-quark vacuum condensate, and the quark gluon mixed vacuum condensate in the non-perturbative QCD vacuum state are investigated by solving the DSEs with rainbow truncation at zero- and finite- temperature, respectively. These condensates are important input parameters in QCD sum rule with zero and finite temperature, and in studying hadron physics, as well as predicting the quark mean squared momentum m20- also called quark virtuality in the QCD vacuum state. The present calculated results show that these physical quantities are almost independent of the temperature below the critical point temperature Tc = 131 MeV, and above Tc the chiral symmetry is restored. For comparison we calculate the temperature dependence of the “in-hadron condensate” for pion. At the same time, we also calculate the ratio of the quark gluon mixed vacuum condensate to the two-quark vacuum condensate by using these condensates, and the unknown quark mean squared momentum in the QCD vacuum state has been obtained. The results show that the ratio m20(T) is almost flat in the temperature region from 0 to Tc, although there are drastic changes of the quark vacuum condensate and the quark gluon mixed vacuum condensate at the region. Our predicted ratio comes out to be m20(T)=2.41 GeV2 at the Chiral limit, which is consistent with other theory model predictions, and strongly indicates the significance that the quark gluon mixed vacuum condensate has played in the virtuality calculations. Supported by National Natural Science Foundation of China (11365002), Guangxi Natural Science Foundation for Young Researchers (2013GXNSFBB053007, 2011GXNSFA018140), Guangxi Education Department (2013ZD049), Guangxi Grant for Excellent Researchers (2011-54), and Guangxi University of Science and Technology Foundation for PhDs (11Z16)

  3. Quark-lepton mass relation and CKM mixing in an A4 extension of the minimal supersymmetric standard model

    NASA Astrophysics Data System (ADS)

    Morisi, S.; Nebot, M.; Patel, Ketan M.; Peinado, E.; Valle, J. W. F.

    2013-08-01

    An interesting mass relation between down-type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)c⊗SU(2)L⊗U(1)Y model based on the A4 flavor symmetry. Here we propose a simple extension which provides an adequate full description of the quark sector. By adding a pair of vectorlike up quarks, we show how the CKM entries Vub, Vcb, Vtd and Vts arise from deviations of the unitarity. We perform an analysis including the most relevant observables in the quark sector, such as oscillations and rare decays of kaons, Bd and Bs mesons. In the lepton sector, the model predicts an inverted hierarchy for the neutrino masses, leading to a potentially observable rate of neutrinoless double beta decay.

  4. Direct determinations of the nucleon and pion σ terms at nearly physical quark masses

    NASA Astrophysics Data System (ADS)

    Bali, Gunnar S.; Collins, Sara; Richtmann, Daniel; Schäfer, Andreas; Söldner, Wolfgang; Sternbeck, André; RQCD Collaboration

    2016-05-01

    We present a high statistics study of the pion and nucleon light and strange quark sigma terms using Nf=2 dynamical nonperturbatively improved clover fermions with a range of pion masses down to mπ˜150 MeV and several volumes, L mπ=3.4 up to 6.7, and lattice spacings, a =0.06 - 0.08 fm , enabling a study of finite volume and discretization effects for mπ≳260 MeV . Systematics are found to be reasonably under control. For the nucleon we obtain σπ N=35 (6 ) MeV and σs=35 (12 ) MeV , or equivalently in terms of the quark fractions, fTu=0.021 (4 ) , fTd=0.016 (4 ) and fTs=0.037 (13 ) , where the errors include estimates of both the systematic and statistical uncertainties. These values, together with perturbative matching in the heavy quark limit, lead to fTc=0.075(4 ), fT b=0.072 (2 ) and fT t=0.070 (1 ). In addition, through the use of the (inverse) Feynman-Hellmann theorem our results for σπ N are shown to be consistent with the nucleon masses determined in the analysis. For the pion we implement a method which greatly reduces excited state contamination to the scalar matrix elements from states traveling across the temporal boundary. This enables us to demonstrate the Gell-Mann-Oakes-Renner expectation σπ=mπ/2 over our range of pion masses.

  5. Testing realistic quark mass matrices in the custodial Randall-Sundrum model with flavor changing top decays

    NASA Astrophysics Data System (ADS)

    Chang, We-Fu; Ng, John N.; Wu, Jackson M. S.

    2008-11-01

    We study quark mass matrices in the Randall-Sundrum (RS) model with bulk symmetry SU(2)L×SU(2)R×U(1)B-L. The Yukawa couplings are assumed to be within an order of magnitude of each other, and perturbative. We find that quark mass matrices of the symmetrical form proposed by Koide et al. [Y. Koide, H. Nishiura, K. Matsuda, T. Kikuchi, and T. Fukuyama, Phys. Rev. D 66, 093006 (2002)PRVDAQ0556-282110.1103/PhysRevD.66.093006] can be accommodated in the RS framework with the assumption of hierarchyless Yukawa couplings, but not the Hermitian Fritzsch-type mass matrices. General asymmetrical mass matrices are also found which fit well simultaneously with the quark masses and the Cabibbo-Kobayashi-Maskawa matrix. Both left-handed (LH) and right-handed (RH) quark rotation matrices are obtained that allow analysis of flavor changing decay of both LH and RH top quarks. At a warped down scale of 1.65 TeV, the total branching ratio of t→Z+jets can be as high as ˜5×10-6 for symmetrical mass matrices and ˜2×10-5 for asymmetrical ones. This level of signal is within reach of the LHC.

  6. Top-quark mass measurement in events with jets and missing transverse energy using the full CDF data set

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Ciocci, M. A.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; De Barbaro, P.; Demortier, L.; Deninno, M.; d'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Eusebi, R.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucà, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, P.; Martínez, M.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Ranjan, N.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sinervo, P.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; Stancari, M.; Denis, R. St.; Stelzer, B.; Stelzer-Chilton, O.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Warburton, A.; Waters, D.; Wester, W. C., III; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

    2013-07-01

    We present a measurement of the top-quark mass using the full data set of Tevatron s=1.96TeV proton-antiproton collisions recorded by the CDF II detector, corresponding to an integrated luminosity of 8.7fb-1. The analysis uses events with one semileptonic t or t¯ decay, but without detection of the electron or muon. We select events with significant missing transverse energy and multiple jets. We veto events containing identified electrons or muons. We obtain distributions of the top-quark masses and the invariant mass of the two jets from W-boson decays from data and compare these to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with in situ calibration. A likelihood fit of the templates from signal and background events to the data yields the top-quark mass, Mtop=173.93±1.64(stat)±0.87(syst)GeV/c2. This result is the most precise measurement to date of the mass of the top quark in this event topology.

  7. Two-loop perturbative quark mass renormalization from large {beta} Monte Carlo

    SciTech Connect

    Keisuke Jimmy Juge

    2001-02-14

    We present the calculation of heavy Wilson quark mass renormalization constants from large beta Monte Carlo simulations. Simulations were performed at various beta larger than 9, each on several spatial lattice sizes to allow for an infinite volume extrapolation. We use twisted boundary conditions to suppress tunneling and work in Coulomb gauge with appropriate adjustments for the temporal links. The one-loop coefficient obtained from this method is in agreement with the analytical result and a preliminary result for the second order coefficient is reported.

  8. Top quark mass measurement from dilepton events at CDF II with the matrix-element method

    SciTech Connect

    Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-05-01

    We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from p{bar p} collisions with {radical}s = 1.96 TeV at the Fermilab Tevatron. The likelihood in top mass is calculated for each event by convoluting the leading order matrix element describing q{bar q} {yields} t{bar t} {yields} b{ell}{nu}{sub {ell}}{bar b}{ell}{prime} {nu}{sub {ell}}, with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb{sup -1}, we observe 33 candidate events and measure M{sub top} = 165.2 {+-} 6.1(stat.) {+-} 3.4(syst.) GeV/c{sup 2}. This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.

  9. Ginzburg-Landau phase diagram for dense matter with axial anomaly, strange quark mass, and meson condensation

    SciTech Connect

    Schmitt, Andreas; Stetina, Stephan; Tachibana, Motoi

    2011-02-15

    We discuss the phase structure of dense matter, in particular, the nature of the transition between hadronic and quark matter. Calculations within a Ginzburg-Landau approach show that the axial anomaly can induce a critical point in this transition region. This is possible because in three-flavor quark matter with instanton effects a chiral condensate can be added to the color-flavor locked phase without changing the symmetries of the ground state. In (massless) two-flavor quark matter such a critical point is not possible since the corresponding color superconductor (2SC) does not break chiral symmetry. We study the effects of a nonzero but finite strange quark mass which interpolates between these two cases. Since at ultrahigh density the first reaction of the color-flavor locked phase to a nonzero strange quark mass is to develop a kaon condensate, we extend previous Ginzburg-Landau studies by including such a condensate. We discuss the fate of the critical point systematically and show that the continuity between hadronic and quark matter can be disrupted by the onset of a kaon condensate. Moreover, we identify the mass terms in the Ginzburg-Landau potential which are needed for the 2SC phase to occur in the phase diagram.

  10. Reformulations of the Yang-Mills theory toward quark confinement and mass gap

    NASA Astrophysics Data System (ADS)

    Kondo, Kei-Ichi; Kato, Seikou; Shibata, Akihiro; Shinohara, Toru

    2016-01-01

    We propose the reformulations of the SU (N) Yang-Mills theory toward quark confinement and mass gap. In fact, we have given a new framework for reformulating the SU (N) Yang-Mills theory using new field variables. This includes the preceding works given by Cho, Faddeev and Niemi, as a special case called the maximal option in our reformulations. The advantage of our reformulations is that the original non-Abelian gauge field variables can be changed into the new field variables such that one of them called the restricted field gives the dominant contribution to quark confinement in the gauge-independent way. Our reformulations can be combined with the SU (N) extension of the Diakonov-Petrov version of the non-Abelian Stokes theorem for the Wilson loop operator to give a gauge-invariant definition for the magnetic monopole in the SU (N) Yang-Mills theory without the scalar field. In the so-called minimal option, especially, the restricted field is non-Abelian and involves the non-Abelian magnetic monopole with the stability group U (N- 1). This suggests the non-Abelian dual superconductivity picture for quark confinement. This should be compared with the maximal option: the restricted field is Abelian and involves only the Abelian magnetic monopoles with the stability group U(1)N-1, just like the Abelian projection. We give some applications of this reformulation, e.g., the stability for the homogeneous chromomagnetic condensation of the Savvidy type, the large N treatment for deriving the dimensional transmutation and understanding the mass gap, and also the numerical simulations on a lattice which are given by Dr. Shibata in a subsequent talk.

  11. Transverse-momentum-dependent fragmentation and quark distribution functions from the Nambu-Jona-Lasinio-jet model

    NASA Astrophysics Data System (ADS)

    Matevosyan, Hrayr H.; Bentz, Wolfgang; Cloët, Ian C.; Thomas, Anthony W.

    2012-01-01

    Using the model of Nambu and Jona-Lasinio to provide a microscopic description of both the structure of the nucleon and of the quark to hadron elementary fragmentation functions, we investigate the transverse-momentum dependence of the unpolarized quark distributions in the nucleon and of the quark to pion and kaon fragmentation functions. The transverse-momentum dependence of the fragmentation functions is determined within a Monte Carlo framework, with the notable result that the average P⊥2 of the produced kaons is significantly larger than that of the pions. We also find that ⟨P⊥2⟩ has a sizable z dependence, in contrast with the naive Gaussian ansatz for the fragmentation functions. Diquark correlations in the nucleon give rise to a nontrivial flavor dependence in the unpolarized transverse-momentum-dependent quark distribution functions. The ⟨kT2⟩ of the quarks in the nucleon are also found to have a sizable x dependence. Finally, these results are used as input to a Monte Carlo event generator for semi-inclusive deep inelastic scattering (SIDIS), which is used to determine the average transverse momentum squared of the produced hadrons measured in SIDIS, namely, ⟨PT2⟩. Again, we find that the average PT2 of the produced kaons in SIDIS is significantly larger than that of the pions and in each case ⟨PT2⟩ has a sizable z dependence.

  12. Measurement of the top quark pair production cross section in proton-antiproton collisions at a center of mass energy of 1.96 TeV, hadronic top decays with the D0 detector

    SciTech Connect

    Hegeman, Jeroen Guido

    2009-01-16

    Of the six quarks in the standard model the top quark is by far the heaviest: 35 times more massive than its partner the bottom quark and more than 130 times heavier than the average of the other five quarks. Its correspondingly small decay width means it tends to decay before forming a bound state. Of all quarks, therefore, the top is the least affected by quark confinement, behaving almost as a free quark. Its large mass also makes the top quark a key player in the realm of the postulated Higgs boson, whose coupling strengths to particles are proportional to their masses. Precision measurements of particle masses for e.g. the top quark and the W boson can hereby provide indirect constraints on the Higgs boson mass. Since in the standard model top quarks couple almost exclusively to bottom quarks (t → Wb), top quark decays provide a window on the standard model through the direct measurement of the Cabibbo-Kobayashi-Maskawa quark mixing matrix element Vtb. In the same way any lack of top quark decays into W bosons could imply the existence of decay channels beyond the standard model, for example charged Higgs bosons as expected in two-doublet Higgs models: t → H+b. Within the standard model top quark decays can be classified by the (lepton or quark) W boson decay products. Depending on the decay of each of the W bosons, t$\\bar{t}$ pair decays can involve either no leptons at all, or one or two isolated leptons from direct W → e$\\bar{v}${sub e} and W → μ$\\bar{v}$μ decays. Cascade decays like b → Wc → e$\\bar{v}$ec can lead to additional non-isolated leptons. The fully hadronic decay channel, in which both Ws decay into a quark-antiquark pair, has the largest branching fraction of all t$\\bar{t}$ decay channels and is the only kinematically complete (i.e. neutrino-less) channel. It lacks, however, the clear isolated lepton signature and is therefore hard to distinguish from the multi-jet QCD background. It

  13. Measurement of the Hadronic Mass Spectrum in B to Xulnu Decaysand Determination of the b-Quark Mass at the BaBar Experiment

    SciTech Connect

    Tackmann, Kerstin

    2008-06-26

    similar accuracy. Through the comparison of this result to those obtained in other channels, this provides a test of the Heavy Quark Effective Theory predictions that are used for the determination of |Vub|. In addition, the measured dependence of the hadronic mass moments on the hadronic mass cut is compared to the dependence predicted by Heavy Quark Effective Theory.

  14. Density of saturated nuclear matter at large Nc and heavy quark mass limits

    NASA Astrophysics Data System (ADS)

    Adhikari, Prabal; Cohen, Thomas D.; Datta, Ishaun

    2014-06-01

    We exhibit the existence of stable, saturated nuclear matter in the large Nc and heavy quark mass limits of QCD. In this limit, baryons (with the same spin flavor structure) interact at leading order in Nc via a repulsive interaction due to the Pauli exclusion principle and at subleading order in 1/Nc via the exchange of glueballs. Assuming that the lightest glueball is a scalar, which implies that the subleading baryon interaction is attractive, we find that nuclear matter saturates since the subleading attractive interaction is longer ranged than the leading order repulsive one. We find that the saturated matter is in the form of a crystal with either a face-centered-cubic or a hexagonal-close-packed symmetry with baryon densities of O ({α˜smq[mass and scalar-glueball-baryon coupling in the extreme large Nc limit or heavy quark limit (or both), which we define precisely in this work.

  15. Measurement of the mass of the top quark in dilepton final states with the D0 detector

    SciTech Connect

    Brandt, Oleg; /Bonn U.

    2006-08-01

    In the Standard Model (SM) the top quark mass is a fundamental parameter. Its precise measurement is important to test the self-consistency of the SM. Additionally, it offers sensitivity to New Physics beyond the Standard Model. In proton anti-proton collisions at a centre-of-mass energy of {radical}s = 1.96 TeV t{bar t} quarks are pair-produced, each decaying into a W boson and a b quark. In the dilepton channel both W bosons decay leptonically. Because of the presence of two neutrinos in the final state the kinematics are underconstrained. A so-called Neutrino Weighting algorithm is used to calculate a weight for the consistency of a hypothesized top quark mass with the event kinematics. To render the problem solvable, the pseudorapidities of the neutrinos are assumed. The Maximum Method, which takes the maximum to the weight distribution as input to infer the top quark mass, is applied to approximately 370 pb{sup -1} of Run-II data, recorded by the D0 experiment at the Tevatron. The e{mu}-channel of the 835 pb{sup -1} dataset is analyzed.

  16. Precise measurement of the top quark mass in the dilepton channel at D0.

    PubMed

    Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Das, A; Davies, G; De, K; de Jong, S J; De la Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Guo, F; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De la Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jamin, D; Jayasinghe, A; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kulikov, S; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Padilla, M; Pal, A; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Polozov, P; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Salcido, P; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stolin, V; Stoyanova, D A; Strauss, M; Strom, D; Stutte, L; Suter, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2011-08-19

    We measure the top quark mass (m(t)) in p ̄p collisions at a center of mass energy √s = 1.96 TeV using dilepton t ̄t→W(+)bW(-) ̄b→ℓ(+)ν(ℓ)bℓ(-) ̄ν(ℓ) ̄b events, where ℓ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider. We obtain m(t)=174.0±1.8(stat)±2.4(syst) GeV, which is in agreement with the current world average m(t)=173.3±1.1 GeV. This is currently the most precise measurement of m(t) in the dilepton channel. PMID:21929164

  17. Measurement of the top quark mass in the dilepton channel using the neutrino weighting algorithm at CDF II

    NASA Astrophysics Data System (ADS)

    Sabik, Simon

    We measure the top quark mass using approximately 359 pb-1 of data from pp¯ collisions at s = 1.96 GeV at CDF Run II. We select tt¯ candidates that are consistent with two W bosons decaying to a charged lepton and a neutrino following tt¯ → W+W-bb¯ → l+l- nn¯ bb¯. Only one of the two charged leptons is required to be identified as an electron or a muon candidate, while the other is simply a well measured track. We use a neutrino weighting algorithm which weighs each possibility of neutrino direction to reconstruct a top quark mass in each event. We compare the resulting distribution to Monte Carlo templates to obtain a top quark mass of 170.8+6.9-6.5 (stat) +/- 4.6 (syst) GeV/c 2.

  18. Temperature Dependence of Decuplet Baryon Masses from Thermal QCD Sum Rules

    NASA Astrophysics Data System (ADS)

    Xu, Yong-Jiang; Liu, Yong-Lu; Huang, Ming-Qiu

    2015-02-01

    In the present work, the masses of the decuplet baryons at finite temperature are investigated using thermal QCD sum rules. Making use of the quark propagator at finite temperature, we calculate the spectral functions to T8 order, and find that there are no contributions to the spectral functions at T8 order and the temperature corrections mainly come from that containing T4 ones. The calculations show very little temperature dependence of the masses below T = 0.11 GeV. While above that value, the masses decrease with increasing temperature. The results indicate that the hadron-quark phase transition temperature may be Tc >= 0.11 GeV for the decuplet bayons.

  19. A Method for the Precision Mass Measurement of the Stop Quark at the International Linear Collider

    SciTech Connect

    Freitas, Ayres; Milstene, Caroline; Schmitt, Michael; Sopczak, Andre; /Lancaster U.

    2007-12-01

    Many supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of symmetry breaking, it is important to know the masses of the new particles precisely. In this article the measurement of the mass of the scalar partner of the top quark (stop) at an e{sup +}e{sup -} collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter relic density. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method not only increases the statistical precision, but also greatly reduces the systematic uncertainties, which can be important. numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). The studies indicate that a precision of {Delta}m{sub {bar t}{sub 1}} = 0.42 GeV can be achieved, representing a major improvement over previous studies. While the analysis of stops is particularly challenging due to the possibility of stop hadronization, the general procedure could be applied to the mass measurement of other particles as well. They also comment on the potential of the IDA to discover a stop quark in this scenario, and they revisit the accuracy of the theoretical predictions for the neutralino relic density.

  20. A Method for the Precision Mass Measurement of the Stop Quark at the International Linear Collider

    SciTech Connect

    Freitas, Ayres; Milstene, Caroline; Schmitt, Michael; Sopczak, Andre; /Lancaster U.

    2008-06-01

    Many supersymmetric models predict new particles within the reach of the next generation of colliders. For an understanding of the model structure and the mechanism(s) of symmetry breaking, it is important to know the masses of the new particles precisely. In this article the measurement of the mass of the scalar partner of the top quark (stop) at an e+e- collider is studied. A relatively light stop is motivated by attempts to explain electroweak baryogenesis and can play an important role in dark matter relic density. A method is presented which makes use of cross-section measurements near the pair-production threshold as well as at higher center-of-mass energies. It is shown that this method not only increases the statistical precision, but also greatly reduces the systematic uncertainties, which can be important. Numerical results are presented, based on a realistic event simulation, for two signal selection strategies: using conventional selection cuts, and using an Iterative Discriminant Analysis (IDA). Our studies indicate that a precision of {Delta}m{tilde t}{sub 1} = 0.42 GeV can be achieved, representing a major improvement over previous studies. While the analysis of stops is particularly challenging due to the possibility of stop hadronization, the general procedure could be applied to the mass measurement of other particles as well. We also comment on the potential of the IDA to discover a stop quark in this scenario, and we revisit the accuracy of the theoretical predictions for the neutralino relic density

  1. Extracting the Light Quark Mass Ratio m{sub u}/m{sub d} from Bottomonia Transitions

    SciTech Connect

    Guo Fengkun; Hanhart, Christoph; Meissner, Ulf-G.

    2010-10-15

    We propose a new method to extract the light quark mass ratio m{sub u}/m{sub d} using the {Upsilon}(4S){yields}h{sub b{pi}}{sup 0}({eta}) bottomonia transitions. The decay amplitudes are dominated by the light quark mass differences, and the corrections from other effects are rather small, allowing for a precise extraction. We also discuss how to reduce the theoretical uncertainty with the help of future experiments. As a by-product, we show that the decay {Upsilon}(4S){yields}h{sub b{eta}} is expected to be a nice channel for searching for the h{sub b} state.

  2. Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2008-12-01

    The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.

  3. Flavour dependent gauged radiative neutrino mass model

    NASA Astrophysics Data System (ADS)

    Baek, Seungwon; Okada, Hiroshi; Yagyu, Kei

    2015-04-01

    We propose a one-loop induced radiative neutrino mass model with anomaly free flavour dependent gauge symmetry: μ minus τ symmetry U(1) μ- τ . A neutrino mass matrix satisfying current experimental data can be obtained by introducing a weak isospin singlet scalar boson that breaks U(1) μ- τ symmetry, an inert doublet scalar field, and three right-handed neutrinos in addition to the fields in the standard model. We find that a characteristic structure appears in the neutrino mass matrix: two-zero texture form which predicts three non-zero neutrino masses and three non-zero CP-phases from five well measured experimental inputs of two squared mass differences and three mixing angles. Furthermore, it is clarified that only the inverted mass hierarchy is allowed in our model. In a favored parameter set from the neutrino sector, the discrepancy in the muon anomalous magnetic moment between the experimental data and the the standard model prediction can be explained by the additional neutral gauge boson loop contribution with mass of order 100 MeV and new gauge coupling of order 10-3.

  4. Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the regularization invariant symmetric momentum-subtraction schemes

    SciTech Connect

    Almeida, Leandro G.; Sturm, Christian

    2010-09-01

    Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction (RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the MS scheme. We calculate the two-loop corrections in QCD to these matching factors as well as the three-loop mass anomalous dimensions for the RI/SMOM and RI/SMOM{sub {gamma}{sub {mu}} }schemes. These two schemes are characterized by a symmetric subtraction point. Providing the conversion factors in the two different schemes allows for a better understanding of the systematic uncertainties. The two-loop expansion coefficients of the matching factors for both schemes turn out to be small compared to the traditional RI/MOM schemes. For n{sub f}=3 quark flavors they are about 0.6%-0.7% and 2%, respectively, of the leading order result at scales of about 2 GeV. Therefore, they will allow for a significant reduction of the systematic uncertainty of light quark mass determinations obtained through this approach. The determination of these matching factors requires the computation of amputated Green's functions with the insertions of quark bilinear operators. As a by-product of our calculation we also provide the corresponding results for the tensor operator.

  5. Two-loop matching factors for light quark masses and three-loop mass anomalous dimensions in the RI/SMOM schemes

    SciTech Connect

    Sturm, C.; Almeida, L.

    2010-04-26

    Light quark masses can be determined through lattice simulations in regularization invariant momentum-subtraction (RI/MOM) schemes. Subsequently, matching factors, computed in continuum perturbation theory, are used in order to convert these quark masses from a RI/MOM scheme to the {ovr MS} scheme. We calculate the two-loop corrections in QCD to these matching factors as well as the three-loop mass anomalous dimensions for the RI/SMOM and RI/SMOM{sub {gamma}{mu}} schemes. These two schemes are characterized by a symmetric subtraction point. Providing the conversion factors in the two different schemes allows for a better understanding of the systematic uncertainties. The two-loop expansion coefficients of the matching factors for both schemes turn out to be small compared to the traditional RI/MOM schemes. For n{sub f} = 3 quark flavors they are about 0.6%-0.7% and 2%, respectively, of the leading order result at scales of about 2 GeV. Therefore, they will allow for a significant reduction of the systematic uncertainty of light quark mass determinations obtained through this approach. The determination of these matching factors requires the computation of amputated Green's functions with the insertions of quark bilinear operators. As a by-product of our calculation we also provide the corresponding results for the tensor operator.

  6. Precision measurement of the top quark mass from dilepton events at CDF II

    SciTech Connect

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-12-01

    We report a measurement of the top quark mass, M{sub t}, in the dilepton decay channel of t{bar t} {yields} b{ell}{prime}{sup +} {nu}{sub {ell}}, {bar b}{ell}{sup -}{bar {nu}}{sub {ell}} using an integrated luminosity of 1.0 fb{sup -1} of p{bar p} collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a measurement of M{sub t} = 164.5 {+-} 3.9(stat.) {+-} 3.9(syst.) GeV/c{sup 2}, the most precise measurement of M{sub t} in the dilepton channel.

  7. A family of exact solutions of Einstein-Maxwell field equations in isotropic coordinates: an application to optimization of quark star mass

    NASA Astrophysics Data System (ADS)

    Pant, Neeraj; Pradhan, N.; Murad, Mohammad Hassan

    2014-07-01

    In the present paper, we have obtained a class of charged super dense star models, starting with a static spherically symmetric metric in isotropic coordinates for perfect fluid by considering Hajj-Boutros (in J. Math. Phys. 27:1363, 1986) type metric potential and a specific choice of electrical intensity which involves a parameter K. The resulting solutions represent charged fluid spheres joining smoothly with the Reissner-Nordstrom metric at the pressure free interface. The solutions so obtained are utilized to construct the models for super-dense star like neutron stars ( ρ b =2 and 2.7×1014 g/cm3) and Quark stars ( ρ b =4.6888×1014 g/cm3). Our solution is well behaved for all values of n satisfying the inequalities and K satisfying the inequalities 0≤ K≤0.24988, depending upon the value of n. Corresponding to n=4.001 and K=0.24988, we observe that the maximum mass of quark star M=2.335 M ⊙ and radius R=10.04 km. Further, this maximum mass limit of quark star is in the order of maximum mass of stable Strange Quark Star established by Dong et al. (in arXiv:1207.0429v3 , 2013). The robustness of our results is that the models are alike with the recent discoveries.

  8. Time-Dependence of the Survival Probability of Quarkonia in Quark-Gluon Plasma

    NASA Astrophysics Data System (ADS)

    Mah Hussin, Noor Sabrina; Shalaby, Asmaa; Petridis, Athanasios

    2015-10-01

    The time-dependent Schrödinger equation is used to study the formation of quarkonia and their propagation in Quark-Gluon Plasma (QGP). The initial bound (ground) state is computed using imaginary-time propagation in a confining potential. The QGP is simulated with a confining potential of an extended asymptotic freedom region. The interior of the QGP potential may correspond to a vacuum that differs from that of the exterior region. The initial state propagates through this potential in real time. The survival probability is calculated versus time for various potential parameters and relative momenta of the quarkonium by projecting the interacting wavefunction onto its freely-propagating counterpart. In these calculations the staggered-leap frog method is used with special attention paid to the issue of stability. It is found that quarkonium decay is typically non-exponential. Fast moving states decay faster. Connection with experimental results is done by means of cross-section ratios.

  9. Effects of dynamical masses of gluons and quarks on hadronic B decays

    SciTech Connect

    Zanetti, C. M.; Natale, A. A.

    2010-11-12

    We study hadronic annihilation decays of B mesons within the perturbative QCD at collinear approximation. The regulation of endpoint divergences is performed with the help of an infrared finite gluon propagator characterized by a non-perturbative dynamical gluon mass. The divergences at twist-3 are regulated by a dynamical quark mass. Our results fit quite well the existent data of B{sup 0}{yields}D{sub s}{sup -}K{sup +} and B{sup 0}{yields}D{sub s}{sup -*}K{sup +} for the expected range of dynamical gluon masses. We also make predictions for the rare decays B{sup 0}{yields}K{sup -}K{sup +}, B{sub s}{sup 0}{yields}{pi}{sup -}{pi}{sup +}, {pi}{sup 0}{pi}{sup 0}, B{sup +}{yields}D{sub s}{sup (*)+}K-bar{sup 0}, B{sup 0}{yields}D{sub s}{sup {+-}(*)}K{sup {+-}} and B{sub s}{sup 0}{yields}D{sup {+-}(*)}{pi}{sup {+-}}, D{sup 0}{pi}{sup 0}.

  10. CDF measurement of the top quark mass in the lepton + jets channel using the multivariate template method

    SciTech Connect

    Freeman, John; /Fermilab

    2004-12-01

    The authors measure the mass of the top quark using 162 pb{sup -1} of data collected by the CDF experiment at FNAL in Run II. The decay chain t{bar t} {yields} bq{bar q}{bar b}lv is studied using a novel technique called the Multivariate Template Method (MTM). Using this technique they obtain a result of M{sub top} = 179.6{sub -6.3}{sup +6.4} {+-} 6.8 GeV/c{sup 2} for the top quark.

  11. Renormalization of quark propagators from twisted-mass lattice QCD at N{sub f}=2

    SciTech Connect

    Blossier, B.; Boucaud, Ph.; Pene, O.; Petrov, K.; Brinet, M.; Liu, Z.; Morenas, V.

    2011-04-01

    We present results concerning the nonperturbative evaluation of the renormalization constant for the quark field, Z{sub q}, from lattice simulations with twisted-mass quarks and three values of the lattice spacing. We use the regularization-invariant momentum-subtraction (RI'-MOM) scheme. Z{sub q} has very large lattice spacing artefacts; it is considered here as a test bed to elaborate accurate methods which will be used for other renormalization constants. We recall and develop the nonperturbative correction methods and propose tools to test the quality of the correction. These tests are also applied to the perturbative correction method. We check that the lattice-spacing artefacts indeed scale as a{sup 2}p{sup 2}. We then study the running of Z{sub q} with particular attention to the nonperturbative effects, presumably dominated by the dimension-two gluon condensate in Landau gauge. We show indeed that this effect is present, and not small. We check its scaling in physical units, confirming that it is a continuum effect. It gives a {approx}4% contribution at 2 GeV. Different variants are used in order to test the reliability of our result and estimate the systematic uncertainties. Finally, combining all our results and using the known Wilson coefficient of , we find g{sup 2}({mu}{sup 2}){sub {mu}}{sup 2}{sub CM}=2.01(11)({sub -0.73}{sup +0.61})GeV{sup 2} at {mu}=10 GeV, the local operator A{sup 2} being renormalized in the MS scheme. This last result is in fair agreement within uncertainties with the value independently extracted from the strong coupling constant. We convert the nonperturbative part of Z{sub q} from the regularization-invariant momentum-subtraction (RI'-MOM) scheme to MS. Our result for the quark field renormalization constant in the MS scheme is Z{sub q} {sup MS} {sup pert}((2 GeV){sup 2},g{sub bare}{sup 2})=0.750(3)(7)-0.313(20)(g{sub bare}{sup 2}-1.5) for the perturbative contribution and Z{sub q

  12. Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at √s=7 TeV

    SciTech Connect

    Aad, G.; Abbott, B.; Abdallah, J.; Khalek, S. Abdel; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyka, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.

    2015-04-23

    In this study, the mass of the top quark is measured in a data set corresponding to 4.6 fb-1 of proton–proton collisions with centre-of-mass energy √s=7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top–antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of mt=175.1±1.4(stat.) ±1.2(syst.) GeV.

  13. Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at √s=7 TeV

    DOE PAGESBeta

    Aad, G.; Abbott, B.; Abdallah, J.; Khalek, S. Abdel; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; et al

    2015-04-23

    In this study, the mass of the top quark is measured in a data set corresponding to 4.6 fb-1 of proton–proton collisions with centre-of-mass energy √s=7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top–antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jetmore » to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of mt=175.1±1.4(stat.) ±1.2(syst.) GeV.« less

  14. Environmental dependence of masses and coupling constants

    SciTech Connect

    Olive, Keith A.; Pospelov, Maxim

    2008-02-15

    We construct a class of scalar field models coupled to matter that lead to the dependence of masses and coupling constants on the ambient matter density. Such models predict a deviation of couplings measured on the Earth from values determined in low-density astrophysical environments, but do not necessarily require the evolution of coupling constants with the redshift in the recent cosmological past. Additional laboratory and astrophysical tests of {delta}{alpha} and {delta}(m{sub p}/m{sub e}) as functions of the ambient matter density are warranted.

  15. Determination of the b-quark Mass and Nonperturbative parameters in Semileptonic and Radiative Penguin Decays at BaBar

    SciTech Connect

    Tackmann, Kerstin; collaboration, for the BABAR

    2008-01-23

    Knowing the mass of the b-quark is essential to the study of the structure and decays of B mesons as well as to future tests of the Higgs mechanism of mass generation. We present recent preliminary measurements of the b-quark mass and related nonperturbative parameters from moments of kinematic distributions in charmed and charmless semileptonic and radiative penguin B decays. Their determination from charmless semileptonic B decays is the first measurement in this mode. The data were collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -}-collider at the Stanford Linear Accelerator Center at a center-of-momentum energy of 10:58 GeV.

  16. Measurement of the top quark mass using the template method in the lepton plus jets channel with in situ W ---> j j calibration at CDF-II

    SciTech Connect

    Adelman, Jahred A.; Arguin, J.F.; Bellettini, G.; Brubaker, E.; Budagov, J.; Chlachidze, G.; Demortier, L.; Gibson, A.; Kim, S.; Kim, Y.K.; Maruyama, T.; Sato, K.; Shochet, M.; Sinervo, P.; Tomura, T.; Velev, G.; Xie, S.; Yang, U.K.; /Chicago U. /Toronto U. /INFN, Pisa /Dubna, JINR /Rockefeller U. /LBL, Berkeley /Tsukuba U. /Fermilab

    2006-05-01

    We report an updated measurement of the top quark mass in the lepton plus jets channel of t{bar t} events from p{bar p} collisions at {radical}s = 1.96 TeV. This measurement uses a dataset with integrated luminosity of 680 pb{sup -1}, containing 360 t{bar t} candidates separated into four subsamples. A top quark mass is reconstructed for each event by using energy and momentum constraints on the top quark pair decay products. We also employ the reconstructed mass of hadronic W boson decays W {yields} jj to constrain in situ the largest systematic uncertainty of the top quark mass measurement: the jet energy scale. Monte Carlo templates of the reconstructed top quark and W boson mass are produced as a function of the true top quark mass and the jet energy scale. The distribution of reconstructed top quark and W boson mass in the data are compared to the Monte Carlo templates using a likelihood fit to obtain: M{sub top} = 173.4 {+-} 2.8 GeV/c{sup 2}.

  17. Initial conditions dependency in heavy-quarks suppression in ultra-relativistic collisions

    SciTech Connect

    Alves Garcia Prado, Caio; Alarcon do Passo Suaide, Alexandre

    2013-05-06

    Heavy quark suppression in central Au+Au collisions is expected to be smaller than that of light quarks. However experimental data suggest that they are evenly suppressed. We propose considering fluctuations in the medium as they may lead to high-density regions which in turn can cause a considerable quark suppression at the early stages of the collision evolution. To analyse the overall effect of these fluctuations we perform computer simulations of charm and bottom propagating through the quark-gluon plasma and obtain estimates of the nuclear modification factor R{sub AA}. This quantity gives us information about the heavy quark suppression that can be compared to published experimental data from the STAR experiment.

  18. Time-Dependent Dynamics of Massive Quarkonium Resonances in Nuclear and Quark-Gluon-Plasma Media

    NASA Astrophysics Data System (ADS)

    Mah Hussin, Noor Sabrina; Shalaby, Asmaa; Petridis, Athanasios

    2014-03-01

    The time-dependent Schrödinger equation is used to study the formation of quarkonia and their propagation in Quark-Gluon Plasma (QGP) and nuclear media. The initial bound (ground) state is computed using imaginary-time propagation in a confining potential. The QGP is simulated with a confining potential of an extended asymptotic freedom region. The initial state propagates through this potential in real time. The nuclear medium is simulated with a periodic potential. In all cases the survival probability is calculated versus time for various potential parameters and relative momenta of the quarkonium with respect to the surrounding medium. In all calculations the staggered-leap frog method is used with special attention paid to the issue of stability. It is found that quarkonium decay is typically non-exponential. Fast moving states decay faster. There is a distinctive difference in the time-dependence of the survival probability between QGP and the nuclear medium. The effects of more realistic potentials are investigated.

  19. Top Quark Mass Measurement in the t anti-t All Hadronic Channel using a Matrix Element Technique in p anti-p Collisions at s**91/2) = 1.96-TeV

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, J.; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.

    2008-11-01

    We present a measurement of the top quark mass in the all-hadronic channel (t{bar t} {yields} b{bar b} q{sub 1}{bar q}{sub 2}q{sub 3}{bar q}{sub 4}) using 943 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected at the CDF II detector at Fermilab (CDF). We apply the standard model production and decay matrix-element (ME) to t{bar t} candidate events. We calculate per-event probability densities according to the ME calculation and construct template models of signal and background. The scale of the jet energy is calibrated using additional templates formed with the invariant mass of pairs of jets. These templates form an overall likelihood function that depends on the top quark mass and on the jet energy scale (JES). We estimate both by maximizing this function. Given 72 observed events, we measure a top quark mass of 171.1 {+-} 3.7 (stat.+JES) {+-} 2.1 (syst.) GeV/c{sup 2}. The combined uncertainty on the top quark mass is 4.3 GeV/c{sup 2}.

  20. Measurement of the top quark mass with a matrix element method in the lepton plus jets channel at CDF

    SciTech Connect

    Mohr, Brian; /UCLA

    2006-05-01

    The authors present a measurement of the mass of the top quark from p{bar p} collisions at 1.96 TeV observed with the Collider Detector at Fermilab (CDF) at the Fermilab Tevatron Run II. The events have the decay signature of p{bar p} {yields} t{bar t} in the lepton plus jets channel in which at least one jet is identified as coming from a secondary vertex and therefore a b-hadron. The largest systematic uncertainty, the jet energy scale (JES), is convoluted with the statistical error using an in-situ measurement of the hadronic W boson mass. They calculate a likelihood for each event using leading-order t{bar t} and W+jets cross-sections and parameterized parton showering. The final measured top quark mass and JES systematic is extracted from a joint likelihood of the product of individual event likelihoods. From 118 events observed in 680 pb{sup -1} of data, they measure a top quark mass of 174.09 {+-} 2.54 (stat+JES) {+-} 1.35(syst) GeV/c{sup 2}.

  1. Renormalization of quark propagator, vertex functions, and twist-2 operators from twisted-mass lattice QCD at Nf=4

    NASA Astrophysics Data System (ADS)

    Blossier, Benoît.; Brinet, Mariane; Guichon, Pierre; Morénas, Vincent; Pène, Olivier; Rodríguez-Quintero, Jose; Zafeiropoulos, Savvas

    2015-06-01

    We present a precise nonperturbative determination of the renormalization constants in the mass independent RI'-MOM scheme. The lattice implementation uses the Iwasaki gauge action and four degenerate dynamical twisted-mass fermions. The gauge configurations are provided by the ETM Collaboration. Renormalization constants for scalar, pseudoscalar, vector and axial operators, as well as the quark propagator renormalization, are computed at three different values of the lattice spacing, two volumes and several twisted-mass parameters. The method we developed allows for a precise cross-check of the running, thanks to the particular proper treatment of hypercubic artifacts. Results for the twist-2 operator O44 are also presented.

  2. Determination of light quark masses from {eta}{yields}3{pi}{sup 0}

    SciTech Connect

    Deandrea, A.; Talavera, P.

    2008-08-01

    We provide a model-independent determination of the quantity B{sub 0}(m{sub d}-m{sub u}). Our approach rests only on chiral symmetry and data from the decay of the eta into three neutral pions. Since the low-energy prediction at next-to-leading order fails to reproduce the experimental results, we keep the strong interaction correction as an unknown parameter. As a first step, we relate this parameter to the quark mass difference using data from the Dalitz plot. A similar relation is obtained using data from the decay width. Combining both relations we obtain B{sub 0}(m{sub d}-m{sub u})=(4495{+-}440) MeV{sup 2}. The preceding value, combined with lattice determinations, leads to the values m{sub u}(2 GeV)=(2.9{+-}0.8) MeV and m{sub d}(2 GeV)=(4.7{+-}0.8) MeV.

  3. Light-quark mass behaviour of the X(3872) as a molecular state

    NASA Astrophysics Data System (ADS)

    Baru, V.; Epelbaum, E.; Filin, A. A.; Gegelia, J.; Nefediev, A. V.

    2016-03-01

    Chiral extrapolations of the binding energy of the X(3872) molecular state are investigated using an explicitly renormalizable framework free of finite cut-off artefacts. Insights into the binding mechanisms are discussed: if the X is less bound with the growing pion mass, its binding energy is governed by the explicit pion mass dependence from one-pion exchange; an opposite behaviour would indicate the importance of the pionmass dependent short-range interactions, in addition to pionic effects. The important role of the three-body DD¯π dynamics is emphasised.

  4. Measurement of the top-quark mass in all-hadronic decays in p anti-p collisions at CDF II

    SciTech Connect

    Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Fermilab /Frascati

    2006-12-01

    We present a measurement of the top-quark mass, M{sub tpo}, in the all-hadronic decay channel t{bar t} {yields} W{sup +}bW{sup -}{bar b} {yields} q{sub 1}{bar q}{sub 2}bq{sub 3}{bar q}{sub 4}{bar b}. The analysis is performed using 310 pb{sup -1} of {radical}s = 1.96 TeV p{bar p} collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of M{sub top} = 177.1 {+-} 4.9(stat.) {+-} 4.7(syst.) GeV/c{sup 2}.

  5. Precision measurement of the top quark mass in the lepton + jets channel using a matrix element method with Quasi-Monte Carlo integration

    SciTech Connect

    Lujan, Paul Joseph

    2009-12-01

    This thesis presents a measurement of the top quark mass obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. The measurement uses a matrix element integration method to calculate a t$\\bar{t}$ likelihood, employing a Quasi-Monte Carlo integration, which enables us to take into account effects due to finite detector angular resolution and quark mass effects. We calculate a t$\\bar{t}$ likelihood as a 2-D function of the top pole mass mt and ΔJES, where ΔJES parameterizes the uncertainty in our knowledge of the jet energy scale; it is a shift applied to all jet energies in units of the jet-dependent systematic error. By introducing ΔJES into the likelihood, we can use the information contained in W boson decays to constrain ΔJES and reduce error due to this uncertainty. We use a neural network discriminant to identify events likely to be background, and apply a cut on the peak value of individual event likelihoods to reduce the effect of badly reconstructed events. This measurement uses a total of 4.3 fb-1 of integrated luminosity, requiring events with a lepton, large ET, and exactly four high-energy jets in the pseudorapidity range |η| < 2.0, of which at least one must be tagged as coming from a b quark. In total, we observe 738 events before and 630 events after applying the likelihood cut, and measure mt = 172.6 ± 0.9 (stat.) ± 0.7 (JES) ± 1.1 (syst.) GeV/c2, or mt = 172.6 ± 1.6 (tot.) GeV/c2.

  6. Measurement of the Inclusive Forward-Backward top quark-antitop quark Production Asymmetry and its Rapidity Dependence dAfb/d(delta y)

    NASA Astrophysics Data System (ADS)

    Strycker, Glenn Lloyd

    Early measurements of a large forward-background asymmetry at the CDF [1, 2, 3, 4] and Dempty [5, 6] experiments at Fermilab have generated much recent interest, but were hampered by large uncertainties. We present here a new measurement of the corrected forward-backward asymmetry of pair-produced top quarks, using a high-statistics sample with much improved precision. We study the rapidity, ytop, of the top quark production angle with respect to the incoming parton momentum in both the lab and tt¯ rest frames. We find the corrected forward-backward asymmetries to be Appfb=0.150+/- 0.050stat+/-0.024syst Attfb=0.158+/-0 .072stat+/-0.024syst These results should be compared with the small lab pp¯ frame charge asymmetry expected in QCD at NLO, Afb = 0.050 +/- 0.015 [7, 8, 9, 10]. Additionally, we introduce a measurement of the A fb rapidity dependence dAfbd Dy . We find this to be Attfb Dy<1.0 =0.026+/-0.104stat+/-0.012 syst Attfb Dy>1.0=0.6 11+/-0.210stat+/-0.246syst which we compare with model predictions 0.039 +/- 0.006 and 0.123 +/- 0.018 for the inner and outer rapidities, respectively.

  7. QCD quark condensate in external magnetic fields

    NASA Astrophysics Data System (ADS)

    Bali, G. S.; Bruckmann, F.; Endrődi, G.; Fodor, Z.; Katz, S. D.; Schäfer, A.

    2012-10-01

    We present a comprehensive analysis of the light condensates in QCD with 1+1+1 sea quark flavors (with mass-degenerate light quarks of different electric charges) at zero and nonzero temperatures of up to 190 MeV and external magnetic fields B<1GeV2/e. We employ stout smeared staggered fermions with physical quark masses and extrapolate the results to the continuum limit. At low temperatures we confirm the magnetic catalysis scenario predicted by many model calculations while around the crossover the condensate develops a complex dependence on the external magnetic field, resulting in a decrease of the transition temperature.

  8. Determination of light quark masses from the electromagnetic splitting of pseudoscalar meson masses computed with two flavors of domain wall fermions

    SciTech Connect

    Blum, Thomas; Doi, Takumi; Hayakawa, Masashi; Izubuchi, Taku; Yamada, Norikazu

    2007-12-01

    We determine the light quark masses from lattice QCD simulations incorporating the electromagnetic interaction of valence quarks, using the splittings of charged and neutral pseudoscalar meson masses as inputs. The meson masses are calculated on lattice QCD configurations generated by the RBC Collaboration for two flavors of dynamical domain-wall fermions, which are combined with QED configurations generated via quenched noncompact lattice QED. The electromagnetic part of the pion mass splitting is found to be m{sub {pi}{sup +}}-m{sub {pi}{sup 0}}=4.12(21) MeV, where only the statistical error is quoted, and similarly for the kaon, 1.443(55) MeV. Our results for the light quark masses are m{sub u}{sup MS}(2 GeV)=3.02(27)(19) MeV, m{sub d}{sup MS}(2 GeV)=5.49(20)(34) MeV, and m{sub s}{sup MS}(2 GeV)=119.5(56)(74) MeV, where the first error is statistical and the second reflects the uncertainty in our nonperturbative renormalization procedure. By averaging over {+-}e to cancel O(e) noise exactly on each combined gauge field configuration, we are able to work at physical {alpha}=1/137 and obtain very small statistical errors. In our calculation, several sources of systematic error remain, including finite volume, nonzero lattice spacing, chiral extrapolation, quenched QED, and quenched strange quark, which may be more significant than the errors quoted above. We discuss these systematic errors and how to reduce or eliminate them.

  9. Measurement of the top quark mass using charged particles in p p collisions at √{s }=8 TeV

    NASA Astrophysics Data System (ADS)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rad, N.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moortgat, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Schöfbeck, R.; Sigamani, M.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Ceard, L.; De Visscher, S.; Delaere, C.; Delcourt, M.; Forthomme, L.; Francois, B.; Giammanco, A.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Nuttens, C.; Piotrzkowski, K.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hamer, M.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; De Souza Santos, A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Leggat, D.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Finger, M.; Finger, M.; Carrera Jarrin, E.; Awad, A.; Elgammal, S.; Mohamed, A.; Salama, E.; Calpas, B.; Kadastik, M.; Murumaa, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Peltola, T.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Abdulsalam, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Davignon, O.; Dobrzynski, L.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Merlin, J. A.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Bouvier, E.

    2016-05-01

    A novel technique for measuring the mass of the top quark that uses only the kinematic properties of its charged decay products is presented. Top quark pair events with final states with one or two charged leptons and hadronic jets are selected from the data set of 8 TeV proton-proton collisions, corresponding to an integrated luminosity of 19.7 fb-1 . By reconstructing secondary vertices inside the selected jets and computing the invariant mass of the system formed by the secondary vertex and an isolated lepton, an observable is constructed that is sensitive to the top quark mass that is expected to be robust against the energy scale of hadronic jets. The main theoretical systematic uncertainties, concerning the modeling of the fragmentation and hadronization of b quarks and the reconstruction of secondary vertices from the decays of b hadrons, are studied. A top quark mass of 173.68 ±0.20 (stat)-0.97 +1.58(syst ) GeV is measured. The overall systematic uncertainty is dominated by the uncertainty in the b quark fragmentation and the modeling of kinematic properties of the top quark.

  10. Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Majersky, O.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.

    2016-06-01

    We report a measurement of the forward-backward asymmetry, AFB , in b b ¯ pairs produced in proton-antiproton collisions and identified by muons from semileptonic b -hadron decays. The event sample is collected at a center-of-mass energy of √{s }=1.96 TeV with the CDF II detector and corresponds to 6.9 fb-1 of integrated luminosity. We obtain an integrated asymmetry of AFB(b b ¯ ) =(1.2 ±0.7 )% at the particle level for b -quark pairs with invariant mass, mb b ¯ , down to 40 GeV /c2 and measure the dependence of AFB(b b ¯ ) on mb b ¯ . The results are compatible with expectations from the standard model.

  11. Measurement of the forward-backward asymmetry in low-mass bottom-quark pairs produced in proton-antiproton collisions

    DOE PAGESBeta

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; et al

    2016-06-02

    Here, we report a measurement of the forward-backward asymmetry, AFB, in bb¯ pairs produced in proton-antiproton collisions and identified by muons from semileptonic b-hadron decays. The event sample is collected at a center-of-mass energy of √s = 1.96 TeV with the CDF II detector and corresponds to 6.9 fb–1 of integrated luminosity. We obtain an integrated asymmetry of AFB(bb¯)=(1.2±0.7)% at the particle level for b-quark pairs with invariant mass, mbb¯, down to 40 GeV/c2 and measure the dependence of AFB(bb¯) on mbb¯. The results are compatible with expectations from the standard model.

  12. Massive Compact Stars as Quark Stars

    NASA Astrophysics Data System (ADS)

    Rodrigues, Hilário; Barbosa Duarte, Sérgio; de Oliveira, José Carlos T.

    2011-03-01

    High-mass compact stars have been reported recently in the literature, providing strong constraints on the properties of the ultra dense matter beyond the saturation nuclear density. In view of these results, the calculations of quark star or hybrid star equilibrium structure must be compatible with the provided observational data. But since the equations of state used in describing quark matter are in general too soft in comparison with the equation of states used to describe the hadronic or nuclear matter, the calculated quark star models presented in the literature are in general not suitable to explain the stability of highly-compact massive objects. In this work, we present the calculations of a spherically symmetric quark star structure by using an equation of state that takes into account the superconducting color-flavor locked phase of the strange quark matter. In addition, some fundamental aspects of QCD (asymptotic freedom and confinement) are considered by means of a phenomenological description of the deconfined quark phase, the density-dependent quark mass model. The quark matter behavior introduced by this model stiffens the corresponding equation of state. We thus investigate the influence of this model on the mass-radius diagram of quark stars. We obtain massive quark stars due to the stiffness of the equation of state, when a reasonable parameterization of the color superconducting gap is used. Models of quark stars enveloped by a nucleonic crust composed of a nuclear lattice embedded in an electron gas, with nuclei close to neutron drip line, are also discussed.

  13. Scalar correlations in a quark plasma and low mass dilepton production

    SciTech Connect

    Blaschke, D.; Kalinovsky, Y.L.; Schmidt, S.; Schulze, H.

    1998-01-01

    We investigate possible consequences of resonant scalar interactions for dilepton production from a quark plasma at the chiral phase transition. It is found that this production mechanism is strongly suppressed compared to the Born process and has no significance for present experiments. {copyright} {ital 1998} {ital The American Physical Society}

  14. Measurement of top quark mass in the all hadronic channel in √s = 1.96 TeF, p$\\bar{p}$ collisions at D0

    SciTech Connect

    Lam, David Wai Kui

    2008-04-01

    A measurement of the top quark mass in proton-antiproton collisions at √s = 1.96 TeV using 1040fb-1 of data collected in D detector at Fermilab is presented. This analysis focuses on the all-hadronic decay mode of the top quark and therefore only events with six or more calorimeter jets in the final state are considered.

  15. The relation between the fundamental scale controlling high-energy interactions of quarks and the proton mass

    SciTech Connect

    Deur, Alexandre; Brodsky, Stanley J.; de Teramond, Guy F.

    2015-04-06

    Quantum Chromodynamics (QCD) provides a fundamental description of the physics binding quarks into protons, neutrons, and other hadrons. QCD is well understood at short distances where perturbative calculations are feasible. Establishing an explicit relation between this regime and the large-distance physics of quark confinement has been a long-sought goal. A major challenge is to relate the parameter Λs, which controls the predictions of perturbative QCD (pQCD) at short distances, to the masses of hadrons. Here we show how new theoretical insights into QCD's behavior at large and small distances lead to an analytical relation between hadronic masses and Λs. The resulting prediction, Λs = 0.341 ± 0.024 GeV agrees well with the experimental value 0.339 ± 0.016 GeV. Conversely, the experimental value of Λs can be used to predict the masses of hadrons, a task which had so far only been accomplished through intensive numerical lattice calculations, requiring several phenomenological input parameters.

  16. Broken valence chiral symmetry and chiral polarization of Dirac spectrum in Nf=12 QCD at small quark mass

    NASA Astrophysics Data System (ADS)

    Alexandru, Andrei; Horváth, Ivan

    2016-01-01

    The validity of recently proposed equivalence between valence spontaneous chiral symmetry breaking (vSChSB) and chiral polarization of low energy Dirac spectrum (ChP) in SU(3) gauge theory, is examined for the case of twelve mass-degenerate fundamental quark flavors. We find that the vSChSB-ChP correspondence holds for regularized systems studied. Moreover, our results suggest that vSChSB occurs in two qualitatively different circumstances: there is a quark mass mc such that for m > mc the mode condensing Dirac spectrum exhibits standard monotonically increasing density, while for mch < m < mc the peak around zero separates from the bulk of the spectrum, with density showing a pronounced depletion at intermediate scales. Valence chiral symmetry restoration may occur at yet smaller masses m < mch, but this has not yet been seen by overlap valence probe, leaving the mch = 0 possibility open. The latter option could place massless Nf=12 theory outside of conformal window. Anomalous behavior of overlap Dirac spectrum for mch < m < mc is qualitatively similar to one observed previously in zero and few-flavor theories as an effect of thermal agitation.

  17. Measurement of the top quark mass with the template method in the tbar{t} tolepton+jets channel using ATLAS data

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdelalim, A. A.; Abdesselam, A.; Abdinov, O.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acerbi, E.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Aderholz, M.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Akdogan, T.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Akiyama, A.; Alam, M. S.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Aliyev, M.; Allbrooke, B. M. M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral, P.; Amelung, C.; Ammosov, V. V.; Amorim, A.; Amorós, G.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Andrieux, M.-L.; Anduaga, X. S.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnault, C.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asfandiyarov, R.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astbury, A.; Astvatsatourov, A.; Aubert, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Avramidou, R.; Axen, D.; Ay, C.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Badescu, E.; Bagnaia, P.; Bahinipati, S.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barashkou, A.; Barbaro Galtieri, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beare, B.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Begel, M.; Behar Harpaz, S.; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellina, F.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Ben Ami, S.; Benary, O.; Benchekroun, D.; Benchouk, C.; Bendel, M.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertella, C.; Bertin, A.; Bertinelli, F.; Bertolucci, F.; Besana, M. I.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bitenc, U.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blazek, T.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. B.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bona, M.; Bondarenko, V. G.; Bondioli, M.; Boonekamp, M.; Booth, C. N.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Botterill, D.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozhko, N. I.; Bozovic-Jelisavcic, I.; Bracinik, J.; Braem, A.; Branchini, P.; Brandenburg, G. W.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brelier, B.; Bremer, J.; Brenner, R.; Bressler, S.; Breton, D.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Brodbeck, T. J.; Brodet, E.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, W. K.; Brown, G.; Brown, H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buat, Q.; Bucci, F.; Buchanan, J.; Buchanan, N. J.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Budick, B.; Büscher, V.; Bugge, L.; Bulekov, O.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C. P.; Butin, F.; Butler, B.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Buttinger, W.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Caloi, R.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarri, P.; Cambiaghi, M.; Cameron, D.; Caminada, L. M.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Capasso, L.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capriotti, D.; Capua, M.; Caputo, R.; Caramarcu, C.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, B.; Caron, S.; Carrillo Montoya, G. D.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castaneda Hernandez, A. M.; Castaneda-Miranda, E.; Castillo Gimenez, V.; Castro, N. F.; Cataldi, G.; Cataneo, F.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caughron, S.; Cauz, D.; Cavalleri, P.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cetin, S. A.; Cevenini, F.; Chafaq, A.; Chakraborty, D.; Chan, K.; Chapleau, B.; Chapman, J. D.; Chapman, J. W.; Chareyre, E.; Charlton, D. G.; Chavda, V.; Chavez Barajas, C. A.; Cheatham, S.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, T.; Chen, X.; Cheng, S.; Cheplakov, A.; Chepurnov, V. F.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Cheung, S. L.; Chevalier, L.; Chiefari, G.; Chikovani, L.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chizhov, M. V.; Choudalakis, G.; Chouridou, S.; Christidi, I. A.; Christov, A.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Ciapetti, G.; Ciba, K.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciobotaru, M. D.; Ciocca, C.; Ciocio, A.; Cirilli, M.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Cleland, W.; Clemens, J. C.; Clement, B.; Clement, C.; Clifft, R. W.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coe, P.; Cogan, J. G.; Coggeshall, J.; Cogneras, E.; Colas, J.; Colijn, A. P.; Collins, N. J.; Collins-Tooth, C.; Collot, J.; Colon, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Consonni, M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conventi, F.; Cook, J.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Costin, T.; Côté, D.; Coura Torres, R.; Courneyea, L.; Cowan, G.; Cowden, C.; Cox, B. E.; Cranmer, K.; Crescioli, F.; Cristinziani, M.; Crosetti, G.; Crupi, R.; Crépé-Renaudin, S.; Cuciuc, C.-M.; Cuenca Almenar, C.; Cuhadar Donszelmann, T.; Curatolo, M.; Curtis, C. J.; Cuthbert, C.; Cwetanski, P.; Czirr, H.; Czodrowski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; Da Silva, P. V. M.; Da Via, C.; Dabrowski, W.; Dai, T.; Dallapiccola, C.; Dam, M.; Dameri, M.; Damiani, D. S.; Danielsson, H. O.; Dannheim, D.; Dao, V.; Darbo, G.; Darlea, G. L.; Davey, W.; Davidek, T.; Davidson, N.; Davidson, R.; Davies, E.; Davies, M.; Davison, A. R.; Davygora, Y.; Dawe, E.; Dawson, I.; Dawson, J. W.; Daya-Ishmukhametova, R. K.; De, K.; de Asmundis, R.; De Castro, S.; De Castro Faria Salgado, P. E.; De Cecco, S.; de Graat, J.; De Groot, N.; de Jong, P.; De La Taille, C.; De la Torre, H.; De Lotto, B.; de Mora, L.; De Nooij, L.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; Dean, S.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Degenhardt, J.; Dehchar, M.; Del Papa, C.; Del Peso, J.; Del Prete, T.; Delemontex, T.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delruelle, N.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demirkoz, B.; Deng, J.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Devetak, E.; Deviveiros, P. O.; Dewhurst, A.; DeWilde, B.; Dhaliwal, S.; Dhullipudi, R.; Di Ciaccio, A.; Di Ciaccio, L.; Di Girolamo, A.; Di Girolamo, B.; Di Luise, S.; Di Mattia, A.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Diaz, M. A.; Diblen, F.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, J.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; do Vale, M. A. B.; Do Valle Wemans, A.; Doan, T. K. 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S.; Poppleton, A.; Portell Bueso, X.; Posch, C.; Pospelov, G. E.; Pospisil, S.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Prabhu, R.; Pralavorio, P.; Pranko, A.; Prasad, S.; Pravahan, R.; Prell, S.; Pretzl, K.; Pribyl, L.; Price, D.; Price, J.; Price, L. E.; Price, M. J.; Prieur, D.; Primavera, M.; Prokofiev, K.; Prokoshin, F.; Protopopescu, S.; Proudfoot, J.; Prudent, X.; Przybycien, M.; Przysiezniak, H.; Psoroulas, S.; Ptacek, E.; Pueschel, E.; Purdham, J.; Purohit, M.; Puzo, P.; Pylypchenko, Y.; Qian, J.; Qian, Z.; Qin, Z.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Quinonez, F.; Raas, M.; Radescu, V.; Radics, B.; Radloff, P.; Rador, T.; Ragusa, F.; Rahal, G.; Rahimi, A. M.; Rahm, D.; Rajagopalan, S.; Rammensee, M.; Rammes, M.; Randle-Conde, A. S.; Randrianarivony, K.; Ratoff, P. N.; Rauscher, F.; Raymond, M.; Read, A. L.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Reichold, A.; Reinherz-Aronis, E.; Reinsch, A.; Reisinger, I.; Reljic, D.; Rembser, C.; Ren, Z. L.; Renaud, A.; Renkel, P.; Rescigno, M.; Resconi, S.; Resende, B.; Reznicek, P.; Rezvani, R.; Richards, A.; Richter, R.; Richter-Was, E.; Ridel, M.; Rijpstra, M.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Rios, R. R.; Riu, I.; Rivoltella, G.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robinson, M.; Robson, A.; Rocha de Lima, J. G.; Roda, C.; Roda Dos Santos, D.; Rodriguez, D.; Roe, A.; Roe, S.; Røhne, O.; Rojo, V.; Rolli, S.; Romaniouk, A.; Romano, M.; Romanov, V. M.; Romeo, G.; Romero Adam, E.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, A.; Rose, M.; Rosenbaum, G. A.; Rosenberg, E. I.; Rosendahl, P. L.; Rosenthal, O.; Rosselet, L.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubinskiy, I.; Ruckert, B.; Ruckstuhl, N.; Rud, V. I.; Rudolph, C.; Rudolph, G.; Rühr, F.; Ruggieri, F.; Ruiz-Martinez, A.; Rumiantsev, V.; Rumyantsev, L.; Runge, K.; Rurikova, Z.; Rusakovich, N. A.; Rust, D. R.; Rutherfoord, J. P.; Ruwiedel, C.; Ruzicka, P.; Ryabov, Y. F.; Ryadovikov, V.; Ryan, P.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Rzaeva, S.; Saavedra, A. F.; Sadeh, I.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B. M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Samset, B. H.; Sanchez, A.; Sanchez Martinez, V.; Sandaker, H.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, T.; Sandoval, C.; Sandstroem, R.; Sandvoss, S.; Sankey, D. P. C.; Sansoni, A.; Santamarina Rios, C.; Santoni, C.; Santonico, R.; Santos, H.; Saraiva, J. G.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarri, F.; Sartisohn, G.; Sasaki, O.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Sauvan, E.; Sauvan, J. B.; Savard, P.; Savinov, V.; Savu, D. O.; Sawyer, L.; Saxon, D. H.; Says, L. P.; Sbarra, C.; Sbrizzi, A.; Scallon, O.; Scannicchio, D. A.; Scarcella, M.; Schaarschmidt, J.; Schacht, P.; Schäfer, U.; Schaepe, S.; Schaetzel, S.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Schamov, A. G.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schioppa, M.; Schlenker, S.; Schlereth, J. L.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitz, M.; Schöning, A.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schroeder, C.; Schroer, N.; Schuh, S.; Schuler, G.; Schultens, M. J.; Schultes, J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, J. W.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwemling, Ph.; Schwienhorst, R.; Schwierz, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Scott, W. G.; Searcy, J.; Sedov, G.; Sedykh, E.; Segura, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Selbach, K. E.; Seliverstov, D. M.; Sellden, B.; Sellers, G.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Seuster, R.; Severini, H.; Sevior, M. E.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shank, J. T.; Shao, Q. T.; Shapiro, M.; Shatalov, P. B.; Shaver, L.; Shaw, K.; Sherman, D.; Sherwood, P.; Shibata, A.; Shichi, H.; Shimizu, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Sicho, P.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simmons, B.; Simonyan, M.; Sinervo, P.; Sinev, N. 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A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staude, A.; Stavina, P.; Stavropoulos, G.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stevenson, K.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Strachota, P.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strang, M.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Strube, J.; Stugu, B.; Stumer, I.; Stupak, J.; Sturm, P.; Styles, N. A.; Soh, D. A.; Su, D.; Subramania, HS.; Succurro, A.; Sugaya, Y.; Sugimoto, T.; Suhr, C.; Suita, K.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Sushkov, S.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Suzuki, Y.; Svatos, M.; Sviridov, Yu. M.; Swedish, S.; Sykora, I.; Sykora, T.; Szeless, B.; Sánchez, J.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A.; Tamsett, M. C.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanaka, Y.; Tanasijczuk, A. J.; Tani, K.; Tannoury, N.; Tappern, G. P.; Tapprogge, S.; Tardif, D.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tassi, E.; Tatarkhanov, M.; Tayalati, Y.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teinturier, M.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Terada, S.; Terashi, K.; Terron, J.; Testa, M.; Teuscher, R. J.; Thadome, J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thioye, M.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, A. S.; Thomson, E.; Thomson, M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Y. A.; Timoshenko, S.; Tipton, P.; Tique Aires Viegas, F. J.; Tisserant, S.; Toczek, B.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokunaga, K.; Tokushuku, K.; Tollefson, K.; Tomoto, M.; Tompkins, L.; Toms, K.; Tong, G.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torchiani, I.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Trinh, T. N.; Tripiana, M. F.; Trischuk, W.; Trivedi, A.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Turala, M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Tzanakos, G.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Underwood, D. G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valenta, J.; Valente, P.; Valentinetti, S.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; van der Graaf, H.; van der Kraaij, E.; Van Der Leeuw, R.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Kesteren, Z.; van Vulpen, I.; Vanadia, M.; Vandelli, W.; Vandoni, G.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Varela Rodriguez, F.; Vari, R.; Varnes, E. W.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vegni, G.; Veillet, J. J.; Vellidis, C.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinek, E.; Vinogradov, V. B.; Virchaux, M.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vlasov, N.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Loeben, J.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorobiev, A. P.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T. T.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Wagner, W.; Wagner, P.; Wahlen, H.; Wakabayashi, J.; Walbersloh, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, J. C.; Wang, R.; Wang, S. M.; Warburton, A.; Ward, C. P.; Warsinsky, M.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. 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L.; Wu, X.; Wu, Y.; Wulf, E.; Wunstorf, R.; Wynne, B. M.; Xella, S.; Xiao, M.; Xie, S.; Xie, Y.; Xu, C.; Xu, D.; Xu, G.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamaoka, J.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U. K.; Yang, Y.; Yang, Y.; Yang, Z.; Yanush, S.; Yao, Y.; Yasu, Y.; Ybeles Smit, G. V.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Young, C.; Youssef, S.; Yu, D.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaets, V. G.; Zaidan, R.; Zaitsev, A. M.; Zajacova, Z.; Zanello, L.; Zarzhitsky, P.; Zaytsev, A.; Zeitnitz, C.; Zeller, M.; Zeman, M.; Zemla, A.; Zendler, C.; Zenin, O.; Ženiš, T.; Zinonos, Z.; Zenz, S.; Zerwas, D.; Zevi della Porta, G.; Zhan, Z.; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, X.; Zhang, Z.; Zhao, L.; Zhao, T.; Zhao, Z.; Zhemchugov, A.; Zheng, S.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zieminska, D.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; Zolnierowski, Y.; Zsenei, A.; zur Nedden, M.; Zutshi, V.; Zwalinski, L.

    2012-06-01

    The top quark mass has been measured using the template method in the tbar{t}tolepton+jets channel based on data recorded in 2011 with the ATLAS detector at the LHC. The data were taken at a proton-proton centre-of-mass energy of √{s}=7 TeV and correspond to an integrated luminosity of 1.04 fb-1. The analyses in the e+jets and μ+jets decay channels yield consistent results. The top quark mass is measured to be m top=174.5±0.6stat±2.3syst GeV.

  18. Quark matter in an SU(3) Nambu-Jona-Lasinio model with two types of vector interactions

    NASA Astrophysics Data System (ADS)

    Chu, Peng-Cheng; Wang, Bin; Ma, Hong-Yang; Dong, Yu-Min; Chang, Su-Ling; Zheng, Chun-Hong; Liu, Jun-Ting; Zhang, Xiao-Min

    2016-05-01

    We investigate the properties of asymmetric quark matter and strange quark matter in the framework of the SU(3) Nambu-Jona-Lasinio (NJL) model with two types of vector interactions: (1) the flavor-dependent repulsion among different flavors of quarks with the coupling constant GV , and (2) the universal repulsion and the vector-isovector interaction among different flavors of quarks with the coupling constants gV and GI V. Using these two types of vector interactions in the NJL model, we study the quark symmetry energy in asymmetric quark matter, the constituent quark mass, the quark fraction, the equation of state in strange quark matter, the maximum mass of a quark star, and the properties of the QCD phase diagram. We find that including the two types of vector interactions in the SU(3) NJL model can significantly influence the quark matter symmetry energy as well as the properties of strange quark matter and quark stars. In particular, our results indicate that we can describe PSR J 1614 -2230 and PSR J 0348 +0432 as quark stars by considering the universal repulsion and the vector-isovector interaction among quark matter in the SU(3) NJL model.

  19. Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Arslan, O.; Aushev, V.; Aushev, Y.; Bachynska, O.; Barakbaev, A. N.; Bartosik, N.; Behnke, O.; Behr, J.; Behrens, U.; Bertolin, A.; Bhadra, S.; Bloch, I.; Bokhonov, V.; Boos, E. G.; Borras, K.; Brock, I.; Brugnera, R.; Bruni, A.; Brzozowska, B.; Bussey, P. J.; Caldwell, A.; Capua, M.; Catterall, C. D.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cooper-Sarkar, A. M.; Corradi, M.; Corriveau, F.; D'Agostini, G.; Dementiev, R. K.; Devenish, R. C. E.; Dolinska, G.; Drugakov, V.; Dusini, S.; Ferrando, J.; Figiel, J.; Foster, B.; Gach, G.; Garfagnini, A.; Geiser, A.; Gizhko, A.; Gladilin, L. K.; Gogota, O.; Golubkov, Yu. A.; Grebenyuk, J.; Gregor, I.; Grzelak, G.; Gueta, O.; Guzik, M.; Hain, W.; Hartner, G.; Hochman, D.; Hori, R.; Ibrahim, Z. A.; Iga, Y.; Ishitsuka, M.; Iudin, A.; Januschek, F.; Kadenko, I.; Kananov, S.; Kanno, T.; Karshon, U.; Kaur, M.; Kaur, P.; Khein, L. A.; Kisielewska, D.; Klanner, R.; Klein, U.; Kondrashova, N.; Kononenko, O.; Korol, Ie.; Korzhavina, I. A.; Kotanski, A.; Kötz, U.; Kovalchuk, N.; Kowalski, H.; Kuprash, O.; Kuze, M.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Yu.; Maeda, J.; Makarenko, I.; Malka, J.; Martin, J. F.; Mergelmeyer, S.; Mohamad Idris, F.; Mujkic, K.; Myronenko, V.; Nagano, K.; Nigro, A.; Nobe, T.; Notz, D.; Nowak, R. J.; Olkiewicz, K.; Onishchuk, Yu.; Paul, E.; Perlanski, W.; Perrey, H.; Pokrovskiy, N. S.; Proskuryakov, A. S.; Przybycien, M.; Raval, A.; Roloff, P.; Rubinsky, I.; Ruspa, M.; Samojlov, V.; Saxon, D. H.; Schioppa, M.; Schmidke, W. B.; Schneekloth, U.; Schörner-Sadenius, T.; Schwartz, J.; Shcheglova, L. M.; Shehzadi, R.; Shevchenko, R.; Shkola, O.; Singh, I.; Skillicorn, I. O.; Slominski, W.; Sola, V.; Solano, A.; Spiridonov, A.; Stanco, L.; Stefaniuk, N.; Stern, A.; Stewart, T. P.; Stopa, P.; Sztuk-Dambietz, J.; Szuba, D.; Szuba, J.; Tassi, E.; Temiraliev, T.; Tokushuku, K.; Tomaszewska, J.; Trofymov, A.; Trusov, V.; Tsurugai, T.; Turcato, M.; Turkot, O.; Tymieniecka, T.; Verbytskyi, A.; Viazlo, O.; Walczak, R.; Wan Abdullah, W. A. T.; Wichmann, K.; Wing, M.; Wolf, G.; Yamada, S.; Yamazaki, Y.; Zakharchuk, N.; Żarnecki, A. F.; Zawiejski, L.; Zenaiev, O.; Zhautykov, B. O.; Zhmak, N.; Zotkin, D. S.

    2014-09-01

    The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q 2 < 1000 GeV2 using an integrated luminosity of 354 pb-1. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q 2, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q 2. The running beauty-quark mass, m b at the scale m b , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m b ( m b ) = 4.07 ± 0.14 (fit){-/0.07 + 0.01}(mod.){-/0.00 + 0.05}(param.){-/0.05 + 0.08}(theo.) GeV.

  20. Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

    NASA Astrophysics Data System (ADS)

    Abramowicz, H.; Abt, I.; Adamczyk, L.; Adamus, M.; Aggarwal, R.; Antonelli, S.; Arslan, O.; Aushev, V.; Aushev, Y.; Bachynska, O.; Barakbaev, A. N.; Bartosik, N.; Behnke, O.; Behr, J.; Behrens, U.; Bertolin, A.; Bhadra, S.; Bloch, I.; Bokhonov, V.; Boos, E. G.; Borras, K.; Brock, I.; Brugnera, R.; Bruni, A.; Brzozowska, B.; Bussey, P. J.; Caldwell, A.; Capua, M.; Catterall, C. D.; Chwastowski, J.; Ciborowski, J.; Ciesielski, R.; Cooper-Sarkar, A. M.; Corradi, M.; Corriveau, F.; D'Agostini, G.; Dementiev, R. K.; Devenish, R. C. E.; Dolinska, G.; Drugakov, V.; Dusini, S.; Ferrando, J.; Figiel, J.; Foster, B.; Gach, G.; Garfagnini, A.; Geiser, A.; Gizhko, A.; Gladilin, L. K.; Gogota, O.; Golubkov, Yu. A.; Grebenyuk, J.; Gregor, I.; Grzelak, G.; Gueta, O.; Guzik, M.; Hain, W.; Hartner, G.; Hochman, D.; Hori, R.; Ibrahim, Z. A.; Iga, Y.; Ishitsuka, M.; Iudin, A.; Januschek, F.; Kadenko, I.; Kananov, S.; Kanno, T.; Karshon, U.; Kaur, M.; Kaur, P.; Khein, L. A.; Kisielewska, D.; Klanner, R.; Klein, U.; Kondrashova, N.; Kononenko, O.; Korol, Ie.; Korzhavina, I. A.; Kotanski, A.; Kötz, U.; Kovalchuk, N.; Kowalski, H.; Kuprash, O.; Kuze, M.; Levchenko, B. B.; Levy, A.; Libov, V.; Limentani, S.; Lisovyi, M.; Lobodzinska, E.; Lohmann, W.; Löhr, B.; Lohrmann, E.; Longhin, A.; Lontkovskyi, D.; Lukina, O. Yu.; Maeda, J.; Makarenko, I.; Malka, J.; Martin, J. F.; Mergelmeyer, S.; Mohamad Idris, F.; Mujkic, K.; Myronenko, V.; Nagano, K.; Nigro, A.; Nobe, T.; Notz, D.; Nowak, R. J.; Olkiewicz, K.; Onishchuk, Yu.; Paul, E.; Perlanski, W.; Perrey, H.; Pokrovskiy, N. S.; Proskuryakov, A. S.; Przybycien, M.; Raval, A.; Roloff, P.; Rubinsky, I.; Ruspa, M.; Samojlov, V.; Saxon, D. H.; Schioppa, M.; Schmidke, W. B.; Schneekloth, U.; Schörner-Sadenius, T.; Schwartz, J.; Shcheglova, L. M.; Shehzadi, R.; Shevchenko, R.; Shkola, O.; Singh, I.; Skillicorn, I. O.; Slominski, W.; Sola, V.; Solano, A.; Spiridonov, A.; Stanco, L.; Stefaniuk, N.; Stern, A.; Stewart, T. P.; Stopa, P.; Sztuk-Dambietz, J.; Szuba, D.; Szuba, J.; Tassi, E.; Temiraliev, T.; Tokushuku, K.; Tomaszewska, J.; Trofymov, A.; Trusov, V.; Tsurugai, T.; Turcato, M.; Turkot, O.; Tymieniecka, T.; Verbytskyi, A.; Viazlo, O.; Walczak, R.; Wan Abdullah, W. A. T.; Wichmann, K.; Wing, M.; Wolf, G.; Yamada, S.; Yamazaki, Y.; Zakharchuk, N.; Żarnecki, A. F.; Zawiejski, L.; Zenaiev, O.; Zhautykov, B. O.; Zhmak, N.; Zotkin, D. S.

    2014-10-01

    The production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q 2 < 1000 GeV2 using an integrated luminosity of 354 pb-1. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q 2, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q 2. The running beauty-quark mass, m b at the scale m b , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m b ( m b ) = 4.07 ± 0.14 (fit){-/0.07 + 0.01}(mod.){-/0.00 + 0.05}(param.){-/0.05 + 0.08}(theo.) GeV.

  1. Effects of heavy sea quarks at low energies.

    PubMed

    Bruno, Mattia; Finkenrath, Jacob; Knechtli, Francesco; Leder, Björn; Sommer, Rainer

    2015-03-13

    We present a factorization formula for the dependence of light hadron masses and low energy hadronic scales on the mass M of a heavy quark: apart from an overall mass-independent factor Q, ratios such as r_{0}(M)/r_{0}(0) are computable in perturbation theory at large M. The perturbation theory part is stable concerning different loop orders. Our nonperturbative Monte Carlo results obtained in a model calculation, where a doublet of heavy quarks is decoupled, match quantitatively to the perturbative prediction. Upon taking ratios of different hadronic scales at the same mass, the perturbative function drops out and the ratios are given by the decoupled theory up to M^{-2} corrections. We verify-in the continuum limit-that the sea quark effects of quarks with masses around the charm mass are very small in such ratios. PMID:25815925

  2. Hybrid neutron stars with the Dyson-Schwinger quark model and various quark-gluon vertices

    NASA Astrophysics Data System (ADS)

    Chen, H.; Wei, J.-B.; Baldo, M.; Burgio, G. F.; Schulze, H.-J.

    2015-05-01

    We study cold dense quark matter and hybrid neutron stars with a Dyson-Schwinger quark model and various choices of the quark-gluon vertex. We obtain the equation of state of quark matter in beta equilibrium and investigate the hadron-quark phase transition in combination with a hadronic equation of state derived within the Brueckner-Hartree-Fock many-body theory. Comparing with the results for quark matter within the rainbow approximation, the Ball-Chiu (BC) Ansatz and the 1BC Ansatz for the quark-gluon vertex lead to a reduction of the effective interaction at finite chemical potential, qualitatively similar to the effect of our gluon propagator. We find that the phase transition and the equation of state of the quark or mixed phase and consequently the resulting hybrid star mass and radius depend mainly on a global reduction of the effective interaction due to effects of both the quark-gluon vertex and gluon propagator, but are not sensitive to details of the vertex Ansatz.

  3. Study of spin-dependent masses and configuration mixings in heavy quarkonia and hybrids using lattice nonrelativistic quantum chromodynamics

    NASA Astrophysics Data System (ADS)

    Burch, Tommy

    While we may know the overall quantum numbers of a given meson state and that such a state is necessarily a color singlet, we do not know a priori the relative spin and color alignments of the constituents: the quarks, antiquarks, and gluons. The overall meson wavefunction may have contributions from different spin-color configurations: one where the quark and antiquark alone account for the spin of the meson; or another where a gluon excitation also contributes to the total spin (a hybrid state), while helping to form the color singlet. The determination of the relative contributions of each these configurations to the overall meson state is the focus of this work. We use the lattice formulation of quantum chromodynamics (QCD) and we restrict our analysis to the limit of heavy quark masses. We are therefore able to use a non-relativistic approximation for the quark and antiquark Hamiltonians (NRQCD). This provides the additional separation of the spin- and orbital-angular-momentum degrees of freedom of the quarks. We therefore have a clear separation of basis states where the meson spin is carried by only the quark and antiquark spins, their relative orbital motion, or a combination of the two; and also the state where a gluon excitation is needed, along with the quark and antiquark, to form the correct quantum numbers. Using only the static and kinetic terms of the heavy-quark Hamiltonian we create meson-like correlators with the same quantum numbers, but with different color-spin configurations. From these correlators we extract the masses and amplitudes which form the basis of a two-state system. We then apply the lowest-order spin-dependent interaction at various intermediate time slices to form correlators between different configurations. From these "mixed" correlators we extract the off-diagonal matrix elements of our two-state Hamiltonian. Diagonalizing this Hamiltonian, we find the relative contribution of each spin-color configuration to the true heavy

  4. Mass dependency of turbulent parameters in stationary glow discharge plasmas

    SciTech Connect

    Titus, J. B.; Alexander, A. B.; Wiggins, D. L.; Johnson, J. A. III

    2013-05-15

    A direct current glow discharge tube is used to determine how mass changes the effects of certain turbulence characteristics in a weakly ionized gas. Helium, neon, argon, and krypton plasmas were created, and an axial magnetic field, varied from 0.0 to 550.0 Gauss, was used to enhance mass dependent properties of turbulence. From the power spectra of light emission variations associated with velocity fluctuations, determination of mass dependency on turbulent characteristic unstable modes, energy associated with turbulence, and the rate at which energy is transferred from scale to scale are measured. The magnetic field strength is found to be too weak to overcome particle diffusion to the walls to affect the turbulence in all four types of plasmas, though mass dependency is still detected. Though the total energy and the rate at which the energy moves between scales are mass invariant, the amplitude of the instability modes that characterize each plasma are dependent on mass.

  5. A measurement of the top quark's charge

    SciTech Connect

    Unalan, Zeynep Gunay; /Michigan State U.

    2007-11-01

    The top quark was discovered in 1995 at the Fermilab National Accelerator Laboratory (Fermilab). One way to confirm if the observed top quark is really the top quark posited in the Standard Model (SM) is to measure its electric charge. In the Standard Model the top quark is the isospin partner of the bottom quark and is expected to have a charge of +2/3. However, an alternative 'exotic' model has been proposed with a fourth generation exotic quark that has the same characteristics, such as mass, as our observed top but with a charge of -4/3. This thesis presents the first CDF measurement of the top quark's charge via its decay products, a W boson and a bottom quark, using {approx} 1 fb{sup -1} of data. The data were collected by the CDF detector from proton anti-proton (p{bar p}) collisions at {radical}s = 1.96 TeV at Fermilab. We classify events depending on the charges of the bottom quark and associated W boson and count the number of events which appear 'SM-like' or 'exotic-like' with a SM-like event decaying as t {yields} W{sup +}b and an exotic event as t {yields} W{sup -}b. We find the p-value under the Standard Model hypothesis to be 0:35 which is consistent with the Standard Model. We exclude the exotic quark hypothesis at an 81% confidence level, for which we have chosen a priori that the probability of incorrectly rejecting the SM would be 1%. The calculated Bayes Factor (BF) is 2 x Ln(BF)=8.54 which is interpreted as the data strongly favors the Standard Model over the exotic quark hypothesis.

  6. Can the four-zero-texture mass matrix model reproduce the observed quark and lepton mixing angles and CP-violating phases?

    SciTech Connect

    Matsuda, Koichi; Nishiura, Hiroyuki

    2006-08-01

    We reconsider a universal mass matrix model which has a seesaw-invariant structure with four-zero texture common to all quarks and leptons. The Cabibbo-Kobayashi-Maskawa (CKM) quark and Maki-Nakagawa-Sakata (MNS) lepton mixing matrices of the model are analyzed analytically. We show that the model can be consistent with all the experimental data of neutrino oscillation and quark mixings by tuning free parameters of the model. It is also shown that the model predicts a relatively large value for the (1, 3) element of the MNS lepton mixing matrix (U{sub MNS}){sub 13}{sup 2}{approx_equal}(0.041-9.6)x10{sup -2}. Using the seesaw mechanism, we also discuss the conditions for the components of the Dirac and the right-handed Majorana neutrino mass matrices which lead to the neutrino mass matrix consistent with the experimental data.

  7. OPE, charm-quark mass, and decay constants of D and Ds mesons from QCD sum rules

    PubMed Central

    Lucha, Wolfgang; Melikhov, Dmitri; Simula, Silvano

    2011-01-01

    We present a sum-rule extraction of the decay constants of the charmed mesons D and Ds from the two-point correlator of pseudoscalar currents. First, we compare the perturbative expansion for the correlator and the decay constant performed in terms of the pole and the running MS¯ masses of the charm quark. The perturbative expansion in terms of the pole mass shows no signs of convergence whereas reorganizing this very expansion in terms of the MS¯ mass leads to a distinct hierarchy of the perturbative expansion. Furthermore, the decay constants extracted from the pole-mass correlator turn out to be considerably smaller than those obtained by means of the MS¯-mass correlator. Second, making use of the OPE in terms of the MS¯ mass, we determine the decay constants of both D and Ds mesons with an emphasis on the uncertainties in these quantities related both to the input QCD parameters and to the limited accuracy of the method of sum rules. PMID:21949465

  8. Top quark physics: Future measurements

    SciTech Connect

    Frey, R.; Vejcik, S.; Berger, E.L.

    1997-04-04

    The authors discuss the study of the top quark at future experiments and machines. Top`s large mass makes it a unique probe of physics at the natural electroweak scale. They emphasize measurements of the top quark`s mass, width, and couplings, as well as searches for rare or nonstandard decays, and discuss the complementary roles played by hadron and lepton colliders.

  9. Nucleon transverse momentum-dependent parton distributions from domain wall fermion calculations at 297 MeV pion mass

    SciTech Connect

    Engelhardt, Michael; Musch, Bernhard; Bhattacharya, Tanmoy; Gupta, Rajan; Hagler, Phillip; Negele, John; Pochinsky, Andrew; Shafer, Andreas; Syritsyn, Sergey; Yoon, Boram

    2014-12-01

    Lattice QCD calculations of transverse momentum-dependent parton distributions (TMDs) in a nucleon are performed based on a definition of TMDs via hadronic matrix elements of quark bilocal operators containing staple-shaped gauge connections. A parametrization of the matrix elements in terms of invariant amplitudes serves to cast them in the Lorentz frame preferred for the lattice calculation. Using a RBC/UKQCD domain wall fermion ensemble corresponding to a pion mass of 297MeV, on a lattice with spacing 0.084fm, selected TMD observables are accessed and compared to previous explorations at heavier pion masses on coarser lattices.

  10. Nucleon transverse momentum-dependent parton distributions from domain wall fermion calculations at 297 MeV pion mass

    SciTech Connect

    Engelhardt, M.; Musch, B.; Bhattacharya, T.; Gupta, R.; Hagler, P.; Negele, J.; Pochinsky, A.; Schafer, A.; Syritsyn, S.; Yoon, B.

    2014-06-23

    Here, lattice QCD calculations of transverse momentum-dependent parton distributions (TMDs) in a nucleon are performed based on a definition of TMDs via hadronic matrix elements of quark bilocal operators containing staple-shaped gauge connections. A parametrization of the matrix elements in terms of invariant amplitudes serves to cast them in the Lorentz frame preferred for the lattice calculation. Using a RBC/UKQCD domain wall fermion ensemble corresponding to a pion mass of 297 MeV, on a lattice with spacing 0.084 fm, selected TMD observables are accessed and compared to previous exploration at heavier pion masses on coarser lattices.

  11. QUARK MATTER IN MASSIVE COMPACT STARS

    SciTech Connect

    Weissenborn, Simon; Pagliara, Giuseppe; Schaffner-Bielich, Juergen; Sagert, Irina; Hempel, Matthias

    2011-10-10

    The recent observation of the pulsar PSR J1614-2230 with a mass of 1.97 {+-} 0.04 M{sub sun} gives a strong constraint on the quark and nuclear matter equations of state (EoS). We explore the parameter ranges for a parameterized EoS for quark stars. We find that strange stars, made of absolutely stable strange quark matter, comply with the new constraint only if effects from the strong coupling constant and color-superconductivity are taken into account. Hybrid stars, compact stars with a quark matter core and a hadronic outer layer, can be as massive as 2 M{sub sun}, but only for a significantly limited range of parameters. We demonstrate that the appearance of quark matter in massive stars crucially depends on the stiffness of the nuclear matter EoS. We show that the masses of hybrid stars stay below the ones of hadronic and pure quark stars, due to the softening of the EoS at the quark-hadron phase transition.

  12. Quark matter and meson properties in a Nonlocal SU(3) chiral quark model at finite temperature

    SciTech Connect

    Gomez Dumm, D.; Contrera, G. A.

    2012-06-15

    We study the finite temperature behavior of light scalar and pseudoscalar meson properties in the context of a three-flavor nonlocal chiral quark model. The model includes mixing with active strangeness degrees of freedom, and takes care of the effect of gauge interactions by coupling the quarks with a background color field. We analyze the chiral restoration and deconfinement transitions, as well as the temperature dependence of meson masses, mixing angles, and decay constants.

  13. Composite quarks and leptons

    SciTech Connect

    Preskill, J.

    1982-01-01

    Calculability of quark and lepton masses and mixing angles is stressed as the primary motivation for constructing models in which quarks and leptons are composite particles. A general strategy for constructing such models is outlined, in which quarks and leptons are kept light compared to their inverse sizes by approximate chiral symmetries. The origin of multiple families is discussed, and an unrealistic model is exhibited which has several generations and a complicated pattern of masses and generation-mixing angles. The new physics responsible for binding quarks and leptons tends to induce various rare processes at rates which are potentially too large.

  14. Measurement of the top quark mass with the matrix element method in the semileptonic decay channel at D0

    SciTech Connect

    Haefner, Petra

    2008-07-31

    The top quark plays a special role in the Standard Model of Particle Physics. With its enormous mass of about 170 GeV it is as heavy as a gold atom and is the only quark with a mass near the electroweak scale. Together with theW boson mass, the top quark mass allows indirect constraints on the mass of the hypothetical Higgs boson, which might hold the clue to the origin of mass. Top pair production with a semileptonic decay t $\\bar{t}$ →W±W b$\\bar{b}$ →q $\\bar{t}$lnb$\\bar{b}$ is the ”golden channel” for mass measurements, due to a large branching fraction and a relatively low background contamination compared to other decay channels. Top mass measurements based on this decay, performed with the matrix element method, have always been among the single best measurements in the world. In 2007, the top mass world average broke the 1% level of precision. Its measurement is no longer dominated by statistical but instead by systematic uncertainties. The reduction of systematic uncertainties has therefore become a key issue for further progress. This thesis introduces two new developments in the treatment of b jets. The first improvement is an optimization in the way b identification information is used. It leads to an enhanced separation between signal and background processes and reduces the statistical uncertainty by about 16%. The second improvement determines differences in the detector response and thus the energy scales of light jets and b jets. Thereby, it addresses the major source of systematic uncertainty in the latest top mass measurements. The method was validated on Monte Carlo events at the generator level, calibrated with fully simulated events, including detector simulation, and applied to D0 Run II data corresponding to 1 fb-1 of integrated luminosity. Possible sources of systematic uncertainties were studied. The top mass is measured to be: mt = (169.2±3.5(stat.)±1.0(syst.)) GeV . The

  15. Combination of CDF and D0 results on the mass of the top quark using up to 5.8~fb-1 of data

    SciTech Connect

    Lancaster, Mark; /Fermilab

    2011-07-01

    We summarize the top-quark mass measurements from the CDF and D0 experiments at Fermilab. We combine published Run I (1992--1996) measurements with the most precise published and preliminary Run II (2001--present) measurements using up to 5.8 fb{sup -1} of data, adding new analyses (the missing transverse energy plus jets analysis) and updating old ones. Taking uncertainty correlations into account, and adding in quadrature the statistical and systematic uncertainties, the resulting preliminary Tevatron average mass of the top quark is M{sub t} = 173.2 {+-} 0.9 GeV/c{sup 2}.

  16. Combination of CDF and D0 results on the mass of the top quark using up to 9.7 fb$^{-1}$ at the Tevatron

    SciTech Connect

    Tevatron Electroweak Working Group, Tevatron Group

    2014-07-10

    We summarize the current top-quark mass measurements from the CDF and D0 experiments at Fermilab. We combine published Run I (1992--1996) results with the most precise published and preliminary Run II (2001--2011) measurements based on data corresponding to up to 9.7 fb$^{-1}$ of $p\\bar{p}$ collisions. Taking correlations of uncertainties into account, and combining the statistical and systematic uncertainties, the resulting preliminary Tevatron average mass of the top quark is $M_{top} = 174.34 \\pm 0.64 ~GeV/c^2$, corresponding to a relative precision of 0.37%.

  17. The anomalous gamma -> pi{sup +} pi{sup 0} pi{sup -} form factor and the light-quark mass functions at low momenta

    SciTech Connect

    Dubravko Klabucar; Bojan Bistrovic

    2000-12-01

    The gamma -> 3 pi form factor was calculated in a simple-minded constituent model with a constant quark mass parameter, as well as in the Schwinger-Dyson approach. The comparison of these and various other theoretical results on this anomalous process, as well as the scarce already available data (hopefully to be supplemented by more accurate CEBAF data), seem to favor Schwinger-Dyson modeling which would yield relatively small low-momentum values of the constituent (dynamically dressed) quark mass function.

  18. Inclusive photoproduction of bottom quarks for low and medium pT in the general-mass variable-flavour-number scheme

    NASA Astrophysics Data System (ADS)

    Kramer, G.; Spiesberger, H.

    2016-02-01

    We present predictions for b-quark production in photoproduction and compare with experimental data from HERA. Our theoretical predictions are obtained at next-to-leading-order in the general-mass variable-flavor-number scheme, an approach which takes into account the finite mass of the b quarks. We use realistic evolved nonperturbative fragmentation functions obtained from fits to e+e- data. We find in general good agreement of data with both the GM-VFNS and the FFNS calculations, while the more precise ZEUS data seem to prefer the GM-VFNS predictions.

  19. Measurements and searches with top quarks

    SciTech Connect

    Peters, Reinhild Yvonne; /Wuppertal U.

    2008-10-01

    to search for charged or neutral Higgs bosons. Depending on its mass, the charged Higgs boson is expected to decay either into top quarks or be the decay product of a top quark. For masses below the top quark mass, the top decay into a charged Higgs boson and a b quark can occur at a certain rate, additionally to the decays into W bosons and a b quark. The different decays of W and charged Higgs bosons can lead to deviations of the observed final number of events in certain final states with respect to the Standard Model expectation. A global search for charged Higgs bosons in top quark pair events is presented in this thesis, resulting in the most stringent limits to-date. Besides the decay of top quarks into charged Higgs or W bosons, new physics can also show up in the quark part of the decay. While in the Standard Model the top quark decays with a rate of about 100% into a W boson and a b quark, there are models where the top quark can decay into a W boson and a non-b quark. The ratio of branching fractions in which the top quark decays into a b quark over the branching fractions in which the top quark decays into all quarks is measured as part of this thesis, yielding the most precise measurement today. Furthermore, the Standard Model top quark pair production cross section is essential to be known precisely since the top quark pair production is the main background for t{bar t}H production and many other Higgs and beyond the Standard Model searches. However, not only the search or the test of the Standard Model itself make the precise measurement of the top quark pair production cross section interesting. As the cross section is calculated with high accuracy in perturbative QCD, a comparison of the measurement to the theory expectation yields the possibility to extract the top quark mass from the cross section measurement. Although many dedicated techniques exist to measure the top quark mass, the extraction from the cross section represents an important

  20. Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector

    DOE PAGESBeta

    Aaltonen, T.

    2011-10-14

    A measurement of the top-quark mass is presented using Tevatron data from proton-antiproton collisions at center-of-mass energy √s = 1.96 TeV collected with the CDF II detector. Events are selected from a sample of candidates for production of tt̄ pairs that decay into the lepton+jets channel. The top-quark mass is measured with an unbinned maximum likelihood method where the event probability density functions are calculated using signal and background matrix elements, as well as a set of parameterized jet-to-parton transfer functions. The likelihood function is maximized with respect to the top-quark mass, the signal fraction in the sample, and amore » correction to the jet energy scale (JES) calibration of the calorimeter jets. The simultaneous measurement of the JES correction ({Delta}{sub JES}) amounts to an additional in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using the data sample of 578 lepton+jets candidate events, corresponding to 3.2 fb-1 of integrated luminosity, the top-quark mass is measured to be mt = 172.4± 1.4 (stat + ΔJES) ± 1.3 (syst) GeV/c2.« less

  1. Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector

    SciTech Connect

    Aaltonen, T.

    2011-10-14

    A measurement of the top-quark mass is presented using Tevatron data from proton-antiproton collisions at center-of-mass energy √s = 1.96 TeV collected with the CDF II detector. Events are selected from a sample of candidates for production of tt̄ pairs that decay into the lepton+jets channel. The top-quark mass is measured with an unbinned maximum likelihood method where the event probability density functions are calculated using signal and background matrix elements, as well as a set of parameterized jet-to-parton transfer functions. The likelihood function is maximized with respect to the top-quark mass, the signal fraction in the sample, and a correction to the jet energy scale (JES) calibration of the calorimeter jets. The simultaneous measurement of the JES correction ({Delta}{sub JES}) amounts to an additional in situ jet energy calibration based on the known mass of the hadronically decaying W boson. Using the data sample of 578 lepton+jets candidate events, corresponding to 3.2 fb-1 of integrated luminosity, the top-quark mass is measured to be mt = 172.4± 1.4 (stat + ΔJES) ± 1.3 (syst) GeV/c2.

  2. Top quark physics

    SciTech Connect

    Ahmadov, A.; Azuelos, G.; Bauer, U.; Belyaev, A.; Berger, E. L.; Sullivan, Z.; Tait, T. M. P.

    2000-03-24

    The top quark, when it was finally discovered at Fermilab in 1995 completed the three-generation structure of the Standard Model (SM) and opened up the new field of top quark physics. Viewed as just another SM quark, the top quark appears to be a rather uninteresting species. Produced predominantly, in hadron-hadron collisions, through strong interactions, it decays rapidly without forming hadrons, and almost exclusively through the single mode t {r_arrow} Wb. The relevant CKM coupling V{sub tb} is already determined by the (three-generation) unitarity of the CKM matrix. Rare decays and CP violation are unmeasurable small in the SM. Yet the top quark is distinguished by its large mass, about 35 times larger than the mass of the next heavy quark, and intriguingly close to the scale of electroweak (EW) symmetry breaking. This unique property raises a number of interesting questions. Is the top quark mass generated by the Higgs mechanism as the SM predicts and is its mass related to the top-Higgs-Yukawa coupling? Or does it play an even more fundamental role in the EW symmetry breaking mechanism? If there are new particles lighter than the top quark, does the top quark decay into them? Could non-SM physics first manifest itself in non-standard couplings of the top quark which show up as anomalies in top quark production and decays? Top quark physics tries to answer these questions. Several properties of the top quark have already been examined at the Tevatron. These include studies of the kinematical properties of top production, the measurements of the top mass, of the top production cross-section, the reconstruction of t{bar t}pairs in the fully hadronic final states, the study of {tau} decays of the top quark, the reconstruction of hadronic decays of the W boson from top decays, the search for flavor changing neutral current decays, the measurement of the W helicity in top decays, and bounds on t{bar t} spin correlations. Most of these measurements are limited by

  3. Effects of strong interaction on the structure of color-flavor-locked quark stars

    SciTech Connect

    Oliveira, J. C. T.; Rodrigues, H.; Duarte, S. B.

    2008-12-15

    The static spherically symmetric quark star structure is calculated by using an equation of state which takes into account the superconducting color-flavor locked phase of the strange quark matter. Some fundamental aspects of QCD (asymptotic freedom and confinement) are considered by means of a phenomenological description of the deconfined quark phase, namely, the density-dependent quark mass model. The effects from the strong interaction described by these models can affect the equation of state of the quark matter substantially. In this work we discuss the influence of these effects on the conventional mass-radius relationship of quark stars. Massive quark stars are found due to the stiffness of the equation of state at low densities, when reasonable values of the superconducting gap, taken as a free parameter, are used.

  4. Measurement of the Top Quark Mass by Dynamical Likelihood Method using the Lepton + Jets Events with the Collider Detector at Fermilab

    SciTech Connect

    Kubo, Taichi

    2008-02-01

    We have measured the top quark mass with the dynamical likelihood method. The data corresponding to an integrated luminosity of 1.7fb-1 was collected in proton antiproton collisions at a center of mass energy of 1.96 TeV with the CDF detector at Fermilab Tevatron during the period March 2002-March 2007. We select t$\\bar{t}$ pair production candidates by requiring one high energy lepton and four jets, in which at least one of jets must be tagged as a b-jet. In order to reconstruct the top quark mass, we use the dynamical likelihood method based on maximum likelihood method where a likelihood is defined as the differential cross section multiplied by the transfer function from observed quantities to parton quantities, as a function of the top quark mass and the jet energy scale(JES). With this method, we measure the top quark mass to be 171.6 ± 2.0 (stat.+ JES) ± 1.3(syst.) = 171.6 ± 2.4 GeV/c2.

  5. Measurement of the Top Quark Mass and ppbar -> ttbar Cross Section in the All-Hadronic Mode with the CDFII Detector

    SciTech Connect

    Aaltonen, T.; Adelman, J.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.; Apresyan, A.; /Purdue U. /Waseda U.

    2010-02-01

    We present a measurement of the top quark mass and of the top-antitop pair production cross section using p{bar p} data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator Laboratory and corresponding to an integrated luminosity of 2.9 fb{sup -1}. We select events with six or more jets satisfying a number of kinematical requirements imposed by means of a neural network algorithm. At least one of these jets must originate from a b quark, as identified by the reconstruction of a secondary vertex inside the jet. The mass measurement is based on a likelihood fit incorporating reconstructed mass distributions representative of signal and background, where the absolute jet energy scale (JES) is measured simultaneously with the top quark mass. The measurement yields a value of 174.8 {+-} 2.4(stat+JES){sub -1.0}{sup +1.2}(syst)GeV/c{sup 2}, where the uncertainty from the absolute jet energy scale is evaluated together with the statistical uncertainty. The procedure measures also the amount of signal from which we derive a cross section, {sigma}{sub t{bar t}} = 7.2 {+-} 0.5(stat) {+-} 1.0(syst) {+-} 0.4(lum) pb, for the measured values of top quark mass and JES.

  6. QCD equation of state at nonzero chemical potential: continuum results with physical quark masses at order μ 2

    NASA Astrophysics Data System (ADS)

    Borsányi, Sz.; Endrődi, G.; Fodor, Z.; Katz, S. D.; Krieg, S.; Ratti, C.; Szabó, K. K.

    2012-08-01

    We determine the equation of state of QCD for nonzero chemical potentials via a Taylor expansion of the pressure. The results are obtained for N f = 2 + 1 flavors of quarks with physical masses, on various lattice spacings. We present results for the pressure, interaction measure, energy density, entropy density, and the speed of sound for small chemical potentials. At low temperatures we compare our results with the Hadron Resonance Gas model. We also express our observables along trajectories of constant entropy over particle number. A simple parameterization is given (the Matlab/Octave script parameterization.m, submitted to the arXiv along with the paper), which can be used to reconstruct the observables as functions of T and μ, or as functions of T and S/N.

  7. Shear and bulk viscosities of quark matter from quark-meson fluctuations in the Nambu-Jona-Lasinio model

    NASA Astrophysics Data System (ADS)

    Ghosh, Sabyasachi; Peixoto, Thiago C.; Roy, Victor; Serna, Fernando E.; Krein, Gastão

    2016-04-01

    We have calculated the temperature dependence of shear η and bulk ζ viscosities of quark matter due to quark-meson fluctuations. The quark thermal width originating from quantum fluctuations of quark-π and quark-σ loops at finite temperature is calculated with the formalism of real-time thermal field theory. Temperature-dependent constituent-quark and meson masses and quark-meson couplings are obtained in the Nambu-Jona-Lasinio model. We found a nontrivial influence of the temperature-dependent masses and couplings on the Landau-cut structure of the quark self-energy. Our results for the ratios η /s and ζ /s , where s is the entropy density (also determined in the Nambu-Jona-Lasinio model in the quasiparticle approximation), are in fair agreement with results of the literature obtained from different models and techniques. In particular, our result for η /s has a minimum very close to the quantum lower bound, η /s =1 /4 π .

  8. Measurement of the top quark mass using proton-proton data at √{(}s )=7 and 8 TeV

    NASA Astrophysics Data System (ADS)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Van Parijs, I.; Barria, P.; Brun, H.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Fasanella, G.; Favart, L.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Perniè, L.; Randle-conde, A.; Reis, T.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Beernaert, K.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Sigamani, M.; Strobbe, N.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Mertens, A.; Musich, M.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Beliy, N.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hamer, M.; Hensel, C.; Mora Herrera, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; De Souza Santos, A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; El-khateeb, E.; Elkafrawy, T.; Mohamed, A.; Mohammed, Y.; Salama, E.; Calpas, B.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Dahms, T.; Davignon, O.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Lisniak, S.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.

    2016-04-01

    A new set of measurements of the top quark mass are presented, based on the proton-proton data recorded by the CMS experiment at the LHC at √{s }=8 TeV corresponding to a luminosity of 19.7 fb-1 . The top quark mass is measured using the lepton+jets , all-jets and dilepton decay channels, giving values of 172.35 ±0.16 (stat )±0.48 (syst ) GeV , 172.32 ±0.25 (stat )±0.59 (syst ) GeV , and 172.82 ±0.19 (stat )±1.22 (syst ) GeV , respectively. When combined with the published CMS results at √{s }=7 TeV , they provide a top quark mass measurement of 172.44 ±0.13 (stat )±0.47 (syst ) GeV . The top quark mass is also studied as a function of the event kinematical properties in the lepton+jets decay channel. No indications of a kinematic bias are observed and the collision data are consistent with a range of predictions from current theoretical models of t t ¯ production.

  9. A Measurement of the mass of the Top Quark in the di-lepton channels using the D0 Detector at Fermilab

    SciTech Connect

    Fatakia, Sarosh Noshir

    2005-01-01

    This dissertation describes a measurement of the mass of the top quark using events consistent with the hypothesis t{bar t} {yields} bW{sup +} {bar b}W{sup -} {yields} bl{sup +}{nu}{bar b}l{sup -}{bar {nu}}, where (l=e,{mu}). The events are obtained from nearly 230 pb{sup -1} of p{bar p} collision data collected by the D0 experiment between 2002 and 2004 during Run II. In this decay channel two neutrinos remain undetected. Extraction of the mass of the top quark by kinematic reconstruction is not possible because the event is under-constrained. Therefore, a dynamical likelihood method is developed to obtain the mass of the top quark. The mass of top quark obtained from the candidate events selected in the di-electron channel and the e{mu} channel is: 154.1 {sup +14.2}{sub -12.8}(stat.) {+-}6.6 (syst.) GeV.

  10. Weak quark couplings induced by gluon corrections

    NASA Astrophysics Data System (ADS)

    Gavela, M. B.; Le Yaouanc, A.; Oliver, L.; Pène, O.; Raynal, J. C.

    1980-12-01

    We compute the quark couplings in flavor-changing semileptonic transitions induced by lowest-order gluon corrections. We investigate the consequences of these radiative corrections for the quark axial-vector coupling, the deviations from Cabibbo universality for the axial-vector relative to the vector current, and the induced couplings (first-class pseudoscalar and anomalous magnetic moment, and second-class scalar and pseudotensor). The correction lowers the axial-vector coupling and increases the magnetic moment. We study the dependence of the couplings on the quark mass difference. Some of these results, true to all orders in αs, generalize the theorem of Ademollo and Gatto. The effective current is pure V-A to a very good approximation for transitions of heavy quarks (m>~5 GeV).

  11. Measurement of the top-quark mass in all-jets $$t\\bar{t}$$ events in pp collisions at $$\\sqrt{s}$$=7 TeV

    DOE PAGESBeta

    Chatrchyan, Serguei

    2013-07-17

    The mass of the top quark is measured using a sample ofmore » $$t\\bar{t}$$ candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at $$\\sqrt{s}$$ = 7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 inverse femtobarns. The mass is reconstructed for each event employing a kinematic fit of the jets to a $$t\\bar{t}$$ hypothesis. The top-quark mass is measured to be 173.49 $$\\pm$$ 0.69 (stat.) $$\\pm$$ 1.21 (syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54 $$\\pm$$ 0.33 (stat.) $$\\pm$$ 0.96 (syst.) GeV.« less

  12. Measurement of the top-quark mass in all-jets $t\\bar{t}$ events in pp collisions at $\\sqrt{s}$=7 TeV

    SciTech Connect

    Chatrchyan, Serguei

    2013-07-17

    The mass of the top quark is measured using a sample of $t\\bar{t}$ candidate events with at least six jets in the final state. The sample is selected from data collected with the CMS detector in pp collisions at $\\sqrt{s}$ = 7 TeV in 2011 and corresponds to an integrated luminosity of 3.54 inverse femtobarns. The mass is reconstructed for each event employing a kinematic fit of the jets to a $t\\bar{t}$ hypothesis. The top-quark mass is measured to be 173.49 $\\pm$ 0.69 (stat.) $\\pm$ 1.21 (syst.) GeV. A combination with previously published measurements in other decay modes by CMS yields a mass of 173.54 $\\pm$ 0.33 (stat.) $\\pm$ 0.96 (syst.) GeV.

  13. Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)

    SciTech Connect

    Meyer, Joerg; /Bonn U.

    2007-01-01

    Elementary particle physics raises questions that are several thousand years old. What are the fundamental components of matter and how do they interact? These questions are linked to the question of what happened in the very first moments after the creation of the universe. Modern physics systematically tests nature to find answers to these and other fundamental questions. Precise theories are developed that describe various phenomena and at the same time are reduced to a few basic principals of nature. Simplification and reduction have always been guiding concepts of physics. The interplay between experimental data and theoretical descriptions led to the Standard Model of elementary particle physics. It summarizes the laws of nature and is one of most precise descriptions of nature achieved by mankind. Despite the great success of the Standard Model it is not the ultimate theory of everything. Models beyond the Standard Model try to unify all interactions in one grand unified theory. The number of free parameters is attempted to be reduced. Gravity is attempted to be incorporated. Extensions to the Standard Model like supersymmetry address the so-called hierarchy problem. Precision measurements are the key for searches of new particles and new physics. A powerful tool of experimental particle physics are particle accelerators. They provide tests of the Standard Model at smallest scales. New particles are produced and their properties are investigated. In 1995 the heaviest known elementary particle, called top quark, has been discovered at Fermilab. It differs from all other lighter quarks due to the high mass and very short lifetime. This makes the top quark special and an interesting object to be studied. A rich program of top physics at Fermilab investigates whether the top quark is really the particle as described by the Standard Model. The top quark mass is a free parameter of the theory that has been measured precisely. This thesis presents a precise

  14. Tests of constituent-quark generation methods which maintain both the nucleon center of mass and the desired radial distribution in Monte Carlo Glauber models

    NASA Astrophysics Data System (ADS)

    Mitchell, J. T.; Perepelitsa, D. V.; Tannenbaum, M. J.; Stankus, P. W.

    2016-05-01

    Several methods of generating three constituent quarks in a nucleon are evaluated which explicitly maintain the nucleon's center of mass and desired radial distribution and can be used within Monte Carlo Glauber frameworks. The geometric models provided by each method are used to generate distributions over the number of constituent quark participants (Nqp) in p +p ,d +Au , and Au +Au collisions. The results are compared with each other and to a previous result of Nqp calculations, without this explicit constraint, used in measurements of √{sNN}=200 GeV p +p ,d +Au , and Au +Au collisions at the BNL Relativistic Heavy Ion Collider.

  15. Mass-dependent and non-mass-dependent isotope effects in ozone photolysis: Resolving theory and experiments

    SciTech Connect

    Cole, Amanda S.; Boering, Kristie A.

    2006-11-14

    In addition to the anomalous {sup 17}O and {sup 18}O isotope effects in the three-body ozone formation reaction O+O{sub 2}+M, isotope effects in the destruction of ozone by photolysis may also play a role in determining the isotopic composition of ozone and other trace gases in the atmosphere. While previous experiments on ozone photolysis at 254 nm were interpreted as evidence for preferential loss of light ozone that is anomalous (or 'non-mass-dependent'), recent semiempirical theoretical calculations predicted a preferential loss of heavy ozone at that wavelength that is mass dependent. Through photochemical modeling results presented here, we resolve this apparent contradiction between experiment and theory. Specifically, we show that the formation of ozone during the UV photolysis experiments is not negligible, as had been assumed, and that the well-known non-mass-dependent isotope effects in ozone formation can account for the non-mass-dependent enrichment of the heavy isotopologs of ozone observed in the experiment. Thus, no unusual non-mass-dependent fractionation in ozone photolysis must be invoked to explain the experimental results. Furthermore, we show that theoretical predictions of a mass-dependent preferential loss of the heavy isotopologs of ozone during UV photolysis are not inconsistent with the experimental data, particularly if mass-dependent isotope effects in the chemical loss reactions of ozone during the photolysis experiments or experimental artifacts enrich the remaining ozone in {sup 17}O and {sup 18}O. Before the calculated fractionation factors can be quantitatively evaluated, however, further investigation of possible mass-dependent isotope effects in the reactions of ozone with O({sup 1}D), O({sup 3}P), O{sub 2}({sup 1}{delta}), and O{sub 2}({sup 1}{sigma}) is needed through experiments we suggest here.

  16. Quark Contributions to Nucleon Momentum and Spin from Domain Wall fermion calculations

    SciTech Connect

    Syritsyn, Sergey N.; Green, Jeremy R.; Negele, John W.; Pochinsky, Andrew; Hagler, Philipp G.; Musch, Bernhard U.; Schroers, Wolfram

    2011-12-01

    We report contributions to the nucleon spin and momentum from light quarks calculated using dynamical domain wall fermions with pion masses down to 300 MeV and fine lattice spacing a=0.084 fm. Albeit without disconnected diagrams, we observe that spin and orbital angular momenta of both u and d quarks are opposite, almost canceling in the case of the d quark, which agrees with previous calculations using a mixed quark action. We also present the full momentum dependence of n=2 generalized form factors showing little variation with the pion mass.

  17. Fermion Mass Renormalization Using Time-dependent Relativistic Quantum Mechanics

    NASA Astrophysics Data System (ADS)

    Kutnink, Timothy; Santrach, Amelia; Hocket, Sarah; Barcus, Scott; Petridis, Athanasios

    2015-10-01

    The time-dependent electromagnetically self-coupled Dirac equation is solved numerically by means of the staggered-leap-frog algorithm with refcecting boundary conditions. The stability region of the method versus the interaction strength and the spatial-grid size over time-step ratio is established. The expectation values of several dynamic operators are then evaluated as functions of time. These include the fermion and electromagnetic energies and the fermion dynamic mass, as the self-interacting spinors are no longer mass-eigenfunctions. There is a characteristic, non-exponential, oscillatory dependence leading to asymptotic constants of these expectation values. In the case of the fermion mass this amounts to renormalization. The dependence of the expectation values on the spatial-grid size is evaluated in detail. Statistical regularization is proposed to remove the grid-size dependence.

  18. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons

    SciTech Connect

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  19. Cold quark matter

    SciTech Connect

    Kurkela, Aleksi; Romatschke, Paul; Vuorinen, Aleksi

    2010-05-15

    We perform an O({alpha}{sub s}{sup 2}) perturbative calculation of the equation of state of cold but dense QCD matter with two massless and one massive quark flavor, finding that perturbation theory converges reasonably well for quark chemical potentials above 1 GeV. Using a running coupling constant and strange quark mass, and allowing for further nonperturbative effects, our results point to a narrow range where absolutely stable strange quark matter may exist. Absent stable strange quark matter, our findings suggest that quark matter in (slowly rotating) compact star cores becomes confined to hadrons only slightly above the density of atomic nuclei. Finally, we show that equations of state including quark matter lead to hybrid star masses up to M{approx}2M{sub {center_dot},} in agreement with current observations. For strange stars, we find maximal masses of M{approx}2.75M{sub {center_dot}}and conclude that confirmed observations of compact stars with M>2M{sub {center_dot}}would strongly favor the existence of stable strange quark matter.

  20. Quark eigenmodes and lattice QCD

    NASA Astrophysics Data System (ADS)

    Liu, Guofeng

    In this thesis, we study a number of topics in lattice QCD through the low-lying quark eigenmodes in the domain wall fermion (DWF) formulation in the quenched approximation. Specifically, we present results for the chiral condensate measured from these eigenmodes; we investigate the QCD vacuum structure by looking at the correlation between the magnitude of the chirality density, |psi†(x)gamma5psi( x)|, and the normal density, psi†( x)psi(x), for these states; we study the behavior of DWF formulation at large quark masses by investigating the mass dependence of the eigenvalues of the physical four dimensional-states as well as the bulk, five-dimensional states.

  1. Experimental investigation of mass-dependent and mass-independent fractionation of mercury isotopes

    NASA Astrophysics Data System (ADS)

    Bergquist, B. A.; Blum, J. D.; Marcus, J. W.; Biswas, A.

    2006-12-01

    Mercury is a globally distributed and highly toxic pollutant, the mobility and bioaccumulation of which is highly dependent on its redox cycling. With seven isotopes (including two odd-mass isotopes) and a relative mass difference of 4%, stable isotope fractionation of Hg could be a powerful tool to track and understand Hg cycling in the environment. Ongoing studies of natural mercury isotope variations in ore deposits, hydrothermal fluids, sediments, soils, fish tissues and bacterial cultures have documented a measurable range in Hg isotopes of up to ~5‰ in the ^{202}Hg/^{198}Hg ratio with most samples displaying mass-dependent fractionation. A small, but growing, body of data also suggests that natural samples display mass-independent fractionation of Hg isotopes. In this study, we explore mechanisms that lead to both mass- dependent and mass-independent fractionation of Hg isotopes. Isotope ratios were measured by continuous- flow cold-vapor generation coupled to MC-ICPMS with an external precision of ±0.1‰ (2SD). We observe three distinct types of isotope fractionation for Hg: (1) mass-dependent fractionation, (2) mass- independent fractionation of odd isotopes concurrent with mass-dependent fractionation of even isotopes, and (3) mass-independent fractionation of all Hg isotopes. Reduction of Hg species to Hg(0) vapor is an important mechanism for removal of Hg from aqueous systems into the atmosphere. Reduction of Hg occurs through numerous pathways including photoreduction, abiotic organic reduction, and biological reduction. We find that photoreduction of Hg(II) by natural sunlight leads to mass-independent fractionation of the odd isotopes (^{201}Hg, ^{199}Hg) with several permil deviations from predicted mass dependence, and mass- dependent fractionation of the even isotopes. In contrast, both biological reduction (Kritee et al., 2006) and dark abiotic organically mediated reduction follow mass-dependent fractionation of even and odd isotopes

  2. Renormalization scheme dependence of the two-loop QCD corrections to the neutral Higgs-boson masses in the MSSM

    NASA Astrophysics Data System (ADS)

    Borowka, S.; Hahn, T.; Heinemeyer, S.; Heinrich, G.; Hollik, W.

    2015-09-01

    Reaching a theoretical accuracy in the prediction of the lightest MSSM Higgs-boson mass, , at the level of the current experimental precision requires the inclusion of momentum-dependent contributions at the two-loop level. Recently two groups presented the two-loop QCD momentum-dependent corrections to (Borowka et al., Eur Phys J C 74(8):2994, 2014; Degrassi et al., Eur Phys J C 75(2):61, 2015), using a hybrid on-shell- scheme, with apparently different results. We show that the differences can be traced back to a different renormalization of the top-quark mass, and that the claim in Ref. Degrassi et al. (Eur Phys J C 75(2):61, 2015) of an inconsistency in Ref. Borowka et al. (Eur Phys J C 74(8):2994, 2014) is incorrect. We furthermore compare consistently the results for obtained with the top-quark mass renormalized on-shell and . The latter calculation has been added to the FeynHiggs package and can be used to estimate missing higher-order corrections beyond the two-loop level.

  3. Measurement of the top-quark mass in the t t xAF dilepton channel using the full CDF Run II data set

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2015-08-01

    We present a measurement of the top-quark mass in events containing two leptons (electrons or muons) with a large transverse momentum, two or more energetic jets, and a transverse-momentum imbalance. We use the full proton-antiproton collision data set collected by the CDF experiment during the Fermilab Tevatron Run II at center-of-mass energy √{s }=1.96 TeV , corresponding to an integrated luminosity of 9.1 fb-1 . A special observable is exploited for an optimal reduction of the dominant systematic uncertainty, associated with the knowledge of the absolute energy of the hadronic jets. The distribution of this observable in the selected events is compared to simulated distributions of t t ¯ dilepton signal and background. We measure a value for the top-quark mass of 171.5 ±1.9 (stat)±2.5 (syst) GeV /c2 .

  4. Isotopic mass-dependence of noble gas diffusion coefficients inwater

    SciTech Connect

    Bourg, I.C.; Sposito, G.

    2007-06-25

    Noble gas isotopes are used extensively as tracers inhydrologic and paleoclimatic studies. These applications requireknowledge of the isotopic mass (m) dependence of noble gas diffusioncoefficients in water (D), which has not been measured but is estimatedusing experimental D-values for the major isotopes along with an untestedrelationship from kinetic theory, D prop m-0.5. We applied moleculardynamics methods to determine the mass dependence of D for four noblegases at 298 K, finding that D prop m-beta with beta<0.2, whichrefutes the kinetic theory model underlying all currentapplications.

  5. Delta and Omega masses in a three-quark covariant Faddeev approach

    NASA Astrophysics Data System (ADS)

    Sanchis-Alepuz, Helios; Eichmann, Gernot; Villalba-Chávez, Selym; Alkofer, Reinhard

    2011-11-01

    We present the solution of the Poincaré-covariant Faddeev equation for the Δ(1232) and Ω(1672) baryons. The covariant structure of the corresponding baryon amplitudes and their decomposition in terms of internal spin and orbital angular momentum is explicitly derived. The interaction kernel is truncated to a rainbow-ladder dressed-gluon exchange such that chiral symmetry and its dynamical breaking are correctly implemented. The resulting physical masses agree reasonably with experiment and their evolution with the pion mass compares favorably with lattice calculations. Evidence for the nonsphericity of the Δ resonance is discussed as well.

  6. Delta and Omega masses in a three-quark covariant Faddeev approach

    SciTech Connect

    Sanchis-Alepuz, Helios; Villalba-Chavez, Selym; Alkofer, Reinhard; Eichmann, Gernot

    2011-11-01

    We present the solution of the Poincare-covariant Faddeev equation for the {Delta}(1232) and {Omega}(1672) baryons. The covariant structure of the corresponding baryon amplitudes and their decomposition in terms of internal spin and orbital angular momentum is explicitly derived. The interaction kernel is truncated to a rainbow-ladder dressed-gluon exchange such that chiral symmetry and its dynamical breaking are correctly implemented. The resulting physical masses agree reasonably with experiment and their evolution with the pion mass compares favorably with lattice calculations. Evidence for the nonsphericity of the {Delta} resonance is discussed as well.

  7. Top quark mass measurement in the dilepton channel during the D0 experiment at the Tevatron. Mesure de la masse du quark top dans les canaux di-leptoniques auprès de l’expérience DØ au Tevatron

    SciTech Connect

    Croc, Aurelien

    2011-01-01

    The top quark is the heaviest standard model quark. Discovered in 1995 by the two Tevatron experiments it has atypical properties. In particular its time life is so short that it decays before hadronizing, so the top quark mass could be measured with a high precision. Data collected by the DØ experiment between 2002 and 2009, which represent an integrated luminosity of 5.4 fb⁻¹, are used to measure the top quark mass by using the matrix element method in the three dilepton channels: dielectron, electron--muon and dimuon. The measured mass, 174.0 ± 1.8 (stat.) ± 2.4 (syst.) GeV, is in a good agreement with other measurements and limited by the systematic uncertainties for the first time in these channels. In this thesis different approaches have been studied to improve the accuracy of this measurement: the use of b-quark jet identification in order to optimize the selection of top--anti-top events and a better determination of the main systematic uncertainties. A special attention has been paid to the Monte-Carlo simulation of muons in DØ: the improved smearing procedure for the simulated muons, discussed in this thesis, will be used to increase the accuracy of the top properties measurements as well as the precision of many other DØ measurements.

  8. Measurement of the Top Quark Mass in p anti-p Collisions at s**(1/2) = 1.96-TeV using the Decay Length Technique

    SciTech Connect

    Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara /Cantabria Inst. of Phys.

    2006-12-01

    We report the first measurement of the top quark mass using the decay length technique in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. This technique uses the measured flight distance of the b hadron to infer the mass of the top quark in lepton plus jets events with missing transverse energy. It relies solely on tracking and avoids the jet energy scale uncertainty that is common to all other methods used so far. We apply our novel method to a 695 pb{sup -1} data sample recorded by the CDF II detector at Fermilab and extract a measurement of m{sub t} = 180.7{sub -13.4}{sup +15.5}(stat.) {+-} 8.6 (syst.) GeV/c{sup 2}. While the uncertainty of this result is larger than that of other measurements, the dominant uncertainties in the decay length technique are uncorrelated with those in other methods. This result can help reduce the overall uncertainty when combined with other existing measurements of the top quark mass.

  9. ρ and K* resonances on the lattice at nearly physical quark masses and Nf=2

    NASA Astrophysics Data System (ADS)

    Bali, Gunnar S.; Collins, Sara; Cox, Antonio; Donald, Gordon; Göckeler, Meinulf; Lang, C. B.; Schäfer, Andreas; RQCD Collaboration

    2016-03-01

    Working with a pion mass mπ≈150 MeV , we study π π and K π scattering using two flavors of nonperturbatively improved Wilson fermions at a lattice spacing a ≈0.071 fm . Employing two lattice volumes with linear spatial extents of Ns=48 and Ns=64 points and moving frames, we extract the phase shifts for p -wave π π and K π scattering near the ρ and K* resonances. Comparing our results to those of previous lattice studies, that used pion masses ranging from about 200 MeV up to 470 MeV, we find that the coupling gρ π π appears to be remarkably constant as a function of mπ.

  10. Transverse momentum dependent distribution functions in a covariant parton model approach with quark orbital motion

    SciTech Connect

    Efremov, A. V.; Teryaev, O. V.; Schweitzer, P.; Zavada, P.

    2009-07-01

    Transverse parton momentum dependent distribution functions (TMDs) of the nucleon are studied in a covariant model, which describes the intrinsic motion of partons in terms of a covariant momentum distribution. The consistency of the approach is demonstrated, and model relations among TMDs are studied. As a by-product it is shown how the approach allows to formulate the nonrelativistic limit.

  11. Measurements of the Top Anti-Top Production Cross Section and Top Quark Mass in the Hadronically Decaying Tau + Jets Decay Channel at CDF

    SciTech Connect

    Hare, Daryl Curtis

    2011-01-01

    In this thesis, we present the first exclusive observation of the t-t → hadronic τ + jets decay channel. Using these events, we measure the t-t pair production cross section and the top quark mass in 2.2 fb-1 of data collected with the Collider Detector at Fermilab (CDF). The Tevatron accelerator at Fermilab provides collisions of protons and anti-protons at a center-of-mass energy of √s = 1.96 TeV and is one of only two accelerators in the world with enough energy to produce top quarks. With a branching fraction of nearly 10%, the hadronic τ + jets decay channel is the third largest t-t decay mode, and it has only been minimally explored. This the first measurement of the t-t pair production cross section in this decay channel at CDF and the first measurement of the top quark mass in this decay channel in the world. The analysis introduces a new method to recover the total momentum of the ν produced in the τ decay and an artificial neural network to reduce the contribution from the largest background source, QCD multijet background. The t-t pair production cross section is extracted by minimizing a negative log likelihood function which compares the number of observed events to the number of expected events for a given t-t cross section. The top quark mass is extracted by minimizing a negative log likelihood function built from signal and ii background probabilities which are based on the matrix elements for t-t production and decay and W + 4 parton production, respectively. Using events selected with exactly 1 hadronically decaying τ, exactly 4 jets with at least 1 identified as having originated from a b quark, and large missing transverse energy, we measure the t-t pair production cross section to be 8.8 ± 3.3 (stat.) ± 2.2 (syst.) pb and the top quark mass to be 172.7±9.3 (stat.) ±3.7 (syst.) GeV. We find both values to be in good agreement with

  12. Coherent States of Position-Dependent Mass Oscillator

    NASA Astrophysics Data System (ADS)

    Dehdashti, Shahram; Mahdifar, Ali; Wang, Huaping

    2016-08-01

    In this paper, we study Gazeau-Klauder and displacement-type coherent states of two-dimensional position-dependent mass oscillators, which is called Λ-dependent oscillators and Λ can be interpreted as the curvatures of the spherical and the hyperbolic spaces, on which oscillators are constrained. In addition, we consider the effect of Λ parameter on the physical properties of these coherent states, including minimized Heisenberg uncertainty relation and Mandel's Q parameter. We also elaborate the relation between the curvature of the physical space and the curvature of the Λ-dependent coherent state manifold.

  13. Measurement of Top Quark-Antitop Quark Helicity Fractions and Spin Correlation in Proton-Antiproton Collisions at Center of Mass Energy = TeV

    NASA Astrophysics Data System (ADS)

    Mietlicki, David John

    In the production of top-antitop quark pairs during pp¯ collisions, the spins of the t and t¯ are correlated. This correlation is quantified by the spin correlation coefficient kappa or the fraction of top quarks produced with opposite helicity FOH, which are determined by the QCD interaction mechanism that produces tt¯ pairs. A deviation of the correlation from the predicted value could be an indication of new production mechanisms. We describe a measurement of the tt¯ spin correlation using the lepton plus jets decay channel, where the decay proceeds via tt¯ → W+bW -b¯ → (qq¯'b) (ℓnuℓb¯) or (ℓnuℓb)( qq¯'b¯), in data corresponding to 4.3 fb-1 of integrated luminosity collected with t he CDF detector. In the helicity basis, we find an opposite helicity fraction FOH = 0.80 +/- 0.25stat +/- 0.08 syst and a spin correlation coefficient kappa = 0.60 +/- 0.50stat +/- 0.16 syst, which are in good agreement with the theoretical predictions FOH = 0.70 and kappa = 0.40.

  14. MASS-DEPENDENT BARYON ACOUSTIC OSCILLATION SIGNAL AND HALO BIAS

    SciTech Connect

    Wang Qiao; Zhan Hu

    2013-05-10

    We characterize the baryon acoustic oscillations (BAO) feature in halo two-point statistics using N-body simulations. We find that nonlinear damping of the BAO signal is less severe for halos in the mass range we investigate than for dark matter. The amount of damping depends weakly on the halo mass. The correlation functions show a mass-dependent drop of the halo clustering bias below roughly 90 h {sup -1} Mpc, which coincides with the scale of the BAO trough. The drop of bias is 4% for halos with mass M > 10{sup 14} h {sup -1} M{sub Sun} and reduces to roughly 2% for halos with mass M > 10{sup 13} h {sup -1} M{sub Sun }. In contrast, halo biases in simulations without BAO change more smoothly around 90 h {sup -1} Mpc. In Fourier space, the bias of M > 10{sup 14} h {sup -1} M{sub Sun} halos decreases smoothly by 11% from wavenumber k = 0.012 h Mpc{sup -1} to 0.2 h Mpc{sup -1}, whereas that of M > 10{sup 13} h {sup -1} M{sub Sun} halos decreases by less than 4% over the same range. By comparing the halo biases in pairs of otherwise identical simulations, one with and the other without BAO, we also observe a modulation of the halo bias. These results suggest that precise calibrations of the mass-dependent BAO signal and scale-dependent bias on large scales would be needed for interpreting precise measurements of the two-point statistics of clusters or massive galaxies in the future.

  15. Predictions for the top-quark forward-backward asymmetry at high invariant pair mass using the principle of maximum conformality

    NASA Astrophysics Data System (ADS)

    Wang, Sheng-Quan; Wu, Xing-Gang; Si, Zong-Guo; Brodsky, Stanley J.

    2016-01-01

    The D0 collaboration at FermiLab has recently measured the top-quark pair forward-backward asymmetry in p ¯p →t t ¯X reactions as a function of the t t ¯ invariant mass Mt t ¯. The D0 result for AFB(Mt t ¯>650 GeV ) is smaller than AFB(Mt t ¯) obtained for small values of Mt t ¯, which may indicate an "increasing-decreasing" behavior for AFB(Mt t ¯>Mcut) . This behavior is not explained using conventional renormalization scale setting, or even by a next-to-next-to-leading order (N2LO ) QCD calculation—one predicts a monotonically increasing behavior. In the conventional scale-setting method, one simply guesses a single renormalization scale μr for the argument of the QCD running coupling and then varies it over an arbitrary range. However, the conventional method has inherent difficulties. For example, the resulting perturbative quantum chromodynamics (pQCD) predictions depend on the choice of renormalization scheme, in contradiction to the principle of "renormalization scheme invariance"—predictions for physical observables cannot depend on a theoretical convention. The error estimate obtained by varying μr is unreliable since it is only sensitive to perturbative contributions involving the pQCD β -function. Worse, guessing the renormalization scale gives predictions for precision QED observables which are in contradiction to results obtained using the standard Gell-Mann-Low method. In contrast, if one fixes the scale using the principle of maximum conformality (PMC), the resulting pQCD predictions are renormalization-scheme independent since all of the scheme-dependent {βi}-terms in the QCD perturbative series are resummed into the QCD running couplings at each order. The {βi}-terms at each order can be unambiguously identified using renormalization group methods such as the Rδ method. The PMC then determines the renormalization scales of the running coupling at each order and provides unambiguous scale-fixed and scheme-independent predictions

  16. Inclination Dependence of Estimated Galaxy Masses and Star Formation Rates

    NASA Astrophysics Data System (ADS)

    Hernandez, Betsy; Maller, Ariyeh; McKernan, Barry; Ford, Saavik

    2016-01-01

    We examine the inclination dependence of inferred star formation rates and galaxy mass estimates in the Sloan Digital Sky Survey by combining the disk/bulge de-convolved catalog of Simard et al 2011 with stellar mass estimates catalog of Mendel et al 2014 and star formation rates measured from spectra by Brinchmann et al 2004. We know that optical star formation indicators are reddened by dust, but calculated star formation rates and stellar mass estimates should account for this. However, we find that face-on galaxies have a higher calculated average star formation rates than edge-on galaxies. We also find edge-on galaxies have ,on average, slightly smaller but similar estimated masses to face-on galaxies, suggesting that there are issues with the applied dust corrections for both models.

  17. Top Quark Mass Measurement in the Lepton + Jets Channel Using a Matrix Element Method and \\textit{in situ} Jet Energy Calibration

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR

    2010-10-01

    A precision measurement of the top quark mass m{sub t} is obtained using a sample of t{bar t} events from p{bar p} collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events, a value of m{sub t} = 173.0 {+-} 1.2 GeV/c{sup 2} is measured.

  18. Top Quark Mass Measurement in the lepton+jets Channel Using a Matrix Element Method and in situ Jet Energy Calibration

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Apresyan, A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bauer, G.; Bedeschi, F.; Beecher, D.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Binkley, M.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brau, B.; Brigliadori, L.; Brisuda, A.; Bromberg, C.; Brucken, E.; Bucciantonio, M.; Budagov, J.; Budd, H. S.; Budd, S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Canepa, A.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chou, J. P.; Chung, W. H.; Chung, Y. S.; Ciobanu, C. I.; Ciocci, M. A.; Clark, A.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuenca Almenar, C.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; D'Ascenzo, N.; Datta, M.; de Barbaro, P.; de Cecco, S.; de Lorenzo, G.; Dell'Orso, M.; Deluca, C.; Demortier, L.; Deng, J.; Deninno, M.; Devoto, F.; D'Errico, M.; di Canto, A.; di Ruzza, B.; Dittmann, J. R.; D'Onofrio, M.; Donati, S.; Dong, P.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, D.; Errede, S.; Ershaidat, N.; Eusebi, R.; Fang, H. C.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Ferrazza, C.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Furic, I.; Gallinaro, M.; Galyardt, J.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giunta, M.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gresele, A.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Gunay-Unalan, Z.; Haber, C.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hidas, D.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jha, M. K.; Jindariani, S.; Johnson, W.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, H. W.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kimura, N.; Kirby, M.; Klimenko, S.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Krumnack, N.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; Lazzizzera, I.; Lecompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Lin, C.-J.; Linacre, J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, Q.; Liu, T.; Lockwitz, S.; Lockyer, N. S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Makhoul, K.; Maksimovic, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Martínez-Ballarín, R.; Mastrandrea, P.; Mathis, M.; Mattson, M. E.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Menzione, A.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Norniella, O.; Nurse, E.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.

    2010-12-01

    A precision measurement of the top quark mass mt is obtained using a sample of tt¯ events from pp¯ collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of mt and a parameter ΔJES used to calibrate the jet energy scale in situ. Using a total of 1087 events in 5.6fb-1 of integrated luminosity, a value of mt=173.0±1.2GeV/c2 is measured.

  19. Top Quark Mass Measurement in the lepton+jets Channel Using a Matrix Element Method and in situ Jet Energy Calibration

    SciTech Connect

    Aaltonen, T.; Brucken, E.; Devoto, F.; Mehtala, P.; Orava, R.; Alvarez Gonzalez, B.; Casal, B.; Gomez, G.; Palencia, E.; Rodrigo, T.; Ruiz, A.; Scodellaro, L.; Vila, I.; Vilar, R.; Amerio, S.; Dorigo, T.; Gresele, A.; Lazzizzera, I.; Amidei, D.; Campbell, M.

    2010-12-17

    A precision measurement of the top quark mass m{sub t} is obtained using a sample of tt events from pp collisions at the Fermilab Tevatron with the CDF II detector. Selected events require an electron or muon, large missing transverse energy, and exactly four high-energy jets, at least one of which is tagged as coming from a b quark. A likelihood is calculated using a matrix element method with quasi-Monte Carlo integration taking into account finite detector resolution and jet mass effects. The event likelihood is a function of m{sub t} and a parameter {Delta}{sub JES} used to calibrate the jet energy scale in situ. Using a total of 1087 events in 5.6 fb{sup -1} of integrated luminosity, a value of m{sub t}=173.0{+-}1.2 GeV/c{sup 2} is measured.

  20. Effects of a dressed quark-gluon vertex in vector heavy-light mesons and theory average of the Bc* meson mass

    NASA Astrophysics Data System (ADS)

    Gómez-Rocha, M.; Hilger, T.; Krassnigg, A.

    2016-04-01

    We extend earlier investigations of heavy-light pseudoscalar mesons to the vector case, using a simple model in the context of the Dyson-Schwinger-Bethe-Salpeter approach. We investigate the effects of a dressed quark-gluon vertex in a systematic fashion and illustrate and attempt to quantify corrections beyond the phenomenologically very useful and successful rainbow-ladder truncation. In particular we investigate the dressed quark-photon vertex in such a setup and make a prediction for the experimentally as yet unknown mass of the Bc* , which we obtain at 6.334 GeV well in line with predictions from other approaches. Furthermore, we combine a comprehensive set of results from the theoretical literature. The theoretical average for the mass of the Bc* meson is 6.336 ±0.002 GeV .

  1. Measurement of the top quark mass using template methods on dilepton events in p anti-p collisions at s**(1/2) = 1.96-TeV

    SciTech Connect

    Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2006-02-01

    The authors describe a measurement of the top quark mass from events produced in p{bar p} collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. They identify t{bar t} candidates where both W bosons from the top quarks decay into leptons (e{nu}, {mu}{nu}, or {tau}{nu}) from a data sample of 360 pb{sup -1}. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, t{bar t} longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 {+-} 6.0(stat.) {+-} 4.1(syst.) GeV/c{sup 2}.

  2. Measurement of the front back asymmetry in top-antitop quark pairs produced in proton-antiproton collisions at center of mass energy = 1.96 TeV

    SciTech Connect

    Schwarz, Thomas A.; /Michigan U.

    2006-01-01

    Quarks, along with leptons and force carrying particles, are predicted by the Standard Model to be the fundamental constituents of nature. In distinction from the leptons, the quarks interact strongly through the chromodynamic force and are bound together within the hadrons. The familiar proton and neutron are bound states of the light ''up'' and ''down'' quarks. The most massive quark by far, the ''top'' quark, was discovered by the CDF and D0 experiments in March, 1995. The new quark was observed in p{bar p} collisions at 1.8 TeV at the Fermilab Tevatron. The mass of the top quark was measured to be 176 {+-} 13 GeV/c{sup 2} and the cross section 6.8{sub -2.4}{sup +3.6} pb. It is the Q = 2/3, T{sub 3} = +1/2 member of the third generation weak-isospin doublet along with the bottom quark. The top quark is the final Standard Model quark to be discovered. Along with whatever is responsible for electroweak symmetry breaking, top quark physics is considered one of the least understood sectors of the Standard Model and represents a front line of our understanding of particle physics. Currently, the only direct measurements of top quark properties come from the CDF and D0 experiments observing p{bar p} collisions at the Tevatron. Top quark production at the Tevatron is almost exclusively by quark-antiquark annihilation, q{bar q} {yields} t{bar t} (85%), and gluon fusion, gg {yields} t{bar t} (15%), mediated by the strong force. The theoretical cross-section for this process is {sigma}{sub t{bar t}} = 6.7 {+-} 0.8 pb for m{sub t} = 175 GeV/c{sup 2}. Top quarks can also be produced at the Tevatron via q{bar b}{prime} {yields} tb and qg {yields} q{prime}tb through the weak interaction. The cross section for these processes is lower (3pb) and the signal is much more difficult to isolate as backgrounds are much higher. The top quark is predicted to decay almost exclusively into a W-boson and a bottom quark (t {yields} Wb). The total decay width t {yields} Wb is {Lambda} = 1

  3. ENVIRONMENTAL DEPENDENCE OF OTHER GALAXY PROPERTIES FOR HIGH STELLAR MASS AND LOW STELLAR MASS GALAXIES

    SciTech Connect

    Deng Xinfa; Wen Xiaoqing; Xu Jianying; Ding Yingping; Huang Tong

    2010-06-10

    At a stellar mass of 3 x 10{sup 10} M {sub {Theta}} we divide the volume-limited Main galaxy sample of the Sloan Digital Sky Survey Data Release 6 (SDSS DR6) into two distinct families and explore the environmental dependence of galaxy properties for High Stellar Mass (HSM) and Low Stellar Mass (LSM) galaxies. It is found that for HSM and LSM galaxies, the environmental dependence of some typical galaxy properties, such as color, morphologies, and star formation activities, is still very strong, which at least shows that the stellar mass is not fundamental in correlations between galaxy properties and the environment. We also note that the environmental dependence of the size for HSM and LSM galaxies is fairly weak, which is mainly due to the galaxy size being insensitive to environment.

  4. A Measurement of the Top Quark Mass with the D0 Detector at s**(1/2) = 1.96-TeV using the Matrix Element Method

    SciTech Connect

    Kroeninger, Kevin Alexander; /Bonn U.

    2004-04-01

    Using a data set of 158 and 169 pb{sup -1} of D0 Run-II data in the electron and muon plus jets channel, respectively, the top quark mass has been measured using the Matrix Element Method. The method and its implementation are described. Its performance is studied in Monte Carlo using ensemble tests and the method is applied to the Moriond 2004 data set.

  5. The quark-gluon vertex in Landau gauge QCD: Its role in dynamical chiral symmetry breaking and quark confinement

    NASA Astrophysics Data System (ADS)

    Alkofer, Reinhard; Fischer, Christian S.; Llanes-Estrada, Felipe J.; Schwenzer, Kai

    2009-01-01

    The infrared behavior of the quark-gluon vertex of quenched Landau gauge QCD is studied by analyzing its Dyson-Schwinger equation. Building on previously obtained results for Green functions in the Yang-Mills sector, we analytically derive the existence of power-law infrared singularities for this vertex. We establish that dynamical chiral symmetry breaking leads to the self-consistent generation of components of the quark-gluon vertex forbidden when chiral symmetry is forced to stay in the Wigner-Weyl mode. In the latter case the running strong coupling assumes an infrared fixed point. If chiral symmetry is broken, either dynamically or explicitly, the running coupling is infrared divergent. Based on a truncation for the quark-gluon vertex Dyson-Schwinger equation which respects the analytically determined infrared behavior, numerical results for the coupled system of the quark propagator and vertex Dyson-Schwinger equation are presented. The resulting quark mass function as well as the vertex function show only a very weak dependence on the current quark mass in the deep infrared. From this we infer by an analysis of the quark-quark scattering kernel a linearly rising quark potential with an almost mass independent string tension in the case of broken chiral symmetry. Enforcing chiral symmetry does lead to a Coulomb type potential. Therefore, we conclude that chiral symmetry breaking and confinement are closely related. Furthermore, we discuss aspects of confinement as the absence of long-range van der Waals forces and Casimir scaling. An examination of experimental data for quarkonia provides further evidence for the viability of the presented mechanism for quark confinement in the Landau gauge.

  6. The moment ⟨x ⟩u -d of the nucleon from Nf=2 lattice QCD down to nearly physical quark masses

    NASA Astrophysics Data System (ADS)

    Bali, Gunnar S.; Collins, Sara; Gläßle, Benjamin; Göckeler, Meinulf; Najjar, Johannes; Rödl, Rudolf H.; Schäfer, Andreas; Schiel, Rainer W.; Sternbeck, André; Söldner, Wolfgang

    2014-10-01

    We present an update of our analysis [1] which includes additional ensembles at different quark masses, lattice spacings and volumes, all with high statistics. We use Nf=2 mass-degenerate quark flavors, employing the nonperturbatively improved clover action. The lattice matrix elements are converted to the MS ¯ scheme via renormalization factors determined nonperturbatively in the RI' -MOM scheme. We have systematically investigated excited state contributions, in particular, at the smallest, near physical, pion mass. While our results (with much increased precision) are consistent with Ref. [1], comparing to previous determinations we find that excited state contributions can be significant if the quark smearing is not suitably optimized, in agreement with other recent studies. The difference with respect to the value for ⟨x ⟩u-d extracted from experimental data is reduced but not resolved. Using lattice sizes in the range L mπ˜3.4 - 6.7 , no significant finite volume effects have been observed. Performing a controlled continuum limit that may remove the discrepancy will require simulations at lattice spacings a <0.06 fm .

  7. Calculation of mass of Y(4140) by introducing mixed molecule state in quark model

    NASA Astrophysics Data System (ADS)

    Chen, Xiaozhao; Lü, Xiaofu; Shi, Renbin; Guo, Xiurong

    2016-08-01

    Using the general form of the Bethe-Salpeter wave functions for the bound states consisting of two vector fields given in our previous work, we investigate the molecular state composed of Ds*+ Ds*-. However, for the SU(3) symmetry the component Ds*+ Ds*- is coupled with the other components D*0D bar * 0 and D*+D*-. Then we interpret the internal structure of the observed Y (4140) state as a mixed state of pure molecule states D*0D bar * 0, D*+D*- and Ds*+ Ds*-with quantum numbers JP =0+. In this paper, the operator product expansion is used to introduce the nonperturbative contribution from the vacuum condensates into the interaction between two heavy mesons. The calculated mass of Y (4140) is consistent with the experimental value, and we conclude that it is a more reasonable scenario to explain the structure of Y (4140) as a mixture of pure molecule states.

  8. Power corrections to event shapes with mass-dependent operators

    NASA Astrophysics Data System (ADS)

    Mateu, Vicent; Stewart, Iain W.; Thaler, Jesse

    2013-01-01

    We introduce an operator depending on the “transverse velocity” r that describes the effect of hadron masses on the leading 1/Q power correction to event-shape observables. Here, Q is the scale of the hard collision. This work builds on earlier studies of mass effects by Salam and Wicke [J. High Energy Phys. 05 (2001) 061JHEPFG1029-8479] and of operators by Lee and Sterman [Phys. Rev. D 75, 014022 (2007)PRVDAQ1550-7998]. Despite the fact that different event shapes have different hadron mass dependence, we provide a simple method to identify universality classes of event shapes whose power corrections depend on a common nonperturbative parameter. We also develop an operator basis to show that at a fixed value of Q, the power corrections for many classic observables can be determined by two independent nonperturbative matrix elements at the 10% level. We compute the anomalous dimension of the transverse velocity operator, which is multiplicative in r and causes the power correction to exhibit nontrivial dependence on Q. The existence of universality classes and the relevance of anomalous dimensions are reproduced by the hadronization models in Pythia 8 and Herwig​+​+, though the two programs differ in the values of their low-energy matrix elements.

  9. The dependence of convective core overshooting on stellar mass

    NASA Astrophysics Data System (ADS)

    Claret, A.; Torres, G.

    2016-07-01

    Context. Convective core overshooting extends the main-sequence lifetime of a star. Evolutionary tracks computed with overshooting are very different from those that use the classical Schwarzschild criterion, which leads to rather different predictions for the stellar properties. Attempts over the last two decades to calibrate the degree of overshooting with stellar mass using detached double-lined eclipsing binaries have been largely inconclusive, mainly because of a lack of suitable observational data. Aims: We revisit the question of a possible mass dependence of overshooting with a more complete sample of binaries, and examine any additional relation there might be with evolutionary state or metal abundance Z. Methods: We used a carefully selected sample of 33 double-lined eclipsing binaries strategically positioned in the H-R diagram with accurate absolute dimensions and component masses ranging from 1.2 to 4.4 M⊙. We compared their measured properties with stellar evolution calculations to infer semi-empirical values of the overshooting parameter αov for each star. Our models use the common prescription for the overshoot distance dov = αovHp, where Hp is the pressure scale height at the edge of the convective core as given by the Schwarzschild criterion, and αov is a free parameter. Results: We find a relation between αov and mass, which is defined much more clearly than in previous work, and indicates a significant rise up to about 2 M⊙ followed by little or no change beyond this mass. No appreciable dependence is seen with evolutionary state at a given mass, or with metallicity at a given mass although the stars in our sample span a range of a factor of ten in [Fe/H], from -1.01 to + 0.01.

  10. Contribution of a heavy singlet quark to the mass differences {Delta}m{sub k}{sup o}, {Delta}m{sub Bd}, and {Delta}m{sub Bs} and to the CP-violation parameter {epsilon}{sub K}

    SciTech Connect

    Kopnin, P. N.

    2008-08-15

    It is shown that, within the Standard Model extended by including a singlet quark heavy enough to prevent its direct detection at LHC, the mass differences {Delta}m{sub B{sub d}} and {Delta}m{sub Bs} and the parameter of CP violation in K-meson oscillations, {epsilon}{sub K}, acquire universal corrections of about 5 to 10%. Implicit experimental constraints on the mass of this new quark are discussed.

  11. The Mass-Dependence of Cadmium Isotope Fractionation During Evaporation

    NASA Astrophysics Data System (ADS)

    Rehkamper, M.; Wombacher, F.; Mezger, K.; Wiechert, U.

    2002-12-01

    Isotope fractionation laws relate the isotope fractionation factor αA of one isotope ratio to the fractionation factor αB of a second isotope ratio of the same element with a fractionation exponent β, such that αA = αBβ. In a recent paper, Young et al. (GCA 66, 1095-1104 (2002)) inferred that kinetic and equilibrium isotope fractionations are characterized by different mass functions, such that βkin is not equal to βeq. As a consequence, kinetic isotope fractionation is expected to produce fractionation lines in three isotope space that are different from those generated by equilibrium fractionation processes. Young et al. furthermore stated that the variability in mass-dependent fractionation laws may be sufficient to account for the negative Δ17O of tropospheric O2 and the Δ17O anomalies of minerals in SNC meteorites. Such variations have otherwise been interpreted as evidence of non-mass dependant isotope fractionations (Luz et al., Nature 400, 547-550 (1999); Farquhar et al., Science 280, 1589-1582 (1998)). In the present study, we investigated the mass-dependence of isotope fractionation by evaluating the results of evaporation experiments that produced very large differences in Cd isotope compositions (up to about 100‰ ). In these experiments, liquid Cd was evaporated into a vacuum at a temperature of about 200°C. The metal residues remaining after evaporation were analyzed for their Cd isotope composition by multiple-collector inductively coupled plasma-mass spectrometry (MC-ICPMS) relative to the unfractionated starting material. The precision of the measurements is sufficient to clearly distinguish between different fractionation mechanisms. In linearized three-isotope space, the residual Cd metals plot on fractionation lines (e.g., with a slope β = 2.049 +/- 2 for 106}Cd/{114Cd vs. 110}Cd/{114Cd) that are intermediate between the kinetic (β = 2.036) and the equilibrium (β = 2.075) fractionation lines. This can be explained by an

  12. Displacement operator for quantum systems with position-dependent mass

    SciTech Connect

    Costa Filho, R. N.; Almeida, M. P.; Farias, G. A.; Andrade, J. S. Jr.

    2011-11-15

    A translation operator is introduced to describe the quantum dynamics of a position-dependent mass particle in a null or constant potential. From this operator, we obtain a generalized form of the momentum operator as well as a unique commutation relation for x and p{sub {gamma}}. Such a formalism naturally leads to a Schroedinger-like equation that is reminiscent of wave equations typically used to model electrons with position-dependent (effective) masses propagating through abrupt interfaces in semiconductor heterostructures. The distinctive features of our approach are demonstrated through analytical solutions calculated for particles under null and constant potentials like infinite wells in one and two dimensions and potential barriers.

  13. A Stellar-mass-dependent Drop in Planet Occurrence Rates

    NASA Astrophysics Data System (ADS)

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-01

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R ⊕) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ~10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  14. A STELLAR-MASS-DEPENDENT DROP IN PLANET OCCURRENCE RATES

    SciTech Connect

    Mulders, Gijs D.; Pascucci, Ilaria; Apai, Dániel

    2015-01-10

    The Kepler spacecraft has discovered a large number of planets with up to one-year periods and down to terrestrial sizes. While the majority of the target stars are main-sequence dwarfs of spectral type F, G, and K, Kepler covers stars with effective temperatures as low as 2500 K, which corresponds to M stars. These cooler stars allow characterization of small planets near the habitable zone, yet it is not clear if this population is representative of that around FGK stars. In this paper, we calculate the occurrence of planets around stars of different spectral types as a function of planet radius and distance from the star and show that they are significantly different from each other. We further identify two trends. First, the occurrence of Earth- to Neptune-sized planets (1-4 R {sub ⊕}) is successively higher toward later spectral types at all orbital periods probed by Kepler; planets around M stars occur twice as frequently as around G stars, and thrice as frequently as around F stars. Second, a drop in planet occurrence is evident at all spectral types inward of a ∼10 day orbital period, with a plateau further out. By assigning to each spectral type a median stellar mass, we show that the distance from the star where this drop occurs is stellar mass dependent, and scales with semi-major axis as the cube root of stellar mass. By comparing different mechanisms of planet formation, trapping, and destruction, we find that this scaling best matches the location of the pre-main-sequence co-rotation radius, indicating efficient trapping of migrating planets or planetary building blocks close to the star. These results demonstrate the stellar-mass dependence of the planet population, both in terms of occurrence rate and of orbital distribution. The prominent stellar-mass dependence of the inner boundary of the planet population shows that the formation or migration of planets is sensitive to the stellar parameters.

  15. Top Quark Properties

    SciTech Connect

    Peters, Yvonne

    2011-12-01

    Since its discovery in 1995 by the CDF and D0 collaborations at the Fermilab Tevatron collider, the top quark has undergone intensive studies. Besides the Tevatron experiments, with the start of the LHC in 2010 a top quark factory started its operation. It is now possible to measure top quark properties simultaneously at four different experiments, namely ATLAS and CMS at LHC and CDF and D0 at Tevatron. Having collected thousands of top quarks each, several top quark properties have been measured precisely, while others are being measured for the first time. In this article, recent measurements of top quark properties from ATLAS, CDF, CMS and D0 are presented, using up to 5.4 fb{sup -1} of integrated luminosity at the Tevatron and 1.1 fb{sup -1} at the LHC. In particular, measurements of the top quark mass, mass difference, foward backward charge asymmetry, t{bar t} spin correlations, the ratio of branching fractions, W helicity, anomalous couplings, color flow and the search for flavor changing neutral currents are discussed.

  16. Top quark physics: Future Measurements

    SciTech Connect

    Frey, Raymond; Gerdes, David; Jaros, John; Vejcik, Steve; Berger, Edmond L.; Chivukula, R. Sekhar; Cuypers, Frank; Drell, Persis S.; Fero, Michael; Hadley, Nicholas; Han, Tao; Heinson, Ann P.; Knuteson, Bruce; Larios, Francisco; Miettinen, Hannu; Orr, Lynne H.; Peskin, Michael E.; Rizzo, Thomas; Sarid, Uri; Schmidt, Carl; Stelzer, Tim; Sullivan, Zack

    1996-12-31

    We discuss the study of the top quark at future experiments and machines. Top's large mass makes it a unique probe of physics at the natural electroweak scale. We emphasize measurements of the top quark's mass, width, and couplings, as well as searches for rare or nonstandard decays, and discuss the complementary roles played by hadron and lepton colliders.

  17. A model for QCD at high density and large quark mass

    SciTech Connect

    De Pietri, Roberto; Feo, Alessandra; Seiler, Erhard; Stamatescu, Ion-Olimpiu

    2007-12-01

    We study the high density region of QCD within an effective model obtained in the frame of the hopping parameter expansion and choosing Polyakov-type loops as the main dynamical variables representing the fermionic matter. To get a first idea of the phase structure, the model is analyzed in strong coupling expansion and using a mean field approximation. In numerical simulations, the model still shows the so-called sign problem, a difficulty peculiar to nonzero chemical potential, but it permits the development of algorithms which ensure a good overlap of the Monte Carlo ensemble with the true one. We review the main features of the model and present calculations concerning the dependence of various observables on the chemical potential and on the temperature, in particular, of the charge density and the diquark susceptibility, which may be used to characterize the various phases expected at high baryonic density. We obtain in this way information about the phase structure of the model and the corresponding phase transitions and crossover regions, which can be considered as hints for the behavior of nonzero density QCD.

  18. Predicting charmonium and bottomonium spectra with a quark harmonic oscillator

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Badavi, F. F.; Townsend, L. W.

    1986-01-01

    The nonrelativistic quark model is applied to heavy (nonrelativistic) meson (two-body) systems to obtain sufficiently accurate predictions of the spin-averaged mass levels of the charmonium and bottomonium spectra as an example of the three-dimensional harmonic oscillator. The present calculations do not include any spin dependence, but rather, mass values are averaged for different spins. Results for a charmed quark mass value of 1500 MeV/c-squared show that the simple harmonic oscillator model provides good agreement with experimental values for 3P states, and adequate agreement for the 3S1 states.

  19. Top quark studies at hadron colliders

    SciTech Connect

    Sinervo, P.K.; CDF Collaboration

    1996-08-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag {ital b} quark jets in candidate events. The most recent measurements of top quark properties by the CDF and D{null} collaborations are reviewed, including the top quark cross section, mass, branching fractions and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  20. Heavy quarks in the jet calculus

    SciTech Connect

    Jones, L.M.

    1983-07-01

    In this paper we explore a method for treating heavy quarks such as c and b quarks within the jet calculus. These quarks are differentiated from the more common u, d, and s quarks by the requirement that the gluons never branch into heavy-quark pairs during the jet development. We compute and discuss the charmed-quark ''propagators''; the x distribution of colorless clusters containing a charmed quark, a noncharmed antiquark, and gluons; and the mass distribution of the parent partons giving rise to these colorless clusters.

  1. Top quark studies at hadron colliders

    SciTech Connect

    Sinervo, P.K.

    1997-01-01

    The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

  2. Einstein's Gravitational Field Approach to Dark Matter and Dark Energy-Geometric Particle Decay into the Vacuum Energy Generating Higgs Boson and Heavy Quark Mass

    NASA Astrophysics Data System (ADS)

    Christensen, Walter James

    2015-08-01

    During an interview at the Niels Bohr Institute David Bohm stated, "according to Einstein, particles should eventually emerge as singularities, or very strong regions of stable pulses of (the gravitational) field" [1]. Starting from this premise, we show spacetime, indeed, manifests stable pulses (n-valued gravitons) that decay into the vacuum energy to generate all three boson masses (including Higgs), as well as heavy-quark mass; and all in precise agreement with the 2010 CODATA report on fundamental constants. Furthermore, our relativized quantum physics approach (RQP) answers to the mystery surrounding dark energy, dark matter, accelerated spacetime, and why ordinary matter dominates over antimatter.

  3. Infrared divergences, mass shell singularities and gauge dependence of the dynamical fermion mass

    NASA Astrophysics Data System (ADS)

    Das, Ashok K.; Frenkel, J.; Schubert, C.

    2013-03-01

    We study the behavior of the dynamical fermion mass when infrared divergences and mass shell singularities are present in a gauge theory. In particular, in the massive Schwinger model in covariant gauges we find that the pole of the fermion propagator is divergent and gauge dependent at one loop, but the leading singularities cancel in the quenched rainbow approximation. On the other hand, in physical gauges, we find that the dynamical fermion mass is finite and gauge independent at least up to one loop.

  4. Yet another position-dependent mass quantum model

    SciTech Connect

    Lima, Jonas R. F.; Vieira, M.; Furtado, C.; Moraes, F.; Filgueiras, Cleverson

    2012-07-15

    The quantum dynamics of particles with mass dependent on the position is a problem of interest since the effective-mass approach to charge carriers in conductors and semiconductors began to be used. These problems have been solved using the Hamiltonian H=(1/2)m{sup {alpha}}(x)pm{sup {beta}}(x)pm{sup {alpha}}(x), where {alpha} and {beta} are real parameters which satisfy the condition 2{alpha}+{beta}=-1. It has been verified that the choice {alpha}= 0, {beta}=-1 is compatible with Galilean invariance. In this work we propose a new Hamiltonian, H-caret=(1/6)m-caret(x-caret){sup -1}p-caret{sup 2}+p-caretm-caret(x-caret){sup -1}p-caret+p{sup 2} m-caret(x-caret){sup -1}, to describe variable mass systems. We considered every permutation among the operators, taking into account that the mass is now an operator. We verified that this Hamiltonian is Hermitian and is compatible with Galilean invariance. For comparison, we used both Hamiltonians to calculate the band structure for a quantum particle with mass varying periodically. Although qualitatively equivalent, the results turn out to produce different numerical values.

  5. Curvature of the critical line on the plane of quark chemical potential and pseudoscalar meson mass for three-flavor QCD

    NASA Astrophysics Data System (ADS)

    Jin, Xiao-Yong; Kuramashi, Yoshinobu; Nakamura, Yoshifumi; Takeda, Shinji; Ukawa, Akira

    2015-12-01

    We investigate the phase structure of three-flavor QCD in the presence of finite quark chemical potential μ /T ≲1.2 by using the nonperturbatively O (a ) improved Wilson fermion action on lattices with a fixed temporal extent Nt=6 and varied spatial linear extents Ns=8 , 10, 12. Especially, we focus on locating the critical end point that characterizes the phase structure, and extracting the curvature of the critical line on the μ -mπ plane. For Wilson-type fermions, the correspondence between bare parameters and physical parameters is indirect. Hence we present a strategy to transfer the bare parameter phase structure to the physical one, in order to obtain the curvature. Our conclusion is that the curvature is positive. This implies that, if one starts from a quark mass in the region of crossover at zero chemical potential, one would encounter a first-order phase transition when one raises the chemical potential.

  6. Light quark spin symmetry in Zb resonances?

    NASA Astrophysics Data System (ADS)

    Voloshin, M. B.

    2016-04-01

    It is argued that the recent Belle data, consistent with no activity in the spectrum of the B*B ¯ +B B¯ * pairs at the mass of the Zb(10650 ) resonance, imply that the part of the interaction between heavy mesons that depends on the total spin of the light quark and antiquark is strongly suppressed. In particular, this part appears to be significantly weaker than can be inferred from pion exchange. If confirmed by future more detailed data, the symmetry with respect to the light quark spins, in combination with the heavy quark spin symmetry, would imply existence of four additional IG=1- resonances at the thresholds for heavy meson-antimeson pairs.

  7. Transport properties of quark and gluon plasmas

    SciTech Connect

    Heiselberg, H.

    1993-12-01

    The kinetic properties of relativistic quark-gluon and electron-photon plasmas are described in the weak coupling limit. The troublesome Rutherford divergence at small scattering angles is screened by Debye screening for the longitudinal or electric part of the interactions. The transverse or magnetic part of the interactions is effectively screened by Landau damping of the virtual photons and gluons transferred in the QED and QCD interactions respectively. Including screening a number of transport coefficients for QCD and QED plasmas can be calculated to leading order in the interaction strength, including rates of momentum and thermal relaxation, electrical conductivity, viscosities, flavor and spin diffusion of both high temperature and degenerate plasmas. Damping of quarks and gluons as well as color diffusion in quark-gluon plasmas is, however, shown not to be sufficiently screened and the rates depends on an infrared cut-off of order the ``magnetic mass,`` m{sub mag} {approximately} g{sup 2}T.

  8. Single Spin Asymmetry in Strongly Correlated Quark Model

    SciTech Connect

    Musulmanbekov, G.

    2007-06-13

    The Single Transverse - Spin Asymmetry (SSA) is analysed in the framework of the Strongly Correlated Quark Model proposed by author, where the proton spin emerges from the orbital momenta of quark and qluon condensates circulating around the valence quarks. It is shown that dominating factors of appearance of SSA are the orbiting around the valence quarks sea quark and qluon condensates and spin dependent quark-quark cross sections.

  9. Mean-field theory of baryonic matter for QCD in the large Nc and heavy quark mass limits

    NASA Astrophysics Data System (ADS)

    Adhikari, Prabal; Cohen, Thomas D.

    2013-11-01

    We discuss theoretical issues pertaining to baryonic matter in the combined heavy-quark and large Nc limits of QCD. Witten's classic argument that baryons and interacting systems of baryons can be described in a mean-field approximation with each of the quarks moving in an average potential due to the remaining quarks is heuristic. It is important to justify this heuristic description for the case of baryonic matter since systems of interacting baryons are intrinsically more complicated than single baryons due to the possibility of hidden color states—states in which the subsystems making up the entire baryon crystal are not color-singlet nucleons but rather colorful states coupled together to make a color-singlet state. In this work, we provide a formal justification of this heuristic prescription. In order to do this, we start by taking the heavy quark limit, thus effectively reducing the problem to a many-body quantum mechanical system. This problem can be formulated in terms of integrals over coherent states, which for this problem are simple Slater determinants. We show that for the many-body problem, the support region for these integrals becomes narrow at large Nc, yielding an energy which is well approximated by a single coherent state—that is a mean-field description. Corrections to the energy are of relative order 1/Nc. While hidden color states are present in the exact state of the heavy quark system, they only influence the interaction energy below leading order in 1/Nc.

  10. Heavy quark results at D0

    SciTech Connect

    Fein, D.K.; D0 Collaboration

    1997-01-01

    Recent results in heavy quark physics from the D0 experiment at the Fermilab Tevatron Collider are reported. Topics included are top quark production and mass determination, bottom production and correlations, and charmonium production. 20 refs., 10 figs., 2 tabs.

  11. Testing the color charge and mass dependence of parton energy loss with heavy-to-light ratios at BNL RHIC and CERN LHC

    SciTech Connect

    Armesto, Nestor; Dainese, Andrea; Salgado, Carlos A.; Wiedemann, Urs Achim

    2005-03-01

    The ratio of nuclear modification factors of high-p{sub T} heavy-flavored mesons to light-flavored hadrons ('heavy-to-light ratio') in nucleus-nucleus collisions tests the partonic mechanism expected to underlie jet quenching. Heavy-to-light ratios are mainly sensitive to the mass and color-charge dependences of medium-induced parton energy loss. Here, we assess the potential for identifying these two effects in D and B meson production at RHIC and at the LHC. To this end, we supplement the perturbative QCD factorized formalism for leading hadron production with radiative parton energy loss. For D meson spectra at high but experimentally accessible transverse momentum (10 < or approx. p{sub T} < or approx. 20 GeV) in Pb-Pb collisions at the LHC, we find that charm quarks behave essentially like light quarks. However, since light-flavored hadron yields are dominated by gluon parents, the heavy-to-light ratio of D mesons is a sensitive probe of the color-charge dependence of parton energy loss. In contrast, due to the larger b quark mass, the medium modification of B mesons in the same kinematical regime provides a sensitive test of the mass dependence of parton energy loss. At RHIC energies, the strategies for identifying and disentangling the color charge and mass dependence of parton energy loss are more involved because of the smaller kinematical range accessible. We argue that at RHIC, the kinematical regime best suited for such an analysis of D mesons is 7 < or approx. p{sub T} < or approx. 12 GeV, whereas the study of lower transverse momenta is further complicated due to the known dominant contribution of additional, particle species dependent, nonperturbative effects.

  12. The mass and speed dependence of meteor air plasma temperatures

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.; Wilson, Michael A.; Schaller, Emily L.

    2004-01-01

    The speed and mass dependence of meteor air plasma temperatures is perhaps the most important data needed to understand how small meteoroids chemically change the ambient atmosphere in their path and enrich the ablated meteoric organic matter with oxygen. Such chemistry can play an important role in creating prebiotic compounds. The excitation conditions in various air plasma emissions were measured from high-resolution optical spectra of Leonid storm meteors during NASA's Leonid Multi-Instrument Aircraft Campaign. This was the first time a sufficient number and range of temperature measurements were obtained to search for meteoroid mass and speed dependencies. We found slight increases in temperature with decreasing altitude, but otherwise nearly constant values for meteoroids with speeds between 35 and 72 km/s and masses between 10(-5) g and 1 g. We conclude that faster and more massive meteoroids produce a larger emission volume, but not a higher air plasma temperature. We speculate that the meteoric plasma may be in multiphase equilibrium with the ambient atmosphere, which could mean lower plasma temperatures in a CO(2)-rich early Earth atmosphere.

  13. Quark propagators in confinement and deconfinement phases

    SciTech Connect

    Hamada, Masatoshi; Yahiro, Masanobu; Kouno, Hiroaki; Nakamura, Atsushi; Saito, Takuya

    2010-05-01

    We study quark propagators near the confinement/deconfinement phase transition temperature in quenched-lattice simulation of QCD. We find that there is no qualitative change for the quark propagators in both phases. In the confinement phase, those effective quark masses in units of the critical temperature behave as a constant as a function of the temperature, while above the critical temperature, the value of the effective quark mass drops to circa half value.

  14. Charm physics with a nonperturbatively determined relativistic heavy quark action

    NASA Astrophysics Data System (ADS)

    Lin, Huey-Wen

    the scale determined by r0 = 0.5 fm, 40% smaller than the experimental value but 10% higher than the calculation using one-loop coefficients at the same lattice spacing. The DsJ spectrum is also studied in this work. The mD*s-m Ds splitting is 123(3) MeV, 14% lower than the experimental result. We find the heavy quark mass dependence of the parity splitting is weak. Finally, the prediction for the charm quark mass in the MS scheme is 1.314(18) GeV, where only the statistical error is shown.

  15. Determination of |V(us)|| from a lattice QCD calculation of the K → πℓν semileptonic form factor with physical quark masses.

    PubMed

    Bazavov, A; Bernard, C; Bouchard, C M; Detar, C; Du, Daping; El-Khadra, A X; Foley, J; Freeland, E D; Gámiz, E; Gottlieb, Steven; Heller, U M; Kim, Jongjeong; Kronfeld, A S; Laiho, J; Levkova, L; Mackenzie, P B; Neil, E T; Oktay, M B; Qiu, Si-Wei; Simone, J N; Sugar, R; Toussaint, D; Van de Water, R S; Zhou, Ran

    2014-03-21

    We calculate the kaon semileptonic form factor f+(0) from lattice QCD, working, for the first time, at the physical light-quark masses. We use gauge configurations generated by the MILC Collaboration with Nf = 2 + 1 + 1 flavors of sea quarks, which incorporate the effects of dynamical charm quarks as well as those of up, down, and strange. We employ data at three lattice spacings to extrapolate to the continuum limit. Our result, f+(0) = 0.9704(32), where the error is the total statistical plus systematic uncertainty added in quadrature, is the most precise determination to date. Combining our result with the latest experimental measurements of K semileptonic decays, one obtains the Cabibbo-Kobayashi-Maskawa matrix element |V(us)| = 0.22290(74)(52), where the first error is from f+(0) and the second one is from experiment. In the first-row test of Cabibbo-Kobayashi-Maskawa unitarity, the error stemming from |V(us)| is now comparable to that from |V(ud)|. PMID:24702353

  16. RESOLVE and ECO: The Halo Mass-dependent Shape of Galaxy Stellar and Baryonic Mass Functions

    NASA Astrophysics Data System (ADS)

    Eckert, Kathleen D.; Kannappan, Sheila J.; Stark, David V.; Moffett, Amanda J.; Berlind, Andreas A.; Norris, Mark A.

    2016-06-01

    In this work, we present galaxy stellar and baryonic (stars plus cold gas) mass functions (SMF and BMF) and their halo mass dependence for two volume-limited data sets. The first, RESOLVE-B, coincides with the Stripe 82 footprint and is extremely complete down to baryonic mass M bary ∼ 109.1 M ⊙, probing the gas-rich dwarf regime below M bary ∼ 1010 M ⊙. The second, ECO, covers a ∼40× larger volume (containing RESOLVE-A) and is complete to M bary ∼ 109.4 M ⊙. To construct the SMF and BMF we implement a new “cross-bin sampling” technique with Monte Carlo sampling from the full likelihood distributions of stellar or baryonic mass. Our SMFs exhibit the “plateau” feature starting below M star ∼ 1010 M ⊙ that has been described in prior work. However, the BMF fills in this feature and rises as a straight power law below ∼1010 M ⊙, as gas-dominated galaxies become the majority of the population. Nonetheless, the low-mass slope of the BMF is not as steep as that of the theoretical dark matter halo MF. Moreover, we assign group halo masses by abundance matching, finding that the SMF and BMF, separated into four physically motivated halo mass regimes, reveal complex structure underlying the simple shape of the overall MFs. In particular, the satellite MFs are depressed below the central galaxy MF “humps” in groups with mass <1013.5 M ⊙ yet rise steeply in clusters. Our results suggest that satellite destruction and stripping are active from the point of nascent group formation. We show that the key role of groups in shaping MFs enables reconstruction of a given survey’s SMF or BMF based on its group halo mass distribution.

  17. RESOLVE and ECO: The Halo Mass-dependent Shape of Galaxy Stellar and Baryonic Mass Functions

    NASA Astrophysics Data System (ADS)

    Eckert, Kathleen D.; Kannappan, Sheila J.; Stark, David V.; Moffett, Amanda J.; Berlind, Andreas A.; Norris, Mark A.

    2016-06-01

    In this work, we present galaxy stellar and baryonic (stars plus cold gas) mass functions (SMF and BMF) and their halo mass dependence for two volume-limited data sets. The first, RESOLVE-B, coincides with the Stripe 82 footprint and is extremely complete down to baryonic mass M bary ˜ 109.1 M ⊙, probing the gas-rich dwarf regime below M bary ˜ 1010 M ⊙. The second, ECO, covers a ˜40× larger volume (containing RESOLVE-A) and is complete to M bary ˜ 109.4 M ⊙. To construct the SMF and BMF we implement a new “cross-bin sampling” technique with Monte Carlo sampling from the full likelihood distributions of stellar or baryonic mass. Our SMFs exhibit the “plateau” feature starting below M star ˜ 1010 M ⊙ that has been described in prior work. However, the BMF fills in this feature and rises as a straight power law below ˜1010 M ⊙, as gas-dominated galaxies become the majority of the population. Nonetheless, the low-mass slope of the BMF is not as steep as that of the theoretical dark matter halo MF. Moreover, we assign group halo masses by abundance matching, finding that the SMF and BMF, separated into four physically motivated halo mass regimes, reveal complex structure underlying the simple shape of the overall MFs. In particular, the satellite MFs are depressed below the central galaxy MF “humps” in groups with mass <1013.5 M ⊙ yet rise steeply in clusters. Our results suggest that satellite destruction and stripping are active from the point of nascent group formation. We show that the key role of groups in shaping MFs enables reconstruction of a given survey’s SMF or BMF based on its group halo mass distribution.

  18. Excess production of low-mass lepton pairs in S+Au collisions at the CERN Super Proton Synchrotron and the quark-hadron phase transition

    SciTech Connect

    Srivastava, D.K.

    1996-02-01

    The mass distribution for excess dielectrons in S+Au collisions at 200{ital A} GeV measured by the CERES Collaboration at the CERN Super Proton Synchrotron is analyzed. The data are seen to be in satisfactory agreement with a scenario where a thermalized quark-gluon plasma is formed initially, which expands, cools, hadronizes, and undergoes a freeze-out. The same treatment is also seen to provide a reasonable description for the excess dimuons measured by the HELIOS/3 experiment for S+W collisions. {copyright} {ital 1996 The American Physical Society.}

  19. Measurement of the top-quark mass in the tt¯ dilepton channel using the full CDF Run II data set

    SciTech Connect

    Aaltonen, T.

    2015-08-06

    We present a measurement of the top-quark mass in events containing two leptons (electrons or muons) with a large transverse momentum, two or more energetic jets, and a transverse-momentum imbalance. We use the full proton-antiproton collision data set collected by the CDF experiment during the Fermilab Tevatron Run II at center-of-mass energy √s = 1.96 TeV, corresponding to an integrated luminosity of 9.1 fb–1. A special observable is exploited for an optimal reduction of the dominant systematic uncertainty, associated with the knowledge of the absolute energy of the hadronic jets. The distribution of this observable in the selected events is compared to simulated distributions of tt¯ dilepton signal and background. We measure a value for the top-quark mass of 171.5±1.9 (stat)±2.5 (syst) GeV/c2.

  20. Nucleon quark distributions in a covariant quark-diquark model

    SciTech Connect

    Ian Cloet; W. Bentz; Anthony Thomas

    2005-04-01

    Spin-dependent and spin-independent quark light-cone momentum distributions and structure functions are calculated for the nucleon. We utilize a modified Nambu-Jona-Lasinio model in which confinement is simulated by eliminating unphysical thresholds for nucleon decay into quarks. The nucleon bound state is obtained by solving the Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquarks channels are included. We find excellent agreement between our model results and empirical data.

  1. Hidden GeV-scale interactions of quarks.

    PubMed

    Dobrescu, Bogdan A; Frugiuele, Claudia

    2014-08-01

    We explore quark interactions mediated by new gauge bosons of masses in the 0.3-50 GeV range. A tight upper limit on the gauge coupling of light Z(') bosons is imposed by the anomaly cancellation conditions in conjunction with collider bounds on new charged fermions. Limits from quarkonium decays are model dependent, while electroweak constraints are mild. We derive the limits for a Z(') boson coupled to baryon number and then construct a Z(') model with relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a few GeV. PMID:25148315

  2. Hidden GeV-Scale Interactions of Quarks

    SciTech Connect

    Dobrescu, Bogdan A.; Frugiuele, Claudia

    2014-08-05

    We explore quark interactions mediated by new gauge bosons of masses in the 0.3 – 50 GeV range. A tight upper limit on the gauge coupling of light Z' bosons is imposed by the anomaly cancellation conditions in conjunction with collider bounds on new charged fermions. Limits from quarkonium decays are model dependent, while electroweak constraints are mild. We derive the limits for a Z' boson coupled to baryon number, and then construct a Z' model with relaxed constraints, allowing quark couplings as large as 0.2 for a mass of a few GeV.

  3. Hausdorff dimension of quark trajectories from SCSB and confinement

    SciTech Connect

    Antonov, D.; Ribeiro, J. E. F. T.

    2011-05-23

    The quark condensate is calculated using the effective-action formalism, by imposing an ansatz for the Wilson loop, which interpolates between the area-law for large loops and the area-squared law for small loops. For 3 colors and 2 light flavors, a lower bound of 460 MeV for the constituent quark mass is found to be accessible, provided an effective scale-dependent string tension of a light quark falls off linearly with the Schwinger proper time. This behavior of the effective string tension yields the Hausdorff dimension of a light-quark trajectory equal to 4, which shows that these trajectories are similar to branched polymers. A gluonic chain based on such trajectories provides an example of a model describing weak first-order deconfinement phase transition, which takes place in SU(3) Yang-Mills theory.

  4. Progress in Top Quark Physics

    SciTech Connect

    Thomson, Evelyn J.

    2006-07-11

    Experimental measurements of the properties of the top quark have improved and will continue to improve significantly, with the excellent operation of the CDF and D0 experiments and the Tevatron pp-bar collider at the Fermi National Accelerator Laboratory. All of the final state experimental signatures from top quark production and decay are being analysed to test if this most massive quark is sensitive to new physics beyond the standard model. So far, observations are consistent with the standard model. New techniques have dramatically improved the precision of the top quark mass measurement to 1.7% and set the stage for a sub-1% measurement by 2008. This improved knowledge of the top quark mass sharpens the standard model prediction for the mass of the undiscovered Higgs boson, with implications for Higgs studies at the future LHC and ILC.

  5. Progress in top quark physics

    SciTech Connect

    Thomson, Evelyn J.; /Pennsylvania U.

    2006-02-01

    Experimental measurements of the properties of the top quark have improved and will continue to improve significantly, with the excellent operation of the CDF and D0 experiments and the Tevatron p{bar p} collider at the Fermi National Accelerator Laboratory. All of the final state experimental signatures from top quark production and decay are being analyzed to test if this most massive quark is sensitive to new physics beyond the standard model. So far, observations are consistent with the standard model. New techniques have dramatically improved the precision of the top quark mass measurement to 1.7% and set the stage for a sub-1% measurement by 2008. This improved knowledge of the top quark mass sharpens the standard model prediction for the mass of the undiscovered Higgs boson, with implications for Higgs studies at the future LHC and ILC.

  6. Strange Quark Matter Status and Prospects

    NASA Technical Reports Server (NTRS)

    Sandweiss, J.

    2004-01-01

    The existence of quark states with more than three quarks is allowed in QCD. The stability of such quark matter states has been studied with lattice QCD and phenomenological bag models, but is not well constrained by theory. The addition of strange quarks to the system allows the quarks to be in lower energy states despite the additional mass penalty. There is additional stability from reduced Coulomb repulsion. SQM is expected to have a low Z/A. Stable or metastable massive multiquark states contain u, d, and s quarks.

  7. Rare Down Quark Decays

    NASA Astrophysics Data System (ADS)

    Tung, Kwong-Kwai Humphrey

    1992-01-01

    The rare decays bto sX are sensitive to strong interaction corrections. The effects can be estimated by a renormalization group technique which requires the evaluation of QCD mixing among effective operators. In the dimensional reduction and the naive dimensional regularization methods, there are discrepancies in evaluating the QCD mixing of the four-quark operators with the bto sgamma and bto s+gluon dipole operators. In this thesis, the problem is investigated by considering the contributions of the epsilon -scalar field and the epsilon -dimensional operators that distinguish between the two methods. The discrepancies are shown to come from the epsilon-dimensional four-quark operators in dimensional reduction and not from the epsilon -scalar field. In the decay bto sl^+l^ -, the intermediate of cc pairs in the charm-penguin diagram can form the resonance states J/psi and psi^'. In the published literature, there is a sign discrepancy in the Breit-Wigner amplitude for the resonance effects. Here, the sign difference is settled by considering the unitarity limit of the amplitude in the Argand diagram. The effects of the resonances are quite substantial on the invariant mass spectrum for this decay. However, they are shown to be negligible on the dilepton energy spectrum below 0.95 GeV. The energy spectrum is, thus, more useful than the invariant mass spectrum for measurements of the top -quark mass. The decays Bto K^*X are well modeled by the quark-level decays bto sX. In the quark model, the hadronization is done using a nonrelativistic wave function. In the decay B to K^*gamma, the large K ^* recoil creates an uncertainty in calculating the branching ratio using the quark model. The problem is explored by considering other meson processes where data exist. The data on the pi form factor and the omegapi^0 transition form factor suggest the necessity to retain relativistic spinor and meson normalizations in the quark -model; however, the data do not resolve the

  8. Data dependent systems methodology for lumped mass modeling of structures

    NASA Technical Reports Server (NTRS)

    Pandit, Sudhakar M.

    1988-01-01

    Limitations of the frequency domain methods in analyzing structura1 vibrations has created an awareness of the comparative merits of the time domain methods. Although time domain methods would be ideal for modeling large precisions space systems, the popular methods based on fitting theoretical response to actual data by least squares are too sensitive to noise and require too much data to be suitable for orbiting space crafts. This paper briefly reviews the theory and illustrative applications of a time domain methodology called Data Dependent Systems (DDS) that eliminates these limitations. Simulation results are presented to demonstrate a better than 4-place accuracy in the identifications of all system parameters, both modal (frequencies, damping ratios, and mode shapes) and physical (mass, stiffness, and damping matrices).

  9. Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State

    SciTech Connect

    Schieferdecker, Philipp; /Munich U.

    2005-08-01

    The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb{sup -1} of D0 Run II data, the mass of the top quark is measured to be: m{sub top}{sup {ell}+jets} = 169.5 {+-} 4.4(stat. + JES){sub -1.6}{sup +1.7}(syst.) GeV; m{sub top}{sup e+jets} = 168.8 {+-} 6.0(stat. + JES){sub -1.9}{sup +1.9}(syst.) GeV; m{sub top}{sup {mu}+jets} = 172.3 {+-} 9.6(stat.+JES){sub -3.3}{sup +3.4}(syst.) GeV. The jet energy scale measurement in the {ell}+jets sample yields JES = 1.034 {+-} 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

  10. Reporting and measurement of mass-dependent and mass-independent fractionation of mercury isotopes

    NASA Astrophysics Data System (ADS)

    Bergquist, B. A.; Blum, J. D.

    2007-12-01

    Hg isotope analysis by MC-ICP-MS is an important new approach for fingerprinting Hg sources and monitoring Hg redox reactions and bioaccumulation, especially with the recent discovery of mass independent Hg isotope fractionation. Unfortunately research groups have adopted different standards, definitions of delta values, and methods of isotopic measurement. We suggest that a single standard, NIST SRM 3133, be adopted for reporting the isotopic variability of Hg isotopes. Isotope ratios should be determined by sample-standard bracketing (SSB) during analysis and reported as permil (‰) deviation from SRM 3133. For the highest precision and accuracy, a Tl internal standard along with SSB should be used to correct instrumental mass bias. Measurement routines should also include on-peak zero corrections and matching of concentration and matrix between the samples and bracketing standard. For samples that display mass-dependent fractionation (MDF), only one delta value needs to be reported (δ202/198Hg). Mass-independent fractionation (MIF) (Jackson et al., 2006; Bergquist et al., 2006; Bergquist and Blum, submitted) requires additional nomenclature, and we suggest reporting MIF as the deviation in isotope ratios from the theoretical mass dependent kinetic isotope fractionation (Δxxx/198Hg)¬. External reproducibility should be monitored by analysis of secondary standards. For studies of MDF, we use an in-house secondary standard solution made from metallic Hg mined from Almaden Spain and obtain a δ202Hg of -0.55 ±0.06‰ (2SD). For studies of MIF, we use NRCC CRM DORM-2 (dogfish muscle) and obtain a mean value of δ202Hg of +0.19 ±0.13‰ (2SD), Δ201Hg of +0.89 ±0.07‰ (2SD) , and Δ199Hg of +1.07 ±0.08‰ (2SD).

  11. A Measurement of the Top Quark Mass in 1.96 TeV Proton-Antiproton Collisions Using a Novel Matrix Element Method

    SciTech Connect

    Freeman, John

    2007-01-01

    A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix element techniques, the method involves an integration using the Standard Model matrix element for t$\\bar{t}$ production and decay. However, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb-1 data sample, using events with a high-pT lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find Mmeas = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c2.

  12. Search for Scalar Bottom Quarks from Gluino Decays in Proton - Anti-proton Collisions at a Center-of-Mass Energy of 1.96-TeV

    SciTech Connect

    Rott, Carsten

    2004-12-01

    The authors have performed a search for the scalar bottom quark ({tilde b}{sub 1}) from gluino ({tilde g}) decays in an R-parity conserving SUSY scenario with m{sub {tilde g}} > m{sub {tilde b}{sub 1}}, by investigating a final state of large missing transverse energy, with three or more jets, and some of them from the hadronization of b-quarks. A data sample of 156 pb{sup -1} collected by the Collider Detector at Fermilab at a center-of-mass energy of {radical}s = 1.96 TeV was used. For the final selection, jets containing secondary displaced vertices were required. This analysis has been performed ''blind'', in that the inspection of the signal region was only made after the Standard Model prediction was finalized. Comparing data with SUSY predictions, they can exclude masses of the gluino and sbottom of up to 280 and 240 GeV/c{sup 2} respectively.

  13. A measurement of the top quark mass in 1.96 TeV proton-antiproton collisions using a novel matrix element method

    SciTech Connect

    Freeman, John C

    2007-01-01

    A measurement of the top quark mass in t$\\bar{t}$ → l + jets candidate events, obtained from p$\\bar{p}$ collisions at √s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncertainty of the jet momentum reconstruction. As with all matrix elements techniques, the method involves an integration using the Standard Model matrix element for tt production and decay. however, the technique presented is unique in that the matrix element is modified to compensate for kinematic assumptions which are made to reduce computation time. Background events are dealt with through use of an event observable which distinguishes signal from background, as well as through a cut on the value of an event's maximum likelihood. Results are based on a 955 pb-1 data sample, using events with a high-pT lepton and exactly four high-energy jets, at least one of which is tagged as coming from a b quark; 149 events pass all the selection requirements. They find Mmeas = 169.8 ± 2.3(stat.) ± 1.4(syst.) GeV/c2.

  14. Position-dependent mass quantum Hamiltonians: general approach and duality

    NASA Astrophysics Data System (ADS)

    Rego-Monteiro, M. A.; Rodrigues, Ligia M. C. S.; Curado, E. M. F.

    2016-03-01

    We analyze a general family of position-dependent mass (PDM) quantum Hamiltonians which are not self-adjoint and include, as particular cases, some Hamiltonians obtained in phenomenological approaches to condensed matter physics. We build a general family of self-adjoint Hamiltonians which are quantum mechanically equivalent to the non-self-adjoint proposed ones. Inspired by the probability density of the problem, we construct an ansatz for the solutions of the family of self-adjoint Hamiltonians. We use this ansatz to map the solutions of the time independent Schrödinger equations generated by the non-self-adjoint Hamiltonians into the Hilbert space of the solutions of the respective dual self-adjoint Hamiltonians. This mapping depends on both the PDM and on a function of position satisfying a condition that assures the existence of a consistent continuity equation. We identify the non-self-adjoint Hamiltonians here studied with a very general family of Hamiltonians proposed in a seminal article of Harrison (1961 Phys. Rev. 123 85) to describe varying band structures in different types of metals. Therefore, we have self-adjoint Hamiltonians that correspond to the non-self-adjoint ones found in Harrison’s article.

  15. Top quark production at the Tevatron

    SciTech Connect

    Varnes, Erich W.; /Arizona U.

    2010-09-01

    The Fermilab Tevatron has, until recently, been the only accelerator with sufficient energy to produce top quarks. The CDF and D0 experiments have collected large samples of top quarks. We report on recent top quark production measurements of the single top and t{bar t} production cross sections, as well as studies of the t{bar t} invariant mass distribution and a search for highly boosted top quarks.

  16. Secondary production of massive quarks in thrust

    NASA Astrophysics Data System (ADS)

    Hoang, André H.; Mateu, Vicent; Pietrulewicz, Piotr

    2016-01-01

    We present a factorization framework that takes into account the production of heavy quarks through gluon splitting in the thrust distribution for e+e- → hadrons. The explicit factorization theorems and some numerical results are displayed in the dijet region where the kinematic scales are widely separated, which can be extended systematically to the whole spectrum. We account for the necessary two-loop matrix elements, threshold corrections, and include resummation up to N3LL order. We include nonperturbative power corrections through a field theoretical shape function, and remove the O(ΛQCD) renormalon in the partonic soft function by appropriate mass-dependent subtractions. Our results hold for any value of the quark mass, from an infinitesimally small (merging to the known massless result) to an infinitely large one (achieving the decoupling limit). This is the first example of an application of a variable flavor number scheme to final state jets.

  17. Search for mirror quarks at the LHC

    NASA Astrophysics Data System (ADS)

    Chakdar, Shreyashi; Ghosh, K.; Hoang, V.; Hung, P. Q.; Nandi, S.

    2016-02-01

    Observation of nonzero neutrino masses at a scale ˜1 0-1- 1 0-2 eV is a major problem in the otherwise highly successful Standard Model. The most elegant mechanism to explain such tiny neutrino masses is the seesaw mechanism with right-handed neutrinos. However, the required seesaw scale is so high, ˜1014 GeV , it will not have any collider implications. Recently, an explicit model has been constructed to realize the seesaw mechanism with the right-handed neutrinos at the electroweak scale. The model has a mirror symmetry, having both the left and right lepton and quark doublets and singlets for the same S U (2 )W gauge symmetry. Additional Higgs multiplets have been introduced to realize this scenario. It turns out that these extra Higgs fields also help to satisfy the precision electroweak tests, and other observables. Because the scale of the symmetry breaking is electroweak, both the mirror quark and the mirror leptons have masses in the electroweak scale in the range ˜150 - 800 GeV . The mirror quarks/leptons decay to ordinary quarks/leptons plus very light neutral scalars. In this work, we calculate the final-state signals arising from the pair productions of these mirror quarks and their subsequent decays. We find that these signals are well observable over the Standard Model background for the 13 TeV LHC. Depending on the associated Yukawa couplings, these decays can also give rise to displaced vertices with long decay lengths, very different from the usual displaced vertices associated with b decays.

  18. Valence quark spin distribution functions

    SciTech Connect

    Nathan Isgur

    1998-09-01

    The hyperfine interactions of the constituent quark model provide a natural explanation for many nucleon properties, including the {Delta} - N splitting, the charge radius of the neutron, and the observation that the proton's quark distribution function ratio d(x)/u(x) {r_arrow} 0 as x {r_arrow} 1. The hyperfine-perturbed quark model also makes predictions for the nucleon spin-dependent distribution functions. Precision measurements of the resulting asymmetries A{sub 1}{sup p}(x) and A{sub 1}{sup n}(x) in the valence region can test this model and thereby the hypothesis that the valence quark spin distributions are ''normal''.

  19. How Lyman Alpha Emission Depends on Galaxy Stellar Mass

    NASA Astrophysics Data System (ADS)

    Oyarzún, Grecco A.; Blanc, Guillermo A.; González, Valentino; Mateo, Mario; Bailey, John I., III; Finkelstein, Steven L.; Lira, Paulina; Crane, Jeffrey D.; Olszewski, Edward W.

    2016-04-01

    In this work, we show how the stellar mass (M *) of galaxies affects the 3 < z < 4.6 Lyα equivalent width (EW) distribution. To this end, we design a sample of 629 galaxies in the M * range 7.6\\lt {log}{M}*/{M}ȯ \\lt 10.6 from the 3D-HST/CANDELS survey. We perform spectroscopic observations of this sample using the Michigan/Magellan Fiber System, allowing us to measure Lyα fluxes and use 3D-HST/CANDELS ancillary data. In order to study the Lyα EW distribution dependence on M *, we split the whole sample in three stellar mass bins. We find that, in all bins, the distribution is best represented by an exponential profile of the form {dN}({M}*)/d{EW}={W}0{({M}*)}-1A({M}*){e}-{EW/{W}0({M}*)}. Through a Bayesian analysis, we confirm that lower M * galaxies have higher Lyα EWs. We also find that the fraction A of galaxies featuring emission and the e-folding scale W 0 of the distribution anti-correlate with M *, recovering expressions of the forms A({M}*)=-0.26(.13){log}{M}*/{M}ȯ +3.01(1.2) and {W}0({M}*)=-15.6(3.5){log}{M}*/{M}ȯ +166(34). These results are crucial for proper interpretation of Lyα emission trends reported in the literature that may be affected by strong M * selection biases.

  20. Atomic mass dependent electrostatic diagnostics of colliding laser plasma plumes

    SciTech Connect

    Yeates, P.; Fallon, C.; Kennedy, E. T.; Costello, J. T.; School of Physical Sciences, Dublin City University , Dublin 7

    2013-09-15

    The behaviours of colliding laser plasma plumes (C{sub p}) compared with single plasma plumes (S{sub p}) are investigated for 14 different atomic mass targets. A Faraday cup, situated at the end of a drift tube (L = 0.99 m), is employed to record the time-of-flight (TOF) current traces for all elements and both plume configurations, for a fixed laser intensity of I{sub p} = 4.2 × 10{sup 10} W cm{sup −2} (F = 0.25 kJ cm{sup −2}). The ratio of the peak current from the C{sub p} relative to twice that from the S{sub p} is designated as the peak current ratio while the ratio of the integrated charge yield from the C{sub p} relative to twice that from the S{sub p} is designated as the charge yield ratio. Variation of the position of the Faraday cup within the drift tube (L = 0.33, 0.55, and 0.99 m) in conjunction with a lower laser fluence (F = 0.14 kJ cm{sup −2}) facilitated direct comparison of the changing TOF traces from both plasma configurations for the five lightest elements studied (C, Al, Si, Ti, and Mn). The results are discussed in the frame of laser plasma hydrodynamic modelling to approximate the critical recombination distance L{sub CR}. The dynamics of colliding laser plasma plumes and the atomic mass dependence trends observed are presented and discussed.

  1. Quark number fluctuations at high temperatures

    SciTech Connect

    Petreczky, P.; Hegde, P.; Velytsky, A.

    2009-11-01

    We calculate the second, fourth and sixth order quark number fluctuations in the deconfined phase of 2+1 flavor QCD using lattices with temporal extent N{sub t} = 4,6,8 and 12. We consider light, strange and charm quarks. We use p4 action for valence quarks and gauge configurations generated with p4 action with physical value of the strange quark mass and light quark mass m{sub q} = 0.1 m{sub s} generated by the RBC-Bielefeld collaboration. We observe that for all quark masses the quark number fluctuations rapidly get close to the corresponding ideal gas limits. We compare our results to predictions of a quasi-particle model and resummed high temperature perturbative calculations. We also investigate correlations among different flavor channels.

  2. Microbial mass-dependent fractionation of chromium isotopes

    USGS Publications Warehouse

    Sikora, E.R.; Johnson, T.M.; Bullen, T.D.

    2008-01-01

    Mass-dependent fractionation of Cr isotopes occurs during dissimilatory Cr(VI) reduction by Shewanella oneidensis strain MR-1. Cells suspended in a simple buffer solution, with various concentrations of lactate or formate added as electron donor, reduced 5 or 10 ??M Cr(VI) to Cr(III) over days to weeks. In all nine batch experiments, 53Cr/52Cr ratios of the unreacted Cr(VI) increased as reduction proceeded. In eight experiments covering a range of added donor concentrations up to 100 ??M, isotopic fractionation factors were nearly invariant, ranging from 1.0040 to 1.0045, with a mean value somewhat larger than that previously reported for abiotic Cr(VI) reduction (1.0034). One experiment containing much greater donor concentration (10 mM lactate) reduced Cr(VI) much faster and exhibited a lesser fractionation factor (1.0018). These results indicate that 53Cr/52Cr measurements should be effective as indicators of Cr(VI) reduction, either bacterial or abiotic. However, variability in the fractionation factor is poorly constrained and should be studied for a variety of microbial and abiotic reduction pathways. ?? 2008 Elsevier Ltd.

  3. Position-dependent mass, finite-gap systems, and supersymmetry

    NASA Astrophysics Data System (ADS)

    Bravo, Rafael; Plyushchay, Mikhail S.

    2016-05-01

    The ordering problem in quantum systems with position-dependent mass (PDM) is treated by inclusion of the classically fictitious similarity transformation into the kinetic term. This provides a generation of supersymmetry with the first-order supercharges from the kinetic term alone, while inclusion of the potential term allows us also to generate nonlinear supersymmetry with higher-order supercharges. A broad class of finite-gap systems with PDM is obtained by different reduction procedures, and general results on supersymmetry generation are applied to them. We show that elliptic finite-gap systems of Lamé and Darboux-Treibich-Verdier types can be obtained by reduction to Seiffert's spherical spiral and Bernoulli lemniscate in the presence of Calogero-like or harmonic oscillator potentials, or by angular momentum reduction of a free motion on some AdS2 -related surfaces in the presence of Aharonov-Bohm flux. The limiting cases include the Higgs and Mathews-Lakshmanan oscillator models as well as a reflectionless model with PDM exploited recently in the discussion of cosmological inflationary scenarios.

  4. Quantifying zigzag motion of quarks

    SciTech Connect

    Antonov, D.; Ribeiro, J. E. F. T.

    2010-03-01

    The quark condensate is calculated in terms of the effective string tension and the constituent quark mass. For 3 colors and 2 light flavors, the constituent mass is bounded from below by the value of 460 MeV. This value is only accessible when the string tension decreases linearly with the Schwinger proper time. For this reason, the Hausdorff dimension of a light-quark trajectory is equal to 4, indicating that these trajectories are similar to branched polymers, which can describe a weak first-order deconfinement phase transition in SU(3) Yang-Mills theory. Using this indication, we develop a gluon-chain model based on such trajectories.

  5. QUARK-NOVAE IN LOW-MASS X-RAY BINARIES. II. APPLICATION TO G87-7 AND TO GRB 110328A

    SciTech Connect

    Ouyed, Rachid; Staff, Jan; Jaikumar, Prashanth

    2011-12-20

    We propose a simple model explaining two outstanding astrophysical problems related to compact objects: (1) that of stars such as G87-7 (alias EG 50) that constitute a class of relatively low-mass white dwarfs (WDs) which nevertheless fall away from the C/O composition and (2) that of GRB 110328A/Swift J164449.3+57345 which showed spectacularly long-lived strong X-ray flaring, posing a challenge to standard gamma-ray burst models. We argue that both these observations may have an explanation within the unified framework of a quark-nova (QN) occurring in a low-mass X-ray binary (LMXB; neutron star (NS)-WD). For LMXBs, where the binary separation is sufficiently tight, ejecta from the exploding NS triggers nuclear burning in the WD on impact, possibly leading to Fe-rich composition compact WDs with mass 0.43 M{sub Sun} < M{sub WD} < 0.72 M{sub Sun }, reminiscent of G87-7. Our results rely on the assumption, which ultimately needs to be tested by hydrodynamic and nucleosynthesis simulations, that under certain circumstances the WD can avoid the thermonuclear runaway. For heavier WDs (i.e., M{sub WD} > 0.72 M{sub Sun }) experiencing the QN shock, degeneracy will not be lifted when carbon burning begins, and a sub-Chandrasekhar Type Ia supernova may result in our model. Under slightly different conditions and for pure He WDs (i.e., M{sub WD} < 0.43 M{sub Sun }), the WD is ablated and its ashes raining down on the quark star (QS) leads to accretion-driven X-ray luminosity with energetics and duration reminiscent of GRB 110328A. We predict additional flaring activity toward the end of the accretion phase if the QS turns into a black hole.

  6. Transverse momentum dependence of the quark helicity distributions and the Cahn effect in double-spin asymmetry A{sub LL} in semiinclusive DIS

    SciTech Connect

    Anselmino, M.; Efremov, A.; Kotzinian, A.; Parsamyan, B.

    2006-10-01

    Within the LO QCD parton model of Semi-Inclusive Deep Inelastic Scattering, lN{yields}lhX, with unintegrated quark distribution and fragmentation functions, we study the P{sub hT} dependence of the double longitudinal-spin asymmetry A{sub LL}. We include 1/Q kinematic corrections, which induce an azimuthal modulation of the asymmetry, analogous to the Cahn effect in unpolarized SIDIS. We show that a study of A{sub LL} and of the weighted DSA A{sub LL}{sup cos{phi}{sub h}} allows to extract the transverse momentum dependence of the unintegrated helicity distribution function g{sub 1L}{sup q}(x,k{sub perpendicular}) [or {delta}q(x,k{sub perpendicular})]. Predictions, based on some models for the unknown functions, are given for ongoing COMPASS, HERMES and JLab experiments.

  7. Light-quark two-loop corrections to heavy-quark pair production in the gluon fusion channel

    NASA Astrophysics Data System (ADS)

    Bonciani, R.; Ferroglia, A.; Gehrmann, T.; von Manteuffel, A.; Studerus, C.

    2013-12-01

    We calculate the two-loop corrections to heavy-quark pair production in the gluon fusion channel which arise from diagrams involving a closed light-quark loop. The calculation is carried out by keeping the exact dependence on the heavy-quark mass. The analytic results are written in terms of logarithms, classical polylogarithms Li n ( n = 2 , 3 , 4), and genuine multiple polylogarithms Li2,2. The functional arguments are rational expressions of two independent external invariants and they are chosen in such a way that the functions are real in all the physical phase-space points. Through systematic changes in the functional basis, we obtain expansions of the results in both the production threshold and small mass limits.

  8. Precision Measurement of the Neutron Spin Asymmetries and Spin-dependent Structure Functions in the Valence Quark Region

    SciTech Connect

    Xiaochao Zheng; Konrad Aniol; David Armstrong; Todd Averett; William Bertozzi; Sebastien Binet; Etienne Burtin; Emmanuel Busato; Cornel Butuceanu; John Calarco; Alexandre Camsonne; Gordon Cates; Zhengwei Chai; Jian-ping Chen; Seonho Choi; Eugene Chudakov; Francesco Cusanno; Raffaele De Leo; Alexandre Deur; Sonja Dieterich; Dipangkar Dutta; John Finn; Salvatore Frullani; Haiyan Gao; Juncai Gao; Franco Garibaldi; Shalev Gilad; Ronald Gilman; Javier Gomez; Jens-ole Hansen; Douglas Higinbotham; Wendy Hinton; Tanja Horn; Cornelis De Jager; Xiaodong Jiang; Lisa Kaufman; James Kelly; Wolfgang Korsch; Kevin Kramer; John Lerose; David Lhuillier; Nilanga Liyanage; Demetrius Margaziotis; Frederic Marie; Pete Markowitz; Kathy Mccormick; Zein-eddine Meziani; Robert Michaels; Bryan Moffit; Sirish Nanda; Damien Neyret; Sarah Phillips; Anthony Powell; Thierry Pussieux; Bodo Reitz; Julie Roche; Michael Roedelbronn; Guy Ron; Marat Rvachev; Arunava Saha; Nikolai Savvinov; Jaideep Singh; Simon Sirca; Karl Slifer; Patricia Solvignon; Paul Souder; Daniel Steiner; Steffen Strauch; Vincent Sulkosky; William Tobias; Guido Urciuoli; Antonin Vacheret; Bogdan Wojtsekhowski; Hong Xiang; Yuan Xiao; Feng Xiong; Bin Zhang; Lingyan Zhu; Xiaofeng Zhu; Piotr Zolnierczuk

    2004-05-01

    We report on measurements of the neutron spin asymmetries A{sub 1,2}{sup n} and polarized structure functions g{sub 1,2}{sup n} at three kinematics in the deep inelastic region, with x = 0.33, 0.47 and .60 and Q{sub 2} = 2.7, 3.5 and 4.8 (GeV/c){sup 2}, respectively. These measurements were performed using a 5.7 GeV longitudinally-polarized electron beam and a polarized {sup 3}He target. The results for A{sub 1}{sup n} and g{sub 1}{sup n} at x = 0.33 are consistent with previous world data and, at the two higher x points, have improved the precision of the world data by about an order of magnitude. The new A{sub 1}{sup n} data show a zero crossing around x = 0.47 and the value at x = 0.60 is significantly positive. These results agree with a next-to-leading order QCD analysis of previous world data. The trend of data at high x agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (pQCD) assuming hadron helicity conservation. Results for A{sub 2}{sup n} and g{sub 2}{sup n} have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment d{sub 2}{sup n} was evaluated and the new result has improved the precision of this quantity by about a factor of two. When combined with the world proton data, polarized quark distribution functions were extracted from the new g{sub 1}{sup n}/F{sub 1}{sup n} values based on the quark parton model. While results for {Delta}u/u agree well with predictions from various models, results for {Delta}d/d disagree with the leading-order pQCD prediction when hadron helicity conservation is imposed.

  9. Precision measurement of the neutron spin asymmetries and spin-dependent structure functions in the valence quark region

    SciTech Connect

    Zheng, X.; Bertozzi, W.; Chai, Z.; Dutta, D.; Gao, H.; Gilad, S.; Higinbotham, D.W.; Rvachev, M.; Sirca, S.; Xiang, H.; Xiao, Y.; Xiong, F.; Zhang, B.; Zhu, L.; Aniol, K.; Margaziotis, D.J.; Armstrong, D.S.; Butuceanu, C.; Finn, J.M.; Kramer, K.

    2004-12-01

    We report on measurements of the neutron spin asymmetries A{sub 1,2}{sup n} and polarized structure functions g{sub 1,2}{sup n} at three kinematics in the deep inelastic region, with x=0.33, 0.47, and 0.60 and Q{sup 2}=2.7, 3.5, and 4.8 (GeV/c){sup 2}, respectively. These measurements were performed using a 5.7 GeV longitudinally polarized electron beam and a polarized {sup 3}He target. The results for A{sub 1}{sup n} and g{sub 1}{sup n} at x=0.33 are consistent with previous world data and, at the two higher-x points, have improved the precision of the world data by about an order of magnitude. The new A{sub 1}{sup n} data show a zero crossing around x=0.47 and the value at x=0.60 is significantly positive. These results agree with a next-to-leading-order QCD analysis of previous world data. The trend of data at high x agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (PQCD) assuming hadron helicity conservation. Results for A{sub 2}{sup n} and g{sub 2}{sup n} have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment d{sub 2}{sup n} was evaluated and the new result has improved the precision of this quantity by about a factor of 2. When combined with the world proton data, polarized quark distribution functions were extracted from the new g{sub 1}{sup n}/F{sub 1}{sup n} values based on the quark-parton model. While results for {delta}u/u agree well with predictions from various models, results for {delta}d/d disagree with the leading-order PQCD prediction when hadron helicity conservation is imposed.

  10. Detecting heavy quarks

    SciTech Connect

    Benenson, G.; Chau, L.L.; Ludlam, T.; Paige, F.E.; Platner, E.D.; Protopopescu, S.D.; Rehak, P.

    1983-01-01

    In this exercise we examine the performance of a detector specifically configured to tag heavy quark (HQ) jets through direct observations of D-meson decays with a high resolution vertex detector. To optimize the performance of such a detector, we assume the small diamond beam crossing configuration as described in the 1978 ISABELLE proposal, giving a luminosity of 10/sup 32/ cm/sup -2/ sec/sup -1/. Because of the very large backgrounds from light quark (LQ) jets, most triggering schemes at this luminosity require high P/sub perpendicular to/ leptons and inevitably give missing neutrinos. If alternative triggering schemes could be found, then one can hope to find and calculate the mass of objects decaying to heavy quarks. A scheme using the high resolution detector will also be discussed in detail. The study was carried out with events generated by the ISAJET Monte Carlo and a computer simulation of the described detector system. (WHK)

  11. Measurement of the t t-bar production cross section and the top quark mass in the dilepton channel in pp collisions at sqrt(s) =7 TeV

    SciTech Connect

    Chatrchyan, Serguei; Khachatryan, Vardan; Sirunyan, Albert M.; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Ero, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; /Yerevan Phys. Inst. /Vienna, OAW /Minsk, High Energy Phys. Ctr. /Antwerp U., WISINF /Vrije U., Brussels /Brussels U. /Gent U. /Louvain U. /UMH, Mons /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Yerevan Phys. Inst. /Vienna, OAW /Minsk, High Energy Phys. Ctr. /Antwerp U., WISINF /Vrije U., Brussels /Brussels U. /Gent U. /Louvain U. /UMH, Mons /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Yerevan Phys. Inst. /Vienna, OAW /Minsk, High Energy Phys. Ctr. /Antwerp U., WISINF /Vrije U., Brussels /Brussels U. /Gent U. /Louvain U. /UMH, Mons /Rio de Janeiro, CBPF /Rio de Janeiro State U.

    2011-05-01

    The t{bar t} production cross section and top quark mass are measured in proton-proton collisions at {radical}s = 7 TeV in a data sample corresponding to an integrated luminosity of 36 pb{sup -1} collected by the CMS experiment. The measurements are performed in events with two leptons (electrons or muons) in the final state. Results of the cross section measurement in events with and without b-quark identification are obtained and combined. The measured value is {sigma}{sub t{bar t}} = 168 {+-} 18 (stat.) {+-} 14 (syst.) {+-} 7 (lumi.) pb, consistent with predictions from the standard model. The top quark mass m{sub top} is reconstructed with two different methods, a full kinematic analysis and a matrix weighting technique. The combination yields a measurement of m{sub top} = 175.5 {+-} 4.6 (stat.) {+-} 4.6 (syst.) GeV/c{sup 2}.

  12. Forward-Backward Asymmetry at High Mass in Top Quark Pair Production in Proton-Antiproton Collisions at Center of Mass Energy = 1.96 TeV

    NASA Astrophysics Data System (ADS)

    Eppig, Andrew Peter

    We present a new measurement of the inclusive forward-backward tt¯ production asymmetry and its mass dependence. The measurements are performed with data corresponding to an integrated luminosity of L = 5.3 fb-1 of pp¯ collisions at s = 1.96 TeV, recorded with the CDF II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the tt¯ rest frame, and in both cases are found to be consistent with CP conservation under interchange of t and t¯. In the tt¯ rest frame, the asymmetry is observed to increase with the invariant mass, Mtt¯, of the tt¯ system. Fully corrected parton-level asymmetries are derived in two regions of Mtt¯, and the asymmetry is found to be most significant at large Mtt¯ . For Mtt¯ ≥ 450 GeV/ c2, the parton-level asymmetry in the tt¯ rest frame is Att¯ = 0.475 +/- 0.114 compared to a next-to-leading order QCD prediction of 0.088 +/- 0.013.

  13. Heavy quark production processes in QCD

    SciTech Connect

    Brodsky, S.J.; Gunion, J.F.

    1984-12-01

    We have identified two novel effects in QCD, each of which acts to enhance the production of heavy quark and supersymmetric particles beyond what is conventionally expected from gluon fusion. Both effects are present in QED, but are compounded in QCD because of the increased number of diagrams and the much larger coupling constant. The intrinsic charm quark distribution in the nucleon could account for the observed enhancements of the charm structure function at large x and features of the charm production data but this mechanism is relatively suppressed for heavier systems. Prebinding distortion of the fusion cross section is, however, likely to be significant for the production at low p/sub T/ of all particles containing heavy colored constituents. At this stage the QCD calculations are highly model dependent although they agree with the general properties which can be inferred from the operator product expansion in the heavy quark mass. Much more theoretical analysis of these effects is clearly needed. It is also clear that much more experimental work is necessary to extend and confirm the reported anomalous heavy quark signals. 22 references.

  14. Top quark mass determination on double b-tagged events in barpp Collsions at √s = 1.8 TeV

    NASA Astrophysics Data System (ADS)

    CDF Collaboration

    1996-05-01

    We report on the measurement of the top quark mass using complete kinematic reconstruction of events containing a W and 4 jets. Two of the jets are required to be identified as b-jets. Data were collected by the Collider Detector at Fermilab (CDF) in the barpp collisions at √s = 1.8 TeV. Results are reported for 110 pb-1 of integrated luminosity. We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation. Supported by the Ministry of Education, Science and Culture of Japan.

  15. Location Dependence of Mass Sensitivity for Acoustic Wave Devices

    PubMed Central

    Zhang, Kewei; Chai, Yuesheng; Cheng, Z.-Y.

    2015-01-01

    It is introduced that the mass sensitivity (Sm) of an acoustic wave (AW) device with a concentrated mass can be simply determined using its mode shape function: the Sm is proportional to the square of its mode shape. By using the Sm of an AW device with a uniform mass, which is known for almost all AW devices, the Sm of an AW device with a concentrated mass at different locations can be determined. The method is confirmed by numerical simulation for one type of AW device and the results from two other types of AW devices. PMID:26404313

  16. Phenomenology of heavy quark production

    SciTech Connect

    Berger, E.L.

    1989-01-01

    A review is presented of heavy quark production in {bar p}p, {pi}{sup -}p, and pp interactions at fixed target and collider energies. Calculations of total cross sections and of single quark inclusive differential cross sections d{sup 2}{omega}/dk{sub T}dy are described including contributions through next-to-leading order in QCD perturbation theory. Comparisons with available data on charm and bottom quark production show good agreement for reasonable values of the charm and bottom quark masses and other parameters. Predictions and open issues in the interpretation of results are summarized. A brief discussion is presented of signatures, backgrounds, and expected event rates for top quark production. 24 refs., 6 figs.

  17. The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory

    SciTech Connect

    Calle Cordon, Alvaro C.; DeGrand, Thomas A.; Goity, Jose L.

    2014-07-01

    Baryon masses at varying values of Nc and light quark masses are studied with Lattice QCD and the results are analyzed in a low energy effective theory based on a combined framework of the 1/Nc and Heavy Baryon Chiral Perturbation Theory expansions. Lattice QCD results for Nc=3, 5 and 7 obtained in quenched calculations, as well as results for unquenched calculations for Nc=3, are used for the analysis. The results are consistent with a previous analysis of Nc=3 LQCD results, and in addition permit the determination of sub-leading in 1/Nc effects in the spin-flavor singlet component of the baryon masses as well as in the hyperfine splittings.

  18. Measurement of the top quark mass with the dynamical likelihood method using lepton plus jets events with b-tags in pp collisions at {radical}(s)=1.96 TeV

    SciTech Connect

    Abulencia, A.; Budd, S.; Chu, P.H.; Ciobanu, C.I.; Errede, D.; Errede, S.; Gerberich, H.; Grundler, U.; Junk, T.R.; Kraus, J.; Liss, T.M.; Marino, C.; Pitts, K.; Rogers, E.; Taffard, A.; Veramendi, G.; Vickey, T.; Zhang, X.; Acosta, D.; Cruz, A.

    2006-05-01

    This paper describes a measurement of the top quark mass, M{sub top}, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/antitop (tt) pairs in pp collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb{sup -1}. We use the tt candidates in the 'lepton+jets' decay channel, requiring at least one jet identified as a b quark by finding a displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of M{sub top} per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 tt candidates observed in the data, with 9.2 events expected from background, we measure the top quark mass to be 173.2(+2.6/-2.4)(stat.){+-}3.2(syst.) GeV/c{sup 2}, or 173.2(+4.1/-4.0) GeV/c{sup 2}.

  19. Top quark physics at the LHC

    NASA Astrophysics Data System (ADS)

    Kim, Tae Jeong

    2014-04-01

    In 2011, an integrated luminosity of more than 5 fb-1 at 7 TeV has been delivered by the LHC. The measurement of the cross section in top quark pair production and in single top quark production, top quark mass, top quark properties and new physics searches in top quark decays have been performed at the CMS experiment with various integrated luminosities. An overview of the latest results of these measurements and searches by the time of ICFP 2012 conference will be presented.

  20. Synthesis of baryons from unconfined quarks

    SciTech Connect

    Dicus, D.A.; Pati, J.C.; Teplitz, V.L.

    1980-02-15

    We calculate, for a number of cases, the cosmic temperature at which primordial quarks condense into baryons, within a field theory of partially confined quarks that enjoys temporary asymptotic freedom. We assume that the mass of a quark in a dense quark-antiquark medium is a monotonic function of the medium: that is, we assume the validity of the so-called ''Archimedes effect.'' We show that, within such models, unbound-quark lifetimes are larger than the age of the universe at the time of the transition.

  1. Top Quark Studies at D0

    SciTech Connect

    Peters, Reinhild Yvonne

    2014-11-26

    Years after its discovery in 1995 by CDF and D0, the top quark still undergoes intense investigations at the Tevatron. Using up to the full Run II data sample, new measurements of top quark production and properties by the D0 Collaboration are presented. In particular, the first observation of single top quark s-channel production, the measurement of differential tbar t distributions, forward-backward tbar t asymmetry, a new measurement of the top quark mass, and a measurement of the top quark charge are discussed.

  2. Confining quark condensate model of the nucleon.

    SciTech Connect

    Frank, Michael; Tandy, Peter

    1992-07-01

    We obtain a mean-field solution for the nucleon as a quark-meson soliton obtained from the action of the global color-symmetry model of QCD. All dynamics is generated from an effective interaction of quark currents. At the quark-meson level there are two novel features: (1) absolute confinement is produced from the space-time structure of the dynamical self-energy in the vacuum quark propagator; and (2) the related scalar meson field is an extended q-barq composite that couples nonlocally to quarks. The influence of these features upon the nucleon mass contributions and other nucleon properties is presented.

  3. Measurements of top quark properties at CDF

    SciTech Connect

    Kraan, Aafke C.; /Pennsylvania U.

    2006-11-01

    The top quark with its mass of about 172 GeV/c{sup 2} is the most massive fundamental particle observed by experiment. In this talk they highlight the most recent measurements of several top quark properties performed with the CDF detector based on data samples corresponding to integrated luminosities up to 1 fb{sup -1}. These results include a search for top quark pair production via new massive resonances, measurements of the helicity of the W boson from top-quark decay, and a direct limit on the lifetime of the top quark.

  4. Measurement of the Double-inclusive b\\overlineb Quark Fragmentation Function in Z^0 decays and First Measurement of Angle Dependant B-\\overlineB Energy Correlations

    NASA Astrophysics Data System (ADS)

    Burrows, Philip

    2003-04-01

    We present preliminary results of a measurement of the double-inclusive b\\overlineb quark fragmentation function in Z^0 decays using a novel kinematic B hadron energy reconstruction technique. The measurement is performed using 350,000 hadronic Z^0 events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector are used to reconstruct topological B-decay vertices with high efficiency and purity, and to provide precise measurements of the kinematic quantities used in this technique. We measure the B energy with good efficiency and resolution over the full kinematic range. We present a preliminary measurement of the angle dependent correlations between the B and barB hadron energies in Z^0 arrow b\\overlineb events, and compare with the leading order QCD predictions.

  5. Landau levels of cold dense quark matter in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    Wen, Xin-Jian; Liang, Jun-Jun

    2016-07-01

    The occupied Landau levels of strange quark matter are investigated in the framework of the SU(3) NJL model with a conventional coupling and a magnetic-field dependent coupling respectively. At lower density, the Landau levels are mainly dominated by u and d quarks. Threshold values of the chemical potential for the s quark onset are shown in the μ -B plane. The magnetic-field-dependent running coupling can broaden the region of three-flavor matter by decreasing the dynamical masses of s quarks. Before the onset of s quarks, the Landau level number of light quarks is directly dependent on the magnetic field strength B by a simple inverse proportional relation ki ,max≈Bi0/B with Bd0=5 ×1 019 G , which is approximately 2 times Bu0 of u quarks at a common chemical potential. When the magnetic field increases up to Bd0, almost all three flavors are lying in the lowest Landau level.

  6. Recent Results of Top Quark Physics from the Tevatron

    SciTech Connect

    Peters, R. Y.

    2015-07-09

    Twenty years after its discovery in 1995 by the CDF and D0 collaborations at the Tevatron proton-antiproton collider at Fermilab, the top quark still undergoes intensive studies at the Tevatron and the LHC at CERN. In this article, recent top quark physics results from CDF and D0 are reported. In particular, measurements of single top quark and double top quark production, the $t\\bar{t}$ forward-backward asymmetry and the top quark mass are discussed.

  7. Is the Binary Mass Ratio Distribution Separation-Dependent?

    NASA Astrophysics Data System (ADS)

    Gullikson, Kevin; Kraus, Adam L.

    2016-01-01

    Recent discoveries of planets orbiting retired A-stars on close orbits and young A-stars on very wide orbits have renewed interest in the properties of nearby intermediate-mass stars. Especially interesting are the young stars because directly-imaged planets orbiting them may be bright enough for characterization (e.g. HR 8799, Beta Pictoris, etc). However, intermediate-mass stars and especially young intermediate mass stars are part of multiple systems more often than not. Close stellar companions may affect the formation and orbital evolution of any planets, and the properties of the companions can help constrain the binary formation mechanism. The mass ratio distribution of a population of binary stars, especially if the distribution for close companions is significantly different from that of wide companions, is helpful to distinguish companions that were born in or affected by the circumstellar disk from those which formed through fragmentation of the molecular core. Previous imaging surveys have found that binary systems with A-type primary stars tend to have cool companions with extreme mass ratios. There are hints at a much flatter mass ratio distribution for close companions, but strong completeness effects complicate the picture. We have conducted a spectroscopic survey of ~400 nearby main sequence A- and B-type stars, aimed at detecting stellar companions as late as M4 for all orbital separations <100 AU. We have searched for companions to the stars by cross-correlating the spectra against model templates for F-M type stars; a significant peak in the cross-correlation function indicates a detection. Our cross-correlation technique can detect low-mass companions with orbits that are too wide to detect with radial velocity monitoring and too small to detect with imaging techniques, making it complementary to work already done. We will present results from our survey and compare the mass ratio distribution we measure to the corresponding distribution for

  8. The mass dependence of dwarf satellite galaxy quenching

    SciTech Connect

    Slater, Colin T.; Bell, Eric F. E-mail: ericbell@umich.edu

    2014-09-10

    We combine observations of the Local Group with data from the NASA-Sloan Atlas to show the variation in the quenched fraction of satellite galaxies from low-mass dwarf spheroidals and dwarf irregulars to more massive dwarfs similar to the Magellanic Clouds. While almost all of the low-mass (M {sub *} ≲ 10{sup 7} M {sub ☉}) dwarfs are quenched, at higher masses the quenched fraction decreases to approximately 40%-50%. This change in the quenched fraction is large and suggests a sudden change in the effectiveness of quenching that correlates with satellite mass. We combine this observation with models of satellite infall and ram pressure stripping to show that the low-mass satellites must quench within 1-2 Gyr of pericenter passage to maintain a high quenched fraction, but that many more massive dwarfs must continue to form stars today even though they likely fell into their host >5 Gyr ago. We also characterize how the susceptibility of dwarfs to ram pressure must vary as a function of mass if it is to account for the change in quenched fractions. Though neither model predicts the quenching effectiveness a priori, this modeling illustrates the physical requirements that the observed quenched fractions place on possible quenching mechanisms.

  9. Measurement of the top quark mass in the tt¯→ lepton+jets and tt¯→ dilepton channels using √s = 7   TeV ATLAS data

    SciTech Connect

    Aad, G.

    2015-07-17

    The top quark mass was measured in the channels tt¯→ lepton+jets and tt¯→ dilepton (lepton = e,μ) based on ATLAS data recorded in 2011. The data were taken at the LHC with a proton–proton centre-of-mass energy of √s = 7 TeV and correspond to an integrated luminosity of 4.6 fb–1. The tt¯→ lepton+jets analysis uses a three-dimensional template technique which determines the top quark mass together with a global jet energy scale factor (JSF), and a relative b-to-light-jet energy scale factor (bJSF), where the terms b-jets and light-jets refer to jets originating from b-quarks and u, d, c, s-quarks or gluons, respectively. The analysis of the tt¯→ dilepton channel exploits a one-dimensional template method using the mℓb observable, defined as the average invariant mass of the two lepton+b-jet pairs in each event. The top quark mass is measured to be 172.33 ± 0.75 (stat + JSF + bJSF) ± 1.02(syst) GeV, and 173.79 ± 0.54(stat) ± 1.30(syst) GeV in the tt¯→ lepton+jets and tt¯→ dilepton channels, respectively. Thus, the combination of the two results yields mtop = 172.99 ± 0.48(stat) ± 0.78(syst) GeV, with a total uncertainty of 0.91 GeV.

  10. Measurement of the top quark mass in the tt¯→ lepton+jets and tt¯→ dilepton channels using √s = 7   TeV ATLAS data

    DOE PAGESBeta

    Aad, G.

    2015-07-17

    The top quark mass was measured in the channels tt¯→ lepton+jets and tt¯→ dilepton (lepton = e,μ) based on ATLAS data recorded in 2011. The data were taken at the LHC with a proton–proton centre-of-mass energy of √s = 7 TeV and correspond to an integrated luminosity of 4.6 fb–1. The tt¯→ lepton+jets analysis uses a three-dimensional template technique which determines the top quark mass together with a global jet energy scale factor (JSF), and a relative b-to-light-jet energy scale factor (bJSF), where the terms b-jets and light-jets refer to jets originating from b-quarks and u, d, c, s-quarks ormore » gluons, respectively. The analysis of the tt¯→ dilepton channel exploits a one-dimensional template method using the mℓb observable, defined as the average invariant mass of the two lepton+b-jet pairs in each event. The top quark mass is measured to be 172.33 ± 0.75 (stat + JSF + bJSF) ± 1.02(syst) GeV, and 173.79 ± 0.54(stat) ± 1.30(syst) GeV in the tt¯→ lepton+jets and tt¯→ dilepton channels, respectively. Thus, the combination of the two results yields mtop = 172.99 ± 0.48(stat) ± 0.78(syst) GeV, with a total uncertainty of 0.91 GeV.« less

  11. Non-leptonic decays in an extended chiral quark model

    SciTech Connect

    Eeg, J. O.

    2012-10-23

    We consider the color suppressed (nonfactorizable) amplitude for the decay mode B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}. We treat the b-quark in the heavy quark limit and the energetic light (u,d,s) quarks within a variant of Large Energy Effective Theory combined with an extension of chiral quark models. Our calculated amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} is suppressed by a factor of order {Lambda}{sub QCD}/m{sub b} with respect to the factorized amplitude, as it should according to QCD-factorization. Further, for reasonable values of the (model dependent) gluon condensate and the constituent quark mass, the calculated nonfactorizable amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} can easily accomodate the experimental value. Unfortunately, the color suppressed amplitude is very sensitive to the values of these model dependent parameters. Therefore fine-tuning is necessary in order to obtain an amplitude compatible with the experimental result for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}.

  12. Characterization of the mass dependent transmission efficiency of a CIMS

    NASA Astrophysics Data System (ADS)

    Heinritzi, M.; Simon, M.; Steiner, G.; Wagner, A. C.; Kürten, A.; Hansel, A.; Curtius, J.

    2015-11-01

    Knowledge about mass discrimination effects in a Chemical Ionization Mass Spectrometer (CIMS) is crucial for quantifying e.g. the recently discovered Extremely Low Volatile Organic Compounds (ELVOCs) and other compounds for which no calibration standard exists so far. Here, we present a simple way of estimating mass discrimination effects of a nitrate based Chemical Ionization Atmospheric Pressure interface Time of Flight (CI-APi-TOF) mass spectrometer. Characterization of the mass discrimination is achieved by adding different perfluorinated acids to the mass spectrometer in amounts sufficient to deplete the primary ions significantly. The relative transmission efficiency can then be determined by comparing the decrease of signals from the primary ions and the increase of signals from the perfluorinated acids at higher masses. This method is in use already for PTR-MS, however its application to a CI-APi-TOF brings additional difficulties, namely clustering and fragmentation of the measured compounds, which can be treated with statistical analysis of the measured data, leading to self-consistent results. We also compare this method to a transmission estimation obtained with a setup using an Electrospray Ion source, a High Resolution Differential Mobility Analyzer and an electrometer, which estimates the transmission of the instrument without the CI source. Both methods give different transmission curves, indicating non-negligible mass discrimination effects of the CI source. The absolute transmission of the instrument without the CI source was estimated with the HR-DMA method to plateau between the m / z range of 127 and 568 Th at around 1.5 %, however for the CI source included, the depletion method showed a steady increase in relative transmission efficiency from the m / z range of the primary ion (mainly at 62 Th) to around 550 Th by a factor of around 5. The main advantages of the depletion method are that the instrument is used in the same operation mode as

  13. Measurements of observables in the pion-nucleon system, nuclear a- dependence of heavy quark production and rare decays of D and B mesons. Progress report, 1 December, 1990--15 February, 1992

    SciTech Connect

    Sadler, M.E.; Isenhower, L.D.

    1992-02-15

    This report discusses research on the following topics: pion-nucleon interactions; detector tomography facility; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral D and B mesons; N* collaboration at CEBAF; and pilac experiments. (LSP)

  14. Quarks and gluons at hadron colliders

    SciTech Connect

    Bodek, A.; CDF Collaboration

    1996-08-01

    Data from proton-antiproton collisions at high energy provide important information on constraining the quark and gluon distributions in the nucleon and place limits on quark substructure. The S asymmetry data constrains the slope of the d/u quark distributions and significantly reduces the systematic error on the extracted value of the W mass. Drell-Yan data at high invariant mass provides strong limits on quark substructure. Information on {alpha}{sub s} and the gluon distributions can be extracted from high P{sub T} jet data and direct photons.

  15. Nonequilibrium hadronization and constituent quark number scaling

    SciTech Connect

    Zschocke, Sven; Horvat, Szabolcs; Mishustin, Igor N.; Csernai, Laszlo P.

    2011-04-15

    The constituent quark number scaling of elliptic flow is studied in a nonequilibrium hadronization and freeze-out model with rapid dynamical transition from ideal, deconfined, and chirally symmetric quark-gluon plasma, to final noninteracting hadrons. In this transition a bag model of constituent quarks is considered, where the quarks gain constituent quark mass while the background bag field breaks up and vanishes. The constituent quarks then recombine into simplified hadron states, while chemical, thermal, and flow equilibrium break down one after the other. In this scenario the resulting temperatures and flow velocities of baryons and mesons are different. Using a simplified few source model of the elliptic flow, we are able to reproduce the constituent quark number scaling, with assumptions on the details of the nonequilibrium processes.

  16. Top-quark processes at NLO in production and decay

    SciTech Connect

    Campbell, John M.; Ellis, R.Keith

    2012-04-01

    We describe the implementation of top production and decay processes in the parton-level Monte Carlo program MCFM. By treating the top quark as being on-shell, we can factorize the amplitudes for top-pair production, s-channel single-top production, and t-channel single-top production into the product of an amplitude for production and an amplitude for decay. In this way we can retain all spin correlations. Both the production and the decay amplitudes are calculated consistently at next-to-leading order in alpha_s. The full dependence on the b-quark mass is also kept. Phenomenological results are presented for various kinematic distributions at the LHC and for the top quark forward-backward asymmetry at the Tevatron.

  17. Neutrino-driven Explosion of a 20 Solar-mass Star in Three Dimensions Enabled by Strange-quark Contributions to Neutrino–Nucleon Scattering

    NASA Astrophysics Data System (ADS)

    Melson, Tobias; Janka, Hans-Thomas; Bollig, Robert; Hanke, Florian; Marek, Andreas; Müller, Bernhard

    2015-08-01

    Interactions with neutrons and protons play a crucial role for the neutrino opacity of matter in the supernova core. Their current implementation in many simulation codes, however, is rather schematic and ignores not only modifications for the correlated nuclear medium of the nascent neutron star, but also free-space corrections from nucleon recoil, weak magnetism, or strange quarks, which can easily add up to changes of several 10% for neutrino energies in the spectral peak. In the Garching supernova simulations with the Prometheus-Vertex code, such sophistications have been included for a long time except for the strange-quark contributions to the nucleon spin, which affect neutral-current neutrino scattering. We demonstrate on the basis of a 20 {M}ȯ progenitor star that a moderate strangeness-dependent contribution of {g}{{a}}{{s}}=-0.2 to the axial-vector coupling constant {g}{{a}}≈ 1.26 can turn an unsuccessful three-dimensional (3D) model into a successful explosion. Such a modification is in the direction of current experimental results and reduces the neutral-current scattering opacity of neutrons, which dominate in the medium around and above the neutrinosphere. This leads to increased luminosities and mean energies of all neutrino species and strengthens the neutrino-energy deposition in the heating layer. Higher nonradial kinetic energy in the gain layer signals enhanced buoyancy activity that enables the onset of the explosion at ∼300 ms after bounce, in contrast to the model with vanishing strangeness contributions to neutrino–nucleon scattering. Our results demonstrate the close proximity to explosion of the previously published, unsuccessful 3D models of the Garching group.

  18. Binary accretion rates: dependence on temperature and mass ratio

    NASA Astrophysics Data System (ADS)

    Young, M. D.; Clarke, C. J.

    2015-09-01

    We perform a series of 2D smoothed particle hydrodynamics simulations of gas accretion on to binaries via a circumbinary disc, for a range of gas temperatures and binary mass ratios (q). We show that increasing the gas temperature increases the accretion rate on to the primary for all values of the binary mass ratio: for example, for q = 0.1 and a fixed binary separation, an increase of normalized sound speed by a factor of 5 (from our `cold' to `hot' simulations) changes the fraction of the accreted gas that flows on to the primary from 10 to ˜40 per cent. We present a simple parametrization for the average accretion rate of each binary component accurate to within a few per cent and argue that this parametrization (rather than those in the literature based on warmer simulations) is relevant to supermassive black hole accretion and all but the widest stellar binaries. We present trajectories for the growth of q during circumbinary disc accretion and argue that the period distribution of stellar `twin' binaries is strong evidence for the importance of circumbinary accretion. We also show that our parametrization of binary accretion increases the minimum mass ratio needed for spin alignment of supermassive black holes to q ˜ 0.4, with potentially important implications for the magnitude of velocity kicks acquired during black hole mergers.

  19. Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at $$\\sqrt{s}$$ = 7 TeV

    DOE PAGESBeta

    Chatrchyan, Serguei

    2014-08-21

    The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass,more » $$m_t^{pole}$$, or the strong coupling constant, $$\\alpha_S$$. With the parton distribution function set NNPDF2.3, a pole mass of 176.7$$^{+3.0}_{-2.8}$$ GeV is obtained when constraining $$\\alpha_S$$ at the scale of the Z boson mass, $m_Z$, to the current world average. Alternatively, by constraining $$m_t^{pole}$$ to the latest average from direct mass measurements, a value of $$\\alpha_S(m_Z)$$ = 0.1151$$^{+0.0028}_{-0.0027}$$ is extracted. This is the first determination of $$\\alpha_S$$ using events from top-quark production.« less

  20. Determination of the top-quark pole mass and strong coupling constant from the t t-bar production cross section in pp collisions at $\\sqrt{s}$ = 7 TeV

    SciTech Connect

    Chatrchyan, Serguei

    2014-08-21

    The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, $m_t^{pole}$, or the strong coupling constant, $\\alpha_S$. With the parton distribution function set NNPDF2.3, a pole mass of 176.7$^{+3.0}_{-2.8}$ GeV is obtained when constraining $\\alpha_S$ at the scale of the Z boson mass, $m_Z$, to the current world average. Alternatively, by constraining $m_t^{pole}$ to the latest average from direct mass measurements, a value of $\\alpha_S(m_Z)$ = 0.1151$^{+0.0028}_{-0.0027}$ is extracted. This is the first determination of $\\alpha_S$ using events from top-quark production.

  1. Mass Load Distribution Dependence of Mass Sensitivity of Magnetoelastic Sensors under Different Resonance Modes

    PubMed Central

    Zhang, Kewei; Zhang, Lin; Chai, Yuesheng

    2015-01-01

    Magnetoelastic sensors as an important type of acoustic wave sensors have shown great promise for a variety of applications. Mass sensitivity is a key parameter to characterize its performance. In this work, the effects of mass load distribution on the mass sensitivity of a magnetoelastic sensor under different resonance modes were theoretically investigated using the modal analysis method. The results show that the mass sensitivity and “nodal point” positions are related to the point displacement, which is determined by the motion patterns. The motion patterns are affected by resonance modes and mass load distribution. Asymmetrical mass load distribution causes the motion patterns lose symmetry and leads to the shift of “nodal point”. The mass sensitivity changing with mass load distribution behaves like a sine wave with decaying amplitude and the minimum mass sensitivity appears at the first valley. This study provides certain theoretical guidance for optimizing the mass sensitivity of a magnetoelastic sensor or other acoustic wave based sensors. PMID:26295233

  2. The Perception of Limb Orientation Depends on the Center of Mass

    ERIC Educational Resources Information Center

    van de Langenberg, Rolf; Kingma, Idsart; Beek, Peter J.

    2008-01-01

    Three experiments were conducted to test the hypothesis that the perception of limb orientation depends on inertial eigenvectors against the alternative that it depends on the center of mass. In all experiments, each participant pointed at visible targets with his or her occluded right arm while center-of-mass and inertial eigenvectors were…

  3. First measurement of the forward-backward asymmetry in bottom-quark pair production at high mass

    NASA Astrophysics Data System (ADS)

    Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d'Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D'Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D'Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Henry, S.; Herndon, M.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W.-M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.; CDF Collaboration

    2015-08-01

    We measure the particle-level forward-backward production asymmetry in b b ¯ pairs with masses (mb b ¯ ) larger than 150 GeV /c2 , using events with hadronic jets and employing jet charge to distinguish b from b ¯. The measurement uses 9.5 fb-1 of p p ¯ collisions at a center-of-mass energy of 1.96 TeV recorded by the CDF II detector. The asymmetry as a function of mb b ¯ is consistent with zero, as well as with the predictions of the standard model. The measurement disfavors a simple model including an axigluon with a mass of 200 GeV /c2 , whereas a model containing a heavier 345 GeV /c2 axigluon is not excluded.

  4. THE MASS DEPENDENCE BETWEEN PROTOPLANETARY DISKS AND THEIR STELLAR HOSTS

    SciTech Connect

    Andrews, Sean M.; Rosenfeld, Katherine A.; Kraus, Adam L.; Wilner, David J.

    2013-07-10

    We present a substantial extension of the millimeter (mm) wave continuum photometry catalog for circumstellar dust disks in the Taurus star-forming region, based on a new ''snapshot'' {lambda} = 1.3 mm survey with the Submillimeter Array. Combining these new data with measurements in the literature, we construct a mm-wave luminosity distribution, f(L{sub mm}), for Class II disks that is statistically complete for stellar hosts with spectral types earlier than M8.5 and has a 3{sigma} depth of roughly 3 mJy. The resulting census eliminates a longstanding selection bias against disks with late-type hosts, and thereby demonstrates that there is a strong correlation between L{sub mm} and the host spectral type. By translating the locations of individual stars in the Hertzsprung-Russell diagram into masses and ages, and adopting a simple conversion between L{sub mm} and the disk mass, M{sub d} , we confirm that this correlation corresponds to a statistically robust relationship between the masses of dust disks and the stars that host them. A Bayesian regression technique is used to characterize these relationships in the presence of measurement errors, data censoring, and significant intrinsic scatter: the best-fit results indicate a typical 1.3 mm flux density of {approx}25 mJy for 1 M{sub Sun} hosts and a power-law scaling L{sub mm}{proportional_to}M{sub *}{sup 1.5-2.0}. We suggest that a reasonable treatment of dust temperature in the conversion from L{sub mm} to M{sub d} favors an inherently linear M{sub d} {proportional_to}M{sub *} scaling, with a typical disk-to-star mass ratio of {approx}0.2%-0.6%. The measured rms dispersion around this regression curve is {+-}0.7 dex, suggesting that the combined effects of diverse evolutionary states, dust opacities, and temperatures in these disks imprint a full width at half-maximum range of a factor of {approx}40 on the inferred M{sub d} (or L{sub mm}) at any given host mass. We argue that this relationship between M{sub d

  5. Energy and mass dependence of isotopic enrichment in sputtering

    SciTech Connect

    Shutthanandan, V.; Zhang, J.; Ray, Pradosh

    2003-05-01

    When a solid surface containing more than one component is bombarded by energetic particles, the sputtered flux is found to deviated from the stoichiometric composition of the target. This is known as preferential sputtering. Usually the sputtered flux is enriched with the lighter-mass particles, particularly at small emission angles. As the bombardment of the target is continued, the target surface becomes depleted in the particles that are preferentially emitted and a steady state is eventually established, where the ratio of the sputtered particles becomes equal to the natural abundance ratio of the particles in the target.

  6. Isospin effects on the mass dependence of the balance energy

    SciTech Connect

    Gautam, Sakshi; Sood, Aman D.

    2010-07-15

    We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/A= 0.54 and 0.57 as well as isobaric systems with N/A= 0.5 and 0.58. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.

  7. Ladder operators and associated algebra for position-dependent effective mass systems

    NASA Astrophysics Data System (ADS)

    Amir, Naila; Iqbal, Shahid

    2015-07-01

    An algebraic treatment of shape-invariant quantum-mechanical position-dependent effective mass systems is discussed. Using shape invariance, a general recipe for construction of ladder operators and associated algebraic structure of the pertaining system, is obtained. These operators are used to find exact solutions of general one-dimensional systems with spatially varying mass. We apply our formalism to specific translationally shape-invariant potentials having position-dependent effective mass.

  8. Nucleon structure in lattice QCD with dynamical domain-wall fermions quarks

    SciTech Connect

    Huey-Wen Lin; Shigemi Ohta

    2006-07-23

    We report RBC and RBC/UKQCD lattice QCD numerical calculations of nucleon electroweak matrix elements with dynamical domain-wall fermions (DWF) quarks. The first, RBC, set of dynamical DWF ensembles employs two degenerate flavors of DWF quarks and the DBW2 gauge action. Three sea quark mass values of 0.04, 0.03 and 0.02 in lattice units are used with about 200 gauge configurations each. The lattice cutoff is about 1.7 GeV and the spatial volume is about (1.9 fm){sup 3}. Despite the small volume, the ratio of the isovector vector and axial charges g{sub A}/g{sub V} and that of structure function moments {sub u-d}/{sub {Delta} u - {Delta} d} are in agreement with experiment, and show only very mild quark mass dependence. The second, RBC/UK, set of ensembles employs one strange and two degenerate (up and down) dynamical DWF quarks and Iwasaki gauge action. The strange quark mass is set at 0.04, and three up/down mass values of 0.03, 0.02 and 0.01 in lattice units are used. The lattice cutoff is about 1.6 GeV and the spatial volume is about (3.0 fm){sup 3}. Even with preliminary statistics of 25-30 gauge configurations, the ratios g{sub A}/g{sub V} and {sub u-d}/{sub {Delta} u - {Delta} d} are consistent with experiment and show only very mild quark mass dependence. Another structure function moment, d{sub 1}, though yet to be renormalized, appears small in both sets.

  9. NUCLEON STRUCTURE IN LATTICE QCD WITH DYNAMICAL DOMAIN--WALL FERMIONS QUARKS.

    SciTech Connect

    LIN H.-W.; OHTA, S.

    2006-10-02

    We report RBC and RBC/UKQCD lattice QCD numerical calculations of nucleon electroweak matrix elements with dynamical domain-wall fermions (DWF) quarks. The first, RBC, set of dynamical DWF ensembles employs two degenerate flavors of DWF quarks and the DBW2 gauge action. Three sea quark mass values of 0.04, 0.03 and 0.02 in lattice units are used with 220 gauge configurations each. The lattice cutoff is a{sup -1} {approx} 1.7GeV and the spatial volume is about (1.9fm){sup 3}. Despite the small volume, the ratio of the isovector vector and axial charges g{sub A}/g{sub V} and that of structure function moments {sub u-d}/{sub {Delta}u-{Delta}d} are in agreement with experiment, and show only very mild quark mass dependence. The second, RBC/UK, set of ensembles employs one strange and two degenerate (up and down) dynamical DWF quarks and Iwasaki gauge action. The strange quark mass is set at 0.04, and three up/down mass values of 0.03, 0.02 and 0.01 in lattice units are used. The lattice cutoff is a{sup -1} {approx} 1.6GeV and the spatial volume is about (3.0fm){sup 3}. Even with preliminary statistics of 25-30 gauge configurations, the ratios g{sub A}/g{sub V} and {sub u-d}/{sub {Delta}u-{Delta}d} are consistent with experiment and show only very mild quark mass dependence. Another structure function moment, d{sub 1}, though yet to be renormalized, appears small in both sets.

  10. Properties of the Top Quark

    SciTech Connect

    Wicke, Daniel; /Wuppertal U., Dept. Math.

    2009-08-01

    Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.

  11. Search for Charged Higgs in Top Quark Decays at CDF

    SciTech Connect

    Yu Geumbong

    2008-11-23

    We present a direct search result for a charged Higgs boson in lepton+jets tt-bar events using 2.2 fb{sup -1} data collected by CDF II detector. The charged Higgs boson is predicted to decay into cs-bar in low tan {beta} in the MSSM if its mass is smaller than the top quark. Looking for a second peak from the di-jet invariant mass in decays of top quark, there is observed no evidence of anomalous boson. We place the upper limits on the br(t{yields}H{sup +}b) = 0.1{approx}0.3 with 95% C.L. depending on the charged Higgs mass.

  12. Mass-dependent channel electron multiplier operation. [for ion detection

    NASA Technical Reports Server (NTRS)

    Fields, S. A.; Burch, J. L.; Oran, W. A.

    1977-01-01

    The absolute counting efficiency and pulse height distributions of a continuous-channel electron multiplier used in the detection of hydrogen, argon and xenon ions are assessed. The assessment technique, which involves the post-acceleration of 8-eV ion beams to energies from 100 to 4000 eV, provides information on counting efficiency versus post-acceleration voltage characteristics over a wide range of ion mass. The charge pulse height distributions for H2 (+), A (+) and Xe (+) were measured by operating the experimental apparatus in a marginally gain-saturated mode. It was found that gain saturation occurs at lower channel multiplier operating voltages for light ions such as H2 (+) than for the heavier ions A (+) and Xe (+), suggesting that the technique may be used to discriminate between these two classes of ions in electrostatic analyzers.

  13. Indirect handle on the down-quark Yukawa coupling.

    PubMed

    Goertz, Florian

    2014-12-31

    To measure the Yukawa couplings of the up and down quarks, Yu,d, seems to be far beyond the capabilities of current and (near) future experiments in particle physics. By performing a general analysis of the potential misalignment between quark masses and Yukawa couplings, we derive predictions for the magnitude of induced flavor-changing neutral currents (FCNCs), depending on the shift in the physical Yukawa coupling of first-generation quarks. We find that a change of more than 50% in Yd would generically result in ds transitions in conflict with kaon physics. This could already be seen as evidence for a nonvanishing direct coupling of the down quark to the newly discovered Higgs boson. The nonobservation of certain--already well-constrained--processes is thus turned into a powerful indirect measure of otherwise basically unaccessible physical parameters of the effective standard model. Similarly, improvements in limits on FCNCs in the up-type quark sector can lead to valuable information on Yu. PMID:25615309

  14. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD

    NASA Astrophysics Data System (ADS)

    Berger, Edmond L.; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-01

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.

  15. Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

    PubMed

    Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing

    2016-05-27

    We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon. PMID:27284650

  16. Predictions for the top-quark forward-backward asymmetry at high invariant pair mass using the principle of maximum conformality

    DOE PAGESBeta

    Wang, Sheng -Quan; Wu, Xing -Gang; Si, Zong -Guo; Brodsky, Stanley J.

    2016-01-07

    In this study, the D0 collaboration at FermiLab has recently measured the top-quark pair forward-backward asymmetry inmore » $$\\bar{p}p$$ → $$t\\bar{t}$$X reactions as a function of the $$t\\bar{t}$$ invariant mass M$$t\\bar{t}$$. The D0 result for AFB(M$$t\\bar{t}$$ > 650 GeV) is smaller than AFB(M$$t\\bar{t}$$) obtained for small values of M$$t\\bar{t}$$, which may indicate an “increasing-decreasing” behavior for AFB(M$$t\\bar{t}$$ > Mcut). This behavior is not explained using conventional renormalization scale setting, or even by a next-to-next-to-leading order (N2LO) QCD calculation—one predicts a monotonically increasing behavior. In the conventional scale-setting method, one simply guesses a single renormalization scale μr for the argument of the QCD running coupling and then varies it over an arbitrary range. However, the conventional method has inherent difficulties.« less

  17. Measurements of the Top-quark Mass and the $t\\bar{t}$ Cross Section in the Hadronic $\\tau +$ Jets Decay Channel at $\\sqrt{s} = 1.96$ TeV

    SciTech Connect

    Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Arisawa, T.; Artikov, A.; /Dubna, JINR /Texas A-M

    2012-08-01

    We present the first direct measurement of the top-quark mass using t{bar t} events decaying in the hadronic {tau} + jets decay channel. Using data corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron, we measure the t{bar t} cross section, {sigma}{sub t{bar t}}, and the top-quark mass, M{sub top}. We extract M{sub top} from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure {sigma}{sub t{bar t}} = 8.8 {+-} 3.3 (stat) {+-} 2.2 (syst) pb and M{sub top} = 172.7 {+-} 9.3 (stat) {+-} 3.7 (syst) GeV/c{sup 2}.

  18. Diquark mass differences from unquenched lattice QCD

    NASA Astrophysics Data System (ADS)

    Bi, Yujiang; Cai, Hao; Chen, Ying; Gong, Ming; Liu, Zhaofeng; Qiao, Hao-Xue; Yang, Yi-Bo

    2016-07-01

    We calculate diquark correlation functions in the Landau gauge on the lattice using overlap valence quarks and 2+1-flavor domain wall fermion configurations. Quark masses are extracted from the scalar part of quark propagators in the Landau gauge. The scalar diquark quark mass difference and axial vector scalar diquark mass difference are obtained for diquarks composed of two light quarks and of a strange and a light quark. The light sea quark mass dependence of the results is examined. Two lattice spacings are used to check the discretization effects. The coarse and fine lattices are of sizes 243 × 64 and 323 × 64 with inverse spacings 1/a = 1.75(4) GeV and 2.33(5) GeV, respectively. Supported by National Science Foundation of China (11575197, 10835002, 11405178, 11335001), joint funds of NSFC (U1232109), MG and ZL are partially supported by the Youth Innovation Promotion Association of CAS (2015013, 2011013), YC and ZL acknowledge support of NSFC and DFG (CRC110)

  19. Stevenson's optimized perturbation theory applied to factorization and mass scheme dependence

    NASA Astrophysics Data System (ADS)

    David Politzer, H.

    1982-01-01

    The principles of the optimized perturbation theory proposed by Stevenson to deal with coupling constant scheme dependence are applied to the problem of factorization scheme dependence in inclusive hadron reactions. Similar considerations allow the optimization of problems with mass dependence. A serious shortcoming of the procedure, common to all applications, is discussed.

  20. Measurement of the top quark mass with the dynamical likelihood method using lepton plus jets events with b-tags in p anti-p collisions at s**(1/2) = 1.96-TeV

    SciTech Connect

    Abulencia, A.; Acosta, D.; Adelman, Jahred A.; Affolder, Anthony A.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

    2005-12-01

    This report describes a measurement of the top quark mass, M{sub top}, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/anti-top (t{bar t}) pairs in p{bar p} collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb{sup -1}. They use the t{bar t} candidates in the ''lepton+jets'' decay channel, requiring at least one jet identified as a b quark by finding an displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of M{sub top} per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 t{bar t} candidates observed in the data, with 9.2 events expected from background, they measure the top quark mass to be 173.2{sub -2.4}{sup +2.6}(stat.) {+-} 3.2(syst.) GeV/c{sup 2}, or 173.2{sub -4.0}{sup +4.1} GeV/c{sup 2}.

  1. Semiclassical projection of hedgehog models with quarks

    SciTech Connect

    Cohen, T.D.; Broniowski, W.

    1986-12-01

    A simple semiclassical method is presented for calculating physical observables in states with good angular momentum and isospin for models whose mean-field solutions are hedgehogs. The method is applicable for theories which have both quark and meson degrees of freedom. The basic approach is to find slowly rotating solutions to the time-dependent mean-field equations. A nontrivial set of differential equations must be solved to find the quark configuration for these rotating hedgehogs. The parameters which specify the rotating solutions are treated as the collective degrees of freedom. They are requantized by imposing a set of commutation relations which ensures the correct algebra for the SU(2) x SU(2) group of angular momentum and isospin. Collective wave functions can then be found and with these wave functions all matrix elements can be calculated. The method is applied to a simple version of the chiral quark-meson model. A number of physical quantities such as magnetic moments, charge distributions, g/sub A/, g/sub ..pi..//sub N//sub N/, N-..delta.. mass splitting, properties of the N-..delta.. transition, etc., are calculated.

  2. Semiclassical projection of hedgehog models with quarks

    NASA Astrophysics Data System (ADS)

    Cohen, Thomas D.; Broniowski, Wojciech

    1986-12-01

    A simple semiclassical method is presented for calculating physical observables in states with good angular momentum and isospin for models whose mean-field solutions are hedgehogs. The method is applicable for theories which have both quark and meson degrees of freedom. The basic approach is to find slowly rotating solutions to the time-dependent mean-field equations. A nontrivial set of differential equations must be solved to find the quark configuration for these rotating hedgehogs. The parameters which specify the rotating solutions are treated as the collective degrees of freedom. They are requantized by imposing a set of commutation relations which ensures the correct algebra for the SU(2)×SU(2) group of angular momentum and isospin. Collective wave functions can then be found and with these wave functions all matrix elements can be calculated. The method is applied to a simple version of the chiral quark-meson model. A number of physical quantities such as magnetic moments, charge distributions, gA, gπNN, N-Δ mass splitting, properties of the N-Δ transition, etc., are calculated.

  3. Strongly coupled quark gluon plasma (SCQGP)

    NASA Astrophysics Data System (ADS)

    Bannur, Vishnu M.

    2006-07-01

    We propose that the reason for the non-ideal behaviour seen in lattice simulation of quark gluon plasma (QGP) and ultrarelativistic heavy ion collision experiments is that the QGP near Tc and above is a strongly coupled plasma (SCP), i.e., a strongly coupled quark gluon plasma (SCQGP). It is remarkable that the widely used equation of state of SCP in QED (quantum electrodynamics) very nicely fits lattice results on all QGP systems, with proper modifications to include colour degrees of freedom and the running coupling constant. Results on pressure in pure gauge, 2-flavours and 3-flavours QGP can all be explained by treating QGP as SCQGP, as demonstrated here. Energy density and speed of sound are also presented for all three systems. We further extend the model to systems with finite quark mass and reasonably good fits to lattice results are obtained for (2+1)-flavours and 4-flavours QGP. Hence it is a unified model, namely SCQGP, to explain the non-ideal QGP seen in lattice simulations with just two system dependent parameters.

  4. Top Quark Production at the Tevatron

    SciTech Connect

    Mietlicki, David J.

    2011-12-01

    The top quark is the most recently discovered of the standard model quarks, and because of its very large mass, studies of the top quark and its interactions are important both as tests of the standard model and searches for new phenomena. In this document, recent results of analyses of top quark production, via both the electroweak and strong interactions, from the CDF and D0 experiments are presented. The results included here utilize a dataset corresponding to up to 6 fb{sup -1} of integrated luminosity, slightly more than half of the dataset recorded by each experiment before the Tevatron was shutdown in September 2011.

  5. Top Quark Physics at the CDF Experiment

    SciTech Connect

    Stelzer, Bernd; Collaboration, for the CDF

    2010-07-01

    Fermilab's Tevatron accelerator is recently performing at record luminosities that enables a program systematically addressing the physics of top quarks. The CDF collaboration has analyzed up to 5 fb{sup -1} of proton anti-proton collisions from the Tevatron at a center of mass energy of 1.96 TeV. The large datasets available allow to push top quark measurements to higher and higher precision and have lead to the recent observation of electroweak single top quark production at the Tevatron. This article reviews recent results on top quark physics from the CDF experiment.

  6. Measurement of the p anti-p ---> t anti-t production cross- section and the top quark mass at s**(1/2) = 1.96-TeV in the all-hadronic decay mode

    SciTech Connect

    Aaltonen, T.; Abulencia, A.; Adelman, J.; Affolder, Anthony Allen; Akimoto, T.; Albrow, Michael G.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Fermilab /Frascati /Comenius U.

    2007-06-01

    We report the measurements of the t{bar t} production cross section and of the top quark mass using 1.02 fb{sup -1} of p{bar p} data collected with the CDF II detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be identified as initiated by a b-quark candidate by the reconstruction of a secondary vertex. The cross section is measured to be {sigma}{sub t{bar t}} = 8.3 {+-} 1.0(stat. ){sup +2.0}{sub -1.5}(syst.) {+-} 0.5(lumi.) pb, which is consistent with the standard model prediction. The top quark mass of 174.0 {+-} 2.2(stat.){+-}4.8(syst.) GeV/c{sup 2} is derived from a likelihood fit incorporating reconstructed mass distributions representative of signal and background.

  7. Peturbative gluon exchange in a covariant quark model of the pion

    SciTech Connect

    Ito, Hiroshi; Buck, W.W. . Dept. of Physics); Gross, F. . Dept. of Physics Continuous Electron Beam Accelerator Facility, Newport News, VA )

    1990-01-01

    A covariant pion wave function, which reproduces the low energy data, is used to calculate the perturbative gluon exchange contributions to the pion charge form factor. It is found that the perturbative process dominates at q > 3.5 GeV/c. The dependence on the quark mass and the asymptotic behavior of the form factor are explicitly displayed.

  8. a Body Mass Dependent Mechanical Impedance Model for Applications in Vibration Seat Testing

    NASA Astrophysics Data System (ADS)

    BOILEAU, P.-É.; RAKHEJA, S.; WU, X.

    2002-05-01

    A three degree-of-freedom model is proposed to predict the biodynamic responses of the seated human body of different masses. A baseline model is initially derived to satisfy both the mean apparent mass and seat-to-head transmissibility responses proposed in ISO/DIS 5982:2000 applicable for mean body mass of 75 kg. The validity of the resultant generic mass dependent model is verified by comparing the apparent mass and driving-point mechanical impedance responses computed for total body masses of 55, 75 and 90 kg with the range of idealized values proposed for body masses within the 49-93 kg range. Considering the lack of data that could be found to define the apparent mass/mechanical impedance of subjects with different body masses when applying the experimental conditions defined in ISO/DIS 5982:2000, an attempt is made to adapt the parameters of the base model to fit the measured apparent mass data applicable to groups of automobile occupants within different mass ranges. This is achieved through constrained parametric optimization which consists of minimizing the sum of squared errors between the computed response and the mean apparent mass data measured for automobile occupants within four mass groups: less than 60 kg, 60·5-70·5 kg, 70·5-80 kg and above 80 kg. The results show a reasonably good agreement between the model responses and the measured apparent mass data, particularly at frequencies below 10 Hz. The results suggest that the proposed mass dependent model can effectively predict the apparent mass responses of automobile occupants over a wide range of body masses and for two different postures: passenger (hands-in-lap) and driver (hands-on-steering wheel) postures.

  9. Measurements of top quark properties at the Tevatron collider

    SciTech Connect

    Margaroli, Fabrizio

    2011-05-01

    The discovery of the top quark in 1995 opened a whole new sector of investigation of the Standard Model; today top quark physics remains a key priority of the Tevatron program. Some of the measurements of top quark properties, for example its mass, will be a long-standing legacy. The recent evidence of an anomalously large charge asymmetry in top quark events suggests that new physics could couple preferably with top quarks. I will summarize this long chapter of particle physics history and discuss the road the top quark is highlighting for the LHC program.

  10. B B interactions with static bottom quarks from lattice QCD

    NASA Astrophysics Data System (ADS)

    Bicudo, Pedro; Cichy, Krzysztof; Peters, Antje; Wagner, Marc

    2016-02-01

    The isospin, spin and parity dependent potential of a pair of B mesons is computed using Wilson twisted mass lattice QCD with two flavors of degenerate dynamical quarks. The B meson is addressed in the static-light approximation, i.e. the b quarks are infinitely heavy. From the results of the B B meson-meson potentials, a simple rule can be deduced stating which isospin, spin and parity combinations correspond to attractive and which to repulsive forces. We provide fits to the ground state potentials in the attractive channels and discuss the potentials in the repulsive and excited channels. The attractive channels are the most important since they can possibly lead to a bound four-quark state, i.e. a b ¯b ¯u d tetraquark. Using these attractive potentials in the Schrödinger equation, we find an indication for such a tetraquark state of two static bottom antiquarks and two light u /d quarks with mass extrapolated down to the physical value.

  11. Production and decay of heavy top quarks

    SciTech Connect

    Kauffman, R.P.

    1989-08-01

    Experimental evidence indicates that the top quark exists and has a mass between 50 and 200 GeV/c{sup 2}. The decays of a top quark with a mass in this range are studied with emphasis placed on the mass region near the threshold for production of real W bosons. Topics discussed are: (1) possible enhancement of strange quark production when M{sub W} + m{sub s} < m{sub t} < M{sub W} + m{sub b}; (2) exclusive decays of T mesons to B and B{asterisk} mesons using the non-relativistic quark model; (3) polarization of intermediate W's in top quark decay as a source of information on the top quark mass. The production of heavy top quarks in an e{sup +}e{sup {minus}} collider with a center-of-mass energy of 2 TeV is studied. The effective-boson approximation for photons, Z{sup 0}'s and W's is reviewed and an analogous approximation for interfaces between photons and Z{sup 0}'s is developed. The cross sections for top quark pair production from photon-photon, photon-Z{sup 0}, Z{sup 0}Z{sup 0}, and W{sup +}W{sup {minus}} fusion are calculated using the effective-boson approximation. Production of top quarks along with anti-bottom quarks via {gamma}W{sup +} and Z{sup 0}W{sup +} fusion is studied. An exact calculation of {gamma}e{sup +} {yields} {bar {nu}}t{bar b} is made and compared with the effective-W approximation. 31 refs., 46 figs.

  12. Search for the production of single vector-like and excited quarks in the Wt final state in pp collisions at √{s}=8 TeV with the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Affolder, A. A.; Agatonovic-Jovin, T.; Agricola, J.; Aguilar-Saavedra, J. A.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Alkire, S. P.; Allbrooke, B. M. M.; Allport, P. P.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Álvarez Piqueras, D.; Alviggi, M. G.; Amadio, B. T.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anders, J. K.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Arabidze, G.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arduh, F. A.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, B.; Ayoub, M. K.; Azuelos, G.; Baak, M. A.; Baas, A. E.; Baca, M. J.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Baldin, E. M.; Balek, P.; Balestri, T.; Balli, F.; Balunas, W. K.; Banas, E.; Bandyopadhyay, A.; Banerjee, Sw.; Bannoura, A. A. E.; Barak, L.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnes, S. L.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Basalaev, A.; Bassalat, A.; Basye, A.; Bates, R. L.; Batista, S. J.; Batley, J. R.; Battaglia, M.; Bauce, M.; Bauer, F.; Bawa, H. S.; Beacham, J. B.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, M.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, J. K.; Belanger-Champagne, C.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bender, M.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Bentvelsen, S.; Beresford, L.; Beretta, M.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernard, N. R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bevan, A. J.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Biedermann, D.; Bieniek, S. P.; Biesuz, N. V.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biondi, S.; Bjergaard, D. M.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blanco, J. E.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Blunier, S.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boehler, M.; Bogaerts, J. A.; Bogavac, D.; Bogdanchikov, A. G.; Bohm, C.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutle, S. K.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozic, I.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Breaden Madden, W. D.; Brendlinger, K.; Brennan, A. J.; Brenner, L.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Britzger, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Bruni, A.; Bruni, G.; Bruschi, M.; Bruscino, N.; Bryngemark, L.; Buanes, T.; Buat, Q.; Buchholz, P.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.; Bugge, M. K.; Bulekov, O.; Bullock, D.; Burckhart, H.; Burdin, S.; Burgard, C. D.; Burghgrave, B.; Burke, S.; Burmeister, I.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Butler, J. M.; Butt, A. I.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Buzykaev, A. R.; Cabrera Urbán, S.; Caforio, D.; Cairo, V. M.; Cakir, O.; Calace, N.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Caloba, L. P.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarda, S.; Camarri, P.; Cameron, D.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Campoverde, A.; Canale, V.; Canepa, A.; Cano Bret, M.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Carbone, R. M.; Cardarelli, R.; Cardillo, F.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Castaneda-Miranda, E.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Caudron, J.; Cavaliere, V.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerio, B. C.; Cerny, K.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cerv, M.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chan, Y. L.; Chang, P.; Chapman, J. D.; Charlton, D. G.; Chau, C. C.; Chavez Barajas, C. A.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, L.; Chen, S.; Chen, S.; Chen, X.; Chen, Y.; Cheng, H. C.; Cheng, Y.; Cheplakov, A.; Cheremushkina, E.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiarelli, G.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chitan, A.; Chizhov, M. V.; Choi, K.; Chouridou, S.; Chow, B. K. B.; Christodoulou, V.; Chromek-Burckhart, D.; Chudoba, J.; Chuinard, A. J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Cinca, D.; Cindro, V.; Cioara, I. A.; Ciocio, A.; Cirotto, F.; Citron, Z. H.; Ciubancan, M.; Clark, A.; Clark, B. L.; Clark, P. J.; Clarke, R. N.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coffey, L.; Cogan, J. G.; Colasurdo, L.; Cole, B.; Cole, S.; Colijn, A. P.; Collot, J.; Colombo, T.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Connell, S. H.; Connelly, I. A.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Côté, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. A.; Crispin Ortuzar, M.; Cristinziani, M.; Croft, V.; Crosetti, G.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cúth, J.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; D'Auria, S.; D'Onofrio, M.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dafinca, A.; Dai, T.; Dale, O.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Dandoy, J. R.; Dang, N. P.; Daniells, A. C.; Danninger, M.; Dano Hoffmann, M.; Dao, V.; Darbo, G.; Darmora, S.; Dassoulas, J.; Dattagupta, A.; Davey, W.; David, C.; Davidek, T.; Davies, E.; Davies, M.; Davison, P.; Davygora, Y.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; De, K.; de Asmundis, R.; De Benedetti, A.; De Castro, S.; De Cecco, S.; De Groot, N.; de Jong, P.; De la Torre, H.; De Lorenzi, F.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dedovich, D. V.; Deigaard, I.; Del Peso, J.; Del Prete, T.; Delgove, D.; Deliot, F.; Delitzsch, C. M.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Dell'Orso, M.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; DeMarco, D. A.; Demers, S.; Demichev, M.; Demilly, A.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deterre, C.; Dette, K.; Deviveiros, P. O.; Dewhurst, A.; Dhaliwal, S.; Di Ciaccio, A.; Di Ciaccio, L.; Di Domenico, A.; Di Donato, C.; Di Girolamo, A.; Di Girolamo, B.; Di Mattia, A.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Di Valentino, D.; Diaconu, C.; Diamond, M.; Dias, F. A.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Diglio, S.; Dimitrievska, A.; Dingfelder, J.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Djuvsland, J. I.; do Vale, M. A. B.; Dobos, D.; Dobre, M.; Doglioni, C.; Dohmae, T.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donati, S.; Dondero, P.; Donini, J.; Dopke, J.; Doria, A.; Dova, M. T.; Doyle, A. T.; Drechsler, E.; Dris, M.; Dubreuil, E.; Duchovni, E.; Duckeck, G.; Ducu, O. A.; Duda, D.; Dudarev, A.; Duflot, L.; Duguid, L.; Dührssen, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Durglishvili, A.; Duschinger, D.; Dutta, B.; Dyndal, M.; Eckardt, C.; Ecker, K. M.; Edgar, R. C.; Edson, W.; Edwards, N. C.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Elliot, A. A.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Endo, M.; Erdmann, J.; Ereditato, A.; Ernis, G.; Ernst, J.; Ernst, M.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Esposito, B.; Etienvre, A. I.; Etzion, E.; Evans, H.; Ezhilov, A.; Fabbri, L.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Falla, R. J.; Faltova, J.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Faucci Giannelli, M.; Favareto, A.; Fayard, L.; Fedin, O. L.; Fedorko, W.; Feigl, S.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Feremenga, L.; Fernandez Martinez, P.; Fernandez Perez, S.; Ferrando, J.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, A.; Fischer, C.; Fischer, J.; Fisher, W. C.; Flaschel, N.; Fleck, I.; Fleischmann, P.; Fletcher, G. T.; Fletcher, G.; Fletcher, R. R. M.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Flowerdew, M. J.; Formica, A.; Forti, A.; Fournier, D.; Fox, H.; Fracchia, S.; Francavilla, P.; Franchini, M.; Francis, D.; Franconi, L.; Franklin, M.; Frate, M.; Fraternali, M.; Freeborn, D.; French, S. T.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fulsom, B. G.; Fusayasu, T.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gach, G. P.; Gadatsch, S.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gao, J.; Gao, Y.; Gao, Y. 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P.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Oide, H.; Okamura, W.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Olivares Pino, S. A.; Oliveira Damazio, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onogi, K.; Onyisi, P. U. E.; Oram, C. J.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Oropeza Barrera, C.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero y Garzon, G.; Otono, H.; Ouchrif, M.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Ovcharova, A.; Owen, M.; Owen, R. E.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Padilla Aranda, C.; Pagáčová, M.; Pagan Griso, S.; Paganis, E.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Palestini, S.; Palka, M.; Pallin, D.; Palma, A.; Pan, Y. B.; Panagiotopoulou, E. St.; Pandini, C. E.; Panduro Vazquez, J. G.; Pani, P.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, M. A.; Parker, K. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pasqualucci, E.; Passaggio, S.; Pastore, F.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Patel, N. D.; Pater, J. R.; Pauly, T.; Pearce, J.; Pearson, B.; Pedersen, L. E.; Pedersen, M.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Pelikan, D.; Penc, O.; Peng, C.; Peng, H.; Penning, B.; Penwell, J.; Perepelitsa, D. V.; Perez Codina, E.; Pérez García-Estañ, M. T.; Perini, L.; Pernegger, H.; Perrella, S.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petroff, P.; Petrolo, E.; Petrucci, F.; Pettersson, N. E.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Pickering, M. A.; Piegaia, R.; Pignotti, D. T.; Pilcher, J. E.; Pilkington, A. D.; Pin, A. W. J.; Pina, J.; Pinamonti, M.; Pinfold, J. L.; Pingel, A.; Pires, S.; Pirumov, H.; Pitt, M.; Pizio, C.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Pluth, D.; Poettgen, R.; Poggioli, L.; Pohl, D.; Polesello, G.; Poley, A.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Pralavorio, P.; Pranko, A.; Prasad, S.; Prell, S.; Price, D.; Price, L. E.; Primavera, M.; Prince, S.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopapadaki, E.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Ptacek, E.; Puddu, D.; Pueschel, E.; Puldon, D.; Purohit, M.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Raddum, S.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Rajagopalan, S.; Rammensee, M.; Rangel-Smith, C.; Rauscher, F.; Rave, S.; Ravenscroft, T.; Raymond, M.; Read, A. L.; Readioff, N. P.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Rehnisch, L.; Reichert, J.; Reisin, H.; Rembser, C.; Ren, H.; Renaud, A.; Rescigno, M.; Resconi, S.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Richter, S.; Richter-Was, E.; Ricken, O.; Ridel, M.; Rieck, P.; Riegel, C. J.; Rieger, J.; Rifki, O.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Ristić, B.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Roe, S.; Røhne, O.; Rolli, S.; Romaniouk, A.; Romano, M.; Romano Saez, S. M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, P.; Rosendahl, P. L.; Rosenthal, O.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, J. H. N.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rubinskiy, I.; Rud, V. I.; Rudolph, C.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Russell, H. L.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Saavedra, A. F.; Sabato, G.; Sacerdoti, S.; Saddique, A.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Saha, P.; Sahinsoy, M.; Saimpert, M.; Saito, T.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Salazar Loyola, J. E.; Saleem, M.; Salek, D.; Sales De Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sammel, D.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sannino, M.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sasaki, O.; Sasaki, Y.; Sato, K.; Sauvage, G.; Sauvan, E.; Savage, G.; Savard, P.; Sawyer, C.; Sawyer, L.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schaefer, R.; Schaeffer, J.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Schiavi, C.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schmitt, S.; Schneider, B.; Schnellbach, Y. J.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schopf, E.; Schorlemmer, A. L. S.; Schott, M.; Schouten, D.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schuh, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwarz, T. A.; Schwegler, Ph.; Schweiger, H.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Sciacca, F. G.; Scifo, E.; Sciolla, G.; Scuri, F.; Scutti, F.; Searcy, J.; Sedov, G.; Sedykh, E.; Seema, P.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekhon, K.; Sekula, S. J.; Seliverstov, D. M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Serre, T.; Sessa, M.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shaw, S. M.; Shcherbakova, A.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shiyakova, M.; Shmeleva, A.; Shoaleh Saadi, D.; Shochet, M. J.; Shojaii, S.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Shushkevich, S.; Sicho, P.; Sidebo, P. E.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silver, Y.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simon, D.; Sinervo, P.; Sinev, N. B.; Sioli, M.; Siragusa, G.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinner, M. B.; Skottowe, H. P.; Skubic, P.; Slater, M.; Slavicek, T.; Slawinska, M.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, M. N. K.; Smith, R. W.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Sokhrannyi, G.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Song, H. Y.; Soni, N.; Sood, A.; Sopczak, A.; Sopko, B.; Sopko, V.; Sorin, V.; Sosa, D.; Sosebee, M.; Sotiropoulou, C. L.; Soualah, R.; Soukharev, A. M.; South, D.; Sowden, B. C.; Spagnolo, S.; Spalla, M.; Spangenberg, M.; Spanò, F.; Spearman, W. R.; Sperlich, D.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; St. Denis, R. D.; Stabile, A.; Staerz, S.; Stahlman, J.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Strubig, A.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Subramaniam, R.; Succurro, A.; Suchek, S.; Sugaya, Y.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, S.; Svatos, M.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tam, J. Y. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tannenwald, B. B.; Tannoury, N.; Tapia Araya, S.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, F. E.; Taylor, G. N.; Taylor, P. T. E.; Taylor, W.; Teischinger, F. A.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Temple, D.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Tepel, F.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, E. N.; Thompson, P. D.; Thompson, R. J.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thun, R. P.; Tibbetts, M. J.; Ticse Torres, R. E.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todome, K.; Todorov, T.; Todorova-Nova, S.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tolley, E.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; Truong, L.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsui, K. M.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turra, R.; Turvey, A. J.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urban, J.; Urquijo, P.; Urrejola, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valderanis, C.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Den Wollenberg, W.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vannucci, F.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloce, L. M.; Veloso, F.; Velz, T.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, T.; Wang, X.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Washbrook, A.; Wasicki, C.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; Wharton, A. M.; White, A.; White, M. J.; White, R.; White, S.; Whiteson, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wildauer, A.; Wilkens, H. G.; Williams, H. H.; Williams, S.; Willis, C.; Willocq, S.; Wilson, A.; Wilson, J. A.; Wingerter-Seez, I.; Winklmeier, F.; Winter, B. T.; Wittgen, M.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wu, M.; Wu, M.; Wu, S. L.; Wu, X.; Wu, Y.; Wyatt, T. R.; Wynne, B. M.; Xella, S.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yakabe, R.; Yamada, M.; Yamaguchi, D.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, S.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, Y.; Yao, W.-M.; Yap, Y. C.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yeletskikh, I.; Yen, A. L.; Yildirim, E.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yuen, S. P. Y.; Yurkewicz, A.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zalieckas, J.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zeng, Q.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zhang, D.; Zhang, F.; Zhang, G.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, R.; Zhang, R.; Zhang, X.; Zhang, Z.; Zhao, X.; Zhao, Y.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, C.; Zhou, L.; Zhou, L.; Zhou, M.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, S.; Zinonos, Z.; Zinser, M.; Ziolkowski, M.; Živković, L.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zurzolo, G.; Zwalinski, L.

    2016-02-01

    A search for vector-like quarks and excited quarks in events containing a top quark and a W boson in the final state is reported here. The search is based on 20.3 fb-1 of proton-proton collision data taken at the LHC at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector. Events with one or two leptons, and one, two or three jets are selected with the additional requirement that at least one jet contains a b-quark. Single-lepton events are also required to contain at least one large-radius jet from the hadronic decay of a high- p T W boson or a top quark. No significant excess over the expected background is observed and upper limits on the cross-section times branching ratio for different vector-like quark and excited-quark model masses are derived. For the excited-quark production and decay to Wt with unit couplings, quarks with masses below 1500 GeV are excluded and coupling-dependent limits are set. [Figure not available: see fulltext.

  13. Search for the production of single vector-like and excited quarks in the Wt final state in pp collisions at √s = 8 TeV with the ATLAS detector

    DOE PAGESBeta

    Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; et al

    2016-02-17

    A search for vector-like quarks and excited quarks in events containing a top quark and a W boson in the final state is reported here. The search is based on 20.3 fb-1 of proton-proton collision data taken at the LHC at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector. Events with one or two leptons, and one, two or three jets are selected with the additional requirement that at least one jet contains a b-quark. Single-lepton events are also required to contain at least one large-radius jet from the hadronic decay of a high-pT W boson ormore » a top quark. No significant excess over the expected background is observed and upper limits on the cross-section times branching ratio for different vector-like quark and excited-quark model masses are derived. As a result, for the excited-quark production and decay to Wt with unit couplings, quarks with masses below 1500 GeV are excluded and coupling-dependent limits are set.« less

  14. Schwinger functions, light-quark bound states and sigma terms

    NASA Astrophysics Data System (ADS)

    Höll, A.; Maris, P.; Roberts, C. D.; Wright, S. V.

    2006-11-01

    We explore the viability of using solely spacelike information about a Schwinger function to extract properties of bound states. In a concrete example it is not possible to determine properties of states with masses ≳1.2 GeV. Modern Dyson-Schwinger equation methods supply a well-constrained tool that provides access to hadron masses and σ-terms. We report values of the latter for a range of hadrons. Of interest is an analysis relating to a u,d scalar meson, which is compatible with a picture of the lightest 0 as a bound state of a dressed-quark and -antiquark supplemented by a material pion cloud. A constituent-quark σ-term is defined, which affords a means for assessing the flavour-dependence of dynamical chiral symmetry breaking.

  15. High Statistics Analysis using Anisotropic Clover Lattices: (IV) The Volume Dependence of the Light Hadron Masses

    SciTech Connect

    Beane, S R; Detmold, W; Lin, H W; Luu, T C; Orginos, K; Parreno, A; Savage, M J; Torok, A; Walker-Loud, A

    2011-07-01

    The volume dependence of the octet baryon masses and relations among them are explored with Lattice QCD. Calculations are performed with nf = 2 + 1 clover fermion discretization in four lattice volumes, with spatial extent L ? 2.0, 2.5, 3.0 and 4.0 fm, with an anisotropic lattice spacing of b_s ? 0.123 fm in the spatial direction, and b_t = b_s/3.5 in the time direction, and at a pion mass of m_\\pi ? 390 MeV. The typical precision of the ground-state baryon mass determination is dependence of the masses, the Gell-Mann Okubo mass-relation, and of other mass combinations. A comparison with the predictions of heavy baryon chiral perturbation theory is performed in both the SU(2)L ? SU(2)R and SU(3)L ? SU(3)R expansions. Predictions of the three-flavor expansion for the hadron masses are found to describe the observed volume dependences reasonably well. Further, the ?N? axial coupling constant is extracted from the volume dependence of the nucleon mass in the two-flavor expansion, with only small modifications in the three-flavor expansion from the inclusion of kaons and eta's. At a given value of m?L, the finite-volume contributions to the nucleon mass are predicted to be significantly smaller at m_\\pi ? 140 MeV than at m_\\pi ? 390 MeV due to a coefficient that scales as ? m_\\pi^3. This is relevant for the design of future ensembles of lattice gauge-field configurations. Finally, the volume dependence of the pion and kaon masses are analyzed with two-flavor and three-flavor chiral perturbation theory.

  16. Revisiting the boiling of primordial quark nuggets at nonzero chemical potential

    NASA Astrophysics Data System (ADS)

    Li, Ang; Liu, Tong; Gubler, Philipp; Xu, Ren-Xin

    2015-03-01

    The boiling of possible quark nuggets during the quark-hadron phase transition of the Universe at nonzero chemical potential is revisited within the microscopic Brueckner-Hartree-Fock approach employed for the hadron phase, using two kinds of baryon interactions as fundamental inputs. To describe the deconfined phase of quark matter, we use a recently developed quark mass density-dependent model with a fully self-consistent thermodynamic treatment of confinement. We study the baryon number limit Aboil (above which boiling may be important) with three typical values for the confinement parameter D. It is firstly found that the baryon interaction with a softer equation of state for the hadron phase would only lead to a small increase of Aboil . However, results depend sensitively on the confinement parameter in the quark model. Specifically, boiling might be important during the Universe cooling for a limited parameter range around D 1 / 2 = 170 MeV, a value satisfying recent lattice QCD calculations of the vacuum chiral condensate, while for other choices of this parameter, boiling might not happen and cosmological quark nuggets of 102 < A <1050 could survive.

  17. Quark and pion effective couplings from polarization effects

    NASA Astrophysics Data System (ADS)

    Braghin, Fábio L.

    2016-05-01

    A flavor SU(2) effective model for pions and quarks is derived by considering polarization effects departing from the usual quark-quark effective interaction induced by dressed gluon exchange, i.e. a global color model for QCD. For that, the quark field is decomposed into a component that yields light mesons and the quark-antiquark condensate, being integrated out by means of the auxiliary field method, and another component which yields constituent quarks, which is basically a background quark field. Within a long-wavelength and weak quark field expansion (or large quark effective mass expansion) of a quark determinant, the leading terms are found up to the second order in a zero-order derivative expansion, by neglecting vector mesons that are considerably heavier than the pion. Pions are considered in the structureless limit and, besides the chiral invariant terms that reproduce previously derived expressions, symmetry breaking terms are also presented. The leading chiral quark-quark effective couplings are also found corresponding to a NJL and a vector-NJL couplings. All the resulting effective coupling constants and parameters are expressed in terms of the current and constituent quark masses and of the coupling g.

  18. Feinberg-Horodecki states of a time-dependent mass distribution harmonic oscillator

    NASA Astrophysics Data System (ADS)

    Eshghi, M.; Sever, R.; Ikhdair, S. M.

    2016-07-01

    The solution of the Feinberg-Horodecki (FH) equation for a time-dependent mass (TDM) harmonic oscillator quantum system is studied. A certain interaction is applied to a mass m(t) to provide a particular spectrum of stationary energies. The related spectrum of the harmonic oscillator potential V(t) acting on the TDM m(t) oscillators is found. We apply the time version of the asymptotic iteration method (AIM) to calculate analytical expressions of the TDM stationary state energies and their wave functions. It is shown that the obtained solutions reduce to those of simple harmonic oscillator as the time-dependent mass reduces to m0.

  19. Intrinsic charm in a matched general-mass scheme

    NASA Astrophysics Data System (ADS)

    Ball, Richard D.; Bertone, Valerio; Bonvini, Marco; Forte, Stefano; Groth Merrild, Patrick; Rojo, Juan; Rottoli, Luca

    2016-03-01

    The FONLL general-mass variable-flavour number scheme provides a framework for the matching of a calculation in which a heavy quark is treated as a massless parton to one in which the mass dependence is retained throughout. We describe how the usual formulation of FONLL can be extended in such a way that the heavy quark parton distribution functions are freely parameterized at some initial scale, rather than being generated entirely perturbatively. We specifically consider the case of deep-inelastic scattering, in view of applications to PDF determination, and the possible impact of a fitted charm quark distribution on F2c is assessed.

  20. Physics of the Quark Model

    ERIC Educational Resources Information Center

    Young, Robert D.

    1973-01-01

    Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)

  1. Heavy quark production in pp collisions

    SciTech Connect

    McGaughey, P.L.; Quack, E.; Ruuskanen, P.V. |

    1995-07-01

    A systematic study of the inclusive single heavy quark and heavy-quark pair production cross sections in pp collisions is presented for RHIC and LHC energies. We compare with existing data when possible. The dependence of the rates on the renormalization and factorization scales is discussed. Predictions of the cross sections are given for two different sets of parton distribution functions.

  2. Strange Quark Star Crusts

    SciTech Connect

    Steiner, Andrew W.

    2007-02-27

    If strange quark matter is absolutely stable, some neutron stars may be strange quark stars. Strange quark stars are usually assumed to have a simple liquid surface. We show that if the surface tension of droplets of quark matter in the vacuum is sufficiently small, droplets of quark matter on the surface of a strange quark star may form a solid crust on top of the strange quark star. This solid crust can significantly modify the predictions for the photon emission for the surface in an observable way.

  3. Improved angular momentum evolution model for solar-like stars. II. Exploring the mass dependence

    NASA Astrophysics Data System (ADS)

    Gallet, F.; Bouvier, J.

    2015-05-01

    Context. Understanding the physical processes that dictate the angular momentum evolution of solar-type stars from birth to maturity remains a challenge for stellar physics. Aims: We aim to account for the observed rotational evolution of low-mass stars over the age range from 1 Myr to 10 Gyr. Methods: We developed angular momentum evolution models for 0.5 and 0.8 M⊙ stars. The parametric models include a new wind braking law based on recent numerical simulations of magnetised stellar winds, specific dynamo and mass-loss rate prescriptions, as well as core-envelope decoupling. We compare model predictions to the distributions of rotational periods measured for low-mass stars belonging to star-forming regions and young open clusters. Furthermore, we explore the mass dependence of model parameters by comparing these new models to the solar-mass models we developed earlier. Results: Rotational evolution models are computed for slow, median, and fast rotators at each stellar mass. The models reproduce reasonably well the rotational behaviour of low-mass stars between 1 Myr and 8-10 Gyr, including pre-main sequence to zero-age main sequence spin up, prompt zero-age main sequence spin down, and early-main sequence convergence of the surface rotation rates. Fast rotators are found to have systematically shorter disk lifetimes than moderate and slow rotators, thus enabling dramatic pre-main sequence spin up. They also have shorter core-envelope coupling timescales, i.e., more uniform internal rotation. As for the mass dependence, lower mass stars require significantly longer core-envelope coupling timescales than solar-type stars, which results in strong differential rotation developing in the stellar interior on the early main sequence. Lower mass stars also require a weaker braking torque to account for their longer spin-down timescale on the early main sequence, while they ultimately converge towards lower rotational velocities than solar-type stars in the longer term

  4. THE LOW-MASS STELLAR POPULATION IN L1641: EVIDENCE FOR ENVIRONMENTAL DEPENDENCE OF THE STELLAR INITIAL MASS FUNCTION

    SciTech Connect

    Hsu, Wen-Hsin; Hartmann, Lee; Allen, Lori; Hernandez, Jesus; Megeath, S. T.; Mosby, Gregory; Tobin, John J.; Espaillat, Catherine

    2012-06-10

    We present results from an optical photometric and spectroscopic survey of the young stellar population in L1641, the low-density star-forming region of the Orion A cloud south of the Orion Nebula Cluster (ONC). Our goal is to determine whether L1641 has a large enough low-mass population to make the known lack of high-mass stars a statistically significant demonstration of environmental dependence of the upper mass stellar initial mass function (IMF). Our spectroscopic sample consists of IR-excess objects selected from the Spitzer/IRAC survey and non-excess objects selected from optical photometry. We have spectral confirmation of 864 members, with another 98 probable members; of the confirmed members, 406 have infrared excesses and 458 do not. Assuming the same ratio of stars with and without IR excesses in the highly extincted regions, L1641 may contain as many as {approx}1600 stars down to {approx}0.1 M{sub Sun }, comparable within a factor of two to the ONC. Compared to the standard models of the IMF, L1641 is deficient in O and early B stars to a 3{sigma}-4{sigma} significance level, assuming that we know of all the massive stars in L1641. With a forthcoming survey of the intermediate-mass stars, we will be in a better position to make a direct comparison with the neighboring, dense ONC, which should yield a stronger test of the dependence of the high-mass end of the stellar IMF on environment.

  5. Quaternion family symmetry of quarks and leptons

    SciTech Connect

    Frigerio, Michele; Ma, Ernest; Kaneko, Satoru; Tanimoto, Morimitsu

    2005-01-01

    To a first approximation, the quark mixing matrix has {theta}{sub 13}{sup q}={theta}{sub 23}{sup q}=0, whereas the lepton mixing matrix has {theta}{sub 23}{sup l}={pi}/4. We show how this structure may be understood if the family symmetry is Q{sub 8}, the quaternion group of eight elements. We find three viable scenarios for the Majorana neutrino mass matrix, each depending on four parameters and predicting a specific mass spectrum. The phenomenology of the two Higgs doublets which generate the Yukawa sector is analyzed and testable predictions are derived. We discuss also the closely related model based on D{sub 4}, the symmetry group of the square.

  6. Quark-hadron phase transition in a neutron star under strong magnetic fields

    NASA Astrophysics Data System (ADS)

    Rabhi, A.; Pais, H.; Panda, P. K.; Providência, C.

    2009-11-01

    We study the effect of a strong magnetic field on the properties of neutron stars with a quark-hadron phase transition. It is shown that the magnetic field prevents the appearance of a quark phase, enhances the leptonic fraction, decreases the baryonic density extension of the mixed phase and stiffens the total equation of state, including both the stellar matter and the magnetic field contributions. Two parametrizations of a density-dependent static magnetic field, increasing, respectively, fast and slowly with the density and reaching 2-4 × 1018 G in the centre of the star, are considered. The compact stars with strong magnetic fields have maximum mass configurations with larger masses and radii and smaller quark fractions. The parametrization of the magnetic field with density has a strong influence on the star properties.

  7. Dependence of the quark-lepton complementarity on parametrizations of the Cabibbo-Kobayashi-Maskawa and Pontecorvo-Maki-Nakagawa-Sakata matrices

    NASA Astrophysics Data System (ADS)

    Zheng, Ya-Juan

    2010-04-01

    The quark-lepton complementarity (QLC) is very suggestive in understanding possible relations between quark and lepton mixing matrices. We explore the QLC relations in all the possible angle-phase parametrizations and point out that they can approximately hold in five parametrizations. Furthermore, the vanishing of the smallest mixing angles in the Cabibbo-Kobayashi-Maskawa and Pontecorvo-Maki-Nakagawa-Sakata matrices can make sure that the QLC relations exactly hold in those five parametrizations. Finally, the sensitivity of the QLC relations to radiative corrections is also discussed.

  8. The Top Quark, QCD, And New Physics.

    DOE R&D Accomplishments Database

    Dawson, S.

    2002-06-01

    The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculation of e{sup+}e{sup -}+ t{bar t} at next-to-leading-order QCD using the phase space slicing algorithm and the implications of a precision measurement of the top quark mass are discussed in detail. The associated production of a t{bar t} pair and a Higgs boson in either e{sup+}e{sup -} or hadronic collisions is presented at next-to-leading-order QCD and its importance for a measurement of the top quark Yulrawa coupling emphasized. Implications of the heavy top quark mass for model builders are briefly examined, with the minimal supersymmetric Standard Model and topcolor discussed as specific examples.

  9. THE TOP QUARK, QCD, AND NEW PHYSICS.

    SciTech Connect

    DAWSON,S.

    2002-06-01

    The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a laboratory for perturbative QCD. As examples of the relevance of QCD corrections in the top quark sector, the calculation of e{sup +}e{sup -} + t{bar t} at next-to-leading-order QCD using the phase space slicing algorithm and the implications of a precision measurement of the top quark mass are discussed in detail. The associated production of a t{bar t} pair and a Higgs boson in either e{sup +}e{sup -} or hadronic collisions is presented at next-to-leading-order QCD and its importance for a measurement of the top quark Yulrawa coupling emphasized. Implications of the heavy top quark mass for model builders are briefly examined, with the minimal supersymmetric Standard Model and topcolor discussed as specific examples.

  10. Review of Top Quark Physics Results

    SciTech Connect

    Kehoe, R.; Narain, M.; Kumar, A.

    2007-12-01

    As the heaviest known fundamental particle, the top quark has taken a central role in the study of fundamental interactions. Production of top quarks in pairs provides an important probe of strong interactions. The top quark mass is a key fundamental parameter which places a valuable constraint on the Higgs boson mass and electroweak symmetry breaking. Observations of the relative rates and kinematics of top quark final states constrain potential new physics. In many cases, the tests available with study of the top quark are both critical and unique. Large increases in data samples from the Fermilab Tevatron have been coupled with major improvements in experimental techniques to produce many new precision measurements of the top quark. The first direct evidence for electroweak production of top quarks has been obtained, with a resulting direct determination of V{sub tb}. Several of the properties of the top quark have been measured. Progress has also been made in obtaining improved limits on potential anomalous production and decay mechanisms. This review presents an overview of recent theoretical and experimental developments in this field. We also provide a brief discussion of the implications for further efforts.

  11. ANALYTICAL THEORY FOR THE INITIAL MASS FUNCTION. III. TIME DEPENDENCE AND STAR FORMATION RATE

    SciTech Connect

    Hennebelle, Patrick

    2013-06-20

    The present paper extends our previous theory of the stellar initial mass function (IMF) by including time dependence and by including the impact of the magnetic field. The predicted mass spectra are similar to the time-independent ones with slightly shallower slopes at large masses and peak locations shifted toward smaller masses by a factor of a few. Assuming that star-forming clumps follow Larson-type relations, we obtain core mass functions in good agreement with the observationally derived IMF, in particular, when taking into account the thermodynamics of the gas. The time-dependent theory directly yields an analytical expression for the star formation rate (SFR) at cloud scales. The SFR values agree well with the observational determinations of various Galactic molecular clouds. Furthermore, we show that the SFR does not simply depend linearly on density, as is sometimes claimed in the literature, but also depends strongly on the clump mass/size, which yields the observed scatter. We stress, however, that any SFR theory depends, explicitly or implicitly, on very uncertain assumptions like clump boundaries or the mass of the most massive stars that can form in a given clump, making the final determinations uncertain by a factor of a few. Finally, we derive a fully time dependent model for the IMF by considering a clump, or a distribution of clumps accreting at a constant rate and thus whose physical properties evolve with time. In spite of its simplicity, this model reproduces reasonably well various features observed in numerical simulations of converging flows. Based on this general theory, we present a paradigm for star formation and the IMF.

  12. Isotopic mass-dependence of metal cation diffusion coefficients in liquid water

    SciTech Connect

    Bourg, I.C.; Richter, F.M.; Christensen, J.N.; Sposito, G.

    2009-01-11

    Isotope distributions in natural systems can be highly sensitive to the mass (m) dependence of solute diffusion coefficients (D) in liquid water. Isotope geochemistry studies routinely have assumed that this mass dependence either is negligible (as predicted by hydrodynamic theories) or follows a kinetic-theory-like inverse square root relationship (D {proportional_to} m{sup -0.5}). However, our recent experimental results and molecular dynamics (MD) simulations showed that the mass dependence of D is intermediate between hydrodynamic and kinetic theory predictions (D {proportional_to} m{sup -{beta}} with 0 {<=} {beta} < 0.2 for Li{sup +}, Cl{sup -}, Mg{sup 2+}, and the noble gases). In this paper, we present new MD simulations and experimental results for Na{sup +}, K{sup +}, Cs{sup +}, and Ca{sup 2+} that confirm the generality of the inverse power-law relation D {proportional_to} m{sup -{beta}}. Our new findings allow us to develop a general description of the influence of solute valence and radius on the mass dependence of D for monatomic solutes in liquid water. This mass dependence decreases with solute radius and with the magnitude of solute valence. Molecular-scale analysis of our MD simulation results reveals that these trends derive from the exponent {beta} being smallest for those solutes whose motions are most strongly coupled to solvent hydrodynamic modes.

  13. Evolution of planetary systems with time-dependent stellar mass-loss

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.; Anderson, Kassandra R.; Bloch, Anthony M.

    2013-06-01

    Observations indicate that intermediate-mass stars, binary stars and stellar remnants often host planets; a complete explanation of these systems requires an understanding of how planetary orbits evolve as their central stars lose mass. Motivated by these dynamical systems, this paper generalizes in two directions previous studies of orbital evolution in planetary systems with stellar mass-loss: (1) many previous treatments focus on constant mass-loss rates and much of this work is carried out numerically. Here, we study a class of single planet systems where the stellar mass-loss rate is time dependent. The mass-loss rate can be increasing or decreasing, but the stellar mass always decreases monotonically. For this class of