Bounding CKM Mixing with a Fourth Family
Chanowitz, Michael S.
2009-04-22
CKM mixing between third family quarks and a possible fourth family is constrained by global fits to the precision electroweak data. The dominant constraint is from nondecoupling oblique corrections rather than the vertex correction to Z {yields} {bar b}b used in previous analyses. The possibility of large mixing suggested by some recent analyses of FCNC processes is excluded, but 3-4 mixing of the same order as the Cabbibo mixing of the first two families is allowed.
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.
Fourth SM family, breaking of mass democracy, and the CKM mixings
Atag, S.; Celikel, A.; Ciftci, A.K.; Sultansoy, S. |; Yilmaz, U.O.
1996-11-01
We consider the violation of the democratic mass matrix in the framework of the four-family standard model. Predictions of fourth-family fermion masses as well as quark and lepton CKM mixings are presented. Production and decay modes of new fermions are discussed. {copyright} {ital 1996 The American Physical Society.}
CKM-UT Angles: Mixing And CP Violation at the B Factories
Finocchiaro, Giuseppe; /Frascati
2011-11-07
We review the experimental status of the angles of the Unitarity Triangle of the CKM matrix, as measured by the BABAR and Belle experiments. The B Factories have demonstrated since the beginning of this decade that CP violation in the B meson system is consistent with the Standard Model (SM) description in terms of the complex phase in the three-by-three Cabibbo-Kobayashi-Maskawa (CKM) matrix. With one single phase, the SM predicts clear patterns for quark mixing and CP violations, to be satisfied by all processes.
Bounds on the mixing of the down-type quarks with vector-like singlet quarks
Lavoura, L.; Silva, J.P.
1992-09-08
We derive bounds on the mixing of the standard charge -1/3 quarks with vector-like isosinglet quarks, as they exist in some extensions of the standard model. We make no assumptions about the unitarity or any other features of the mixing matrix. We find that the mixing is quite constrained: we are able to set bounds on all the extra parameters which arise in the mixing matrix (CKM matrix), except on two phases. The assumption that there exists only one exotic quark leads to some extra relationships among the parameters of the mixing matrix.
Higgs Mass Constraints on a Fourth Family: Upper and Lower Limits on CKM Mixing
Chanowitz, Michael S.
2010-06-25
Theoretical and experimental limits on the Higgs boson mass restrict CKM mixing of a possible fourth family beyond the constraints previously obtained from precision electroweak data alone. Existing experimental and theoretical bounds on m{sub H} already significantly restrict the allowed parameter space. Zero CKM mixing is excluded and mixing of order {theta}{sub Cabbibo} is allowed. Upper and lower limits on 3-4 CKM mixing are exhibited as a function of m{sub H}. We use the default inputs of the Electroweak Working Group and also explore the sensitivity of both the three and four family fits to alternative inputs.
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.
Novel formulations of CKM matrix renormalization
Kniehl, Bernd A.; Sirlin, Alberto
2009-12-17
We review two recently proposed on-shell schemes for the renormalization of the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix in the Standard Model. One first constructs gauge-independent mass counterterm matrices for the up- and down-type quarks complying with the hermiticity of the complete mass matrices. Diagonalization of the latter then leads to explicit expressions for the CKM counterterm matrix, which are gauge independent, preserve unitarity, and lead to renormalized amplitudes that are non-singular in the limit in which any two quarks become mass degenerate. One of the schemes also automatically satisfies flavor democracy.
CKM and PMNS mixing matrices from discrete subgroups of SU(2)
NASA Astrophysics Data System (ADS)
Potter, Franklin
2015-07-01
Remaining within the realm of the Standard Model(SM) local gauge group, this first principles derivation of both the PMNS and CKM matrices utilizes quaternion generators of the three discrete (i.e., finite) binary rotational subgroups of SU(2) called [3,3,2], [4,3,2], and [5,3,2] for three lepton families in R3 and four related discrete binary rotational subgroups [3,3,3], [4,3,3], [3,4,3], and [5,3,3] represented by four quark families in R4. The traditional 3x3 CKM matrix is extracted as a submatrix of the 4x4 CKM4 matrix. If these two additional quarks b' and t' of a 4th quark family exist, there is the possibility that the SM lagrangian may apply all the way down to the Planck scale. There are then numerous other important consequences. The Weinberg angle is derived using these same quaternion generators, and the triangle anomaly cancellation is satisfied even though there is an obvious mismatch of three lepton families to four quark families. In a discrete space, one can also use these generators to derive a unique connection from the electroweak local gauge group SU(2)L x U(1)Y acting in R4 to the discrete group Weyl E8 in R8. By considering Lorentz transformations in discrete (3,1)-D spacetime, one obtains another Weyl E8 discrete symmetry group in R8, so that the combined symmetry is Weyl E8 x Weyl E8 = "discrete" SO(9,1) in 10-D spacetime. This unique connection is in direct contrast to the 10500 possible connections for superstring theory!
K 0- overlineK0 mixing and the CKM parameters (ϱ, η) from the Laplace sum rules
NASA Astrophysics Data System (ADS)
Narison, S.
1995-02-01
Using the Laplace sum rule (LSR) approach, which is less affected by the contribution of the higher mass hadronic states than the Finite Energy Sum Rule (FESR), we test the reliability of the existing estimate of the K 0- overlineK0 mixing parameter from the four-quark two-point correlator. We obtain, for the renormalization group invariant B-parameter [ {f K}/{(1.2f π) }] 2B̂K, the upper bound: 0.83 and the conservative estimate: 0.58 ± 0.22 from the LSR method. Combining the previous estimate with the updated value of f BB B=(1.49±0.14)f π obtained from the same LSR method, one can deduce the fitted values ( ϱ, η) f (0.09, 0.41) of the CKM parameters.
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.
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
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.
Recent developments on the CKM matrix
NASA Astrophysics Data System (ADS)
Wang, Wei
2014-07-01
In Standard Model, CP violation arises from an irreducible complex phase in the quark mixing matrix, now under the name Cabibbo-Kobayashi-Maskawa matrix. This description has shown remarkable overall agreement with various experimental measurements. In this review, we discuss recent experimental data and theoretical developments on three quantities of CKM matrix that are most uncertain: the Vub, including its magnitude and the phase γ in standard parametrization, and the Bs-\\bar Bs mixing phase βs.
Kirsch, Matthias
2009-06-29
At particle accelerators the Standard Model has been tested and will be tested further to a great precision. The data analyzed in this thesis have been collected at the world's highest energetic-collider, the Tevatron, located at the Fermi National Accelerator Laboratory (FNAL) in the vicinity of Chicago, IL, USA. There, protons and antiprotons are collided at a center-of-mass energy of {radical}s = 1.96 TeV. The discovery of the top quark was one of the remarkable results not only for the CDF and D0 experiments at the Tevatron collider, but also for the Standard Model, which had predicted the existence of the top quark because of symmetry arguments long before already. Still, the Tevatron is the only facility able to produce top quarks. The predominant production mechanism of top quarks is the production of a top-antitop quark pair via the strong force. However, the Standard Model also allows the production of single top quarks via the electroweak interaction. This process features the unique opportunity to measure the |V_{tb}| matrix element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix directly, without assuming unitarity of the matrix or assuming that the number of quark generations is three. Hence, the measurement of the cross section of electroweak top quark production is more than the technical challenge to extract a physics process that only occurs one out of ten billion collisions. It is also an important test of the V-A structure of the electroweak interaction and a potential window to physics beyond the Standard Model in the case where the measurement of |V{sub tb}| would result in a value significantly different from 1, the value predicted by the Standard Model. At the Tevatron two production processes contribute significantly to the production of single top quarks: the production via the t-channel, also called W-gluon fusion, and the production via the s-channel, known as well as W* process. This analysis searches for the combined s+t channel
Neutrino mixings and leptonic CP violation from CKM matrix and Majorana phases
Agarwalla, Sanjib Kumar; Parida, M. K.; Mohapatra, R. N.; Rajasekaran, G.
2007-02-01
The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale the quark and lepton mixing matrices are equal, then for quasidegenerate neutrinos radiative corrections can lead to large solar and atmospheric mixings and small reactor angle at the weak scale in agreement with data. Evidence for quasidegenerate neutrinos could, within this framework, be interpreted as being consistent with quark-lepton unification at high scale. In the current work, we extend this model to show that the hypothesis works quite successfully in the presence of CP-violating phases (which were set to zero in the first paper). In the case where the Pontecorvo-Maki-Nakagawa-Sakata matrix is identical to the Cabibbo-Kobayashi-Maskawa quark-mixing matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be ({approx_equal}0.3 deg.) and leptonic CP-violation parameter J{sub CP}{approx_equal}(4-8)x10{sup -5} and {theta}{sub 13}=3.5 deg. If on the other hand, the Pontecorvo-Maki-Nakagawa-Sakata matrix is assumed to also have non-negligible Majorana phase(s) initially, the resulting theory damps radiative magnification phenomenon for a large range of parameters but nevertheless has enough parameter space to give the two necessary large neutrino mixing angles. In this case, one has {theta}{sub 13}=3.5 deg. -10 deg. and vertical bar J{sub CP} vertical bar as large as 0.02-0.04 which are accessible to long baseline neutrino oscillation experiments.
Neutrino mixings and leptonic CP violation from CKM matrix and Majorana phases
NASA Astrophysics Data System (ADS)
Agarwalla, Sanjib Kumar; Parida, M. K.; Mohapatra, R. N.; Rajasekaran, G.
2007-02-01
The high scale mixing unification hypothesis recently proposed by three of us (R. N. M., M. K. P. and G. R.) states that if at the seesaw scale the quark and lepton mixing matrices are equal, then for quasidegenerate neutrinos radiative corrections can lead to large solar and atmospheric mixings and small reactor angle at the weak scale in agreement with data. Evidence for quasidegenerate neutrinos could, within this framework, be interpreted as being consistent with quark-lepton unification at high scale. In the current work, we extend this model to show that the hypothesis works quite successfully in the presence of CP-violating phases (which were set to zero in the first paper). In the case where the Pontecorvo-Maki-Nakagawa-Sakata matrix is identical to the Cabibbo-Kobayashi-Maskawa quark-mixing matrix at the seesaw scale, with a Dirac phase but no Majorana phase, the low energy Dirac phase is predicted to be (≃0.3°) and leptonic CP-violation parameter JCP≃(4-8)×10-5 and θ13=3.5°. If on the other hand, the Pontecorvo-Maki-Nakagawa-Sakata matrix is assumed to also have non-negligible Majorana phase(s) initially, the resulting theory damps radiative magnification phenomenon for a large range of parameters but nevertheless has enough parameter space to give the two necessary large neutrino mixing angles. In this case, one has θ13=3.5° 10° and |JCP| as large as 0.02 0.04 which are accessible to long baseline neutrino oscillation experiments.
Examining a right-handed quark mixing matrix with b-tags at the LHC
NASA Astrophysics Data System (ADS)
Fowlie, Andrew; Marzola, Luca
2015-05-01
Encouraged by a hint in a search for right-handed W bosons at the LHC, we investigate whether the unitarity of a right-handed quark mixing matrix and the equality of the left- and right-handed quark mixing matrices could be tested at the LHC. We propose a particular test, involving counting the numbers of b-tags in the final state, and simulate the test at the event level with Monte-Carlo tools for the forthcoming √{ s} = 13 TeV LHC run. We find that testing unitarity with 20 /fb will be challenging; our test successfully rejects unitarity if the right-handed quark mixing matrix is non-unitary, but only in particular cases. On the other hand, our test may provide the first opportunity to test the unitarity of a right-handed quark mixing matrix and with 3000 /fb severely constrains possible departures from unitarity in the latter. We refine our previous work, testing the equality of quark mixing matrices, with full collider simulation. With 20 /fb, we are sensitive to mixing angles as small as 30°, and with 3000 /fb, angles as small as 7.5°, confirming our preliminary analysis. We briefly investigate testing the unitarity of the SM CKM matrix with a similar method by studying semileptonic t t bar production, concluding that systematics make it particularly difficult.
NASA Astrophysics Data System (ADS)
Chu Wang, Ling-Lie
1981-01-01
Since this is an experimental conference I shall begin my talk with that spirit. We can view that the subject of my talk as a result of ''the ORY Collaboration'' with more than fifty theorists involved. The topics covered are the results of four task forces: I. The mixing Matrix Task Force, II.. The D-decay Task Force, III. the Boredom-Escaping Group and IV. the Far-and-Beyond Group.
Update on Angles and Sides of the CKM Unitarity Triangle from BaBar
Cheng, Chih-hsiang; /Caltech
2011-11-14
We report several recent updates from the BABAR Collaboration on the matrix elements |V{sub cb}|, |V{sub ub}|, and |V{sub td}| of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix, and the angles {beta} and {alpha} of the unitarity triangle. Most results presented here are using the full BABAR {Upsilon}(4S) data set.
The CKM Matrix from Lattice QCD
Mackenzie, Paul B.; /Fermilab
2009-07-01
Lattice QCD plays an essential role in testing and determining the parameters of the CKM theory of flavor mixing and CP violation. Very high precisions are required for lattice calculations analyzing CKM data; I discuss the prospects for achieving them. Lattice calculations will also play a role in investigating flavor mixing and CP violation beyond the Standard Model.
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.
Yang-Mills Duality as Origin of Generations, Quark Mixing, and Neutrino Oscillations
NASA Astrophysics Data System (ADS)
Tsou, Sheung Tsun
2002-08-01
The origin of fermion generations is one of the great mysteries in particle physics. We consider here a possible solution within the Standard Model framework based on a nonabelian generalization of electric-magnetic duality. First, nonabelian duality says that dual to the colour (electric) symmetry SU(3), there is a "colour magnetic symmetry" {SU}͠(3), which by a result of 't Hooft is spontaneously broken and can thus play the role of the "horizontal symmetry" of generations. Second, nonabelian duality suggests the manner this symmetry is broken with frame vectors in internal symmetry space acting as Higgs fields. As a result, mass matrices factorize leading to fermion mass hierarchy. At the tree level, there is no mixing but with loop corrections, the mass matrices rotate and mixing occurs. A calculation to first order gives mixing (CKM and MNS) matrices in general agreement with experiment. In particular, quark mixing is seen naturally to be weak compared with leptons, while within the lepton sector, μ - τ mixing turns out near maximal but e - τ mixing small, just as seen in recent ν oscillation experiments. In addition, the scheme leads to many testable predictions ranging from rare FCNC meson decays and μ - e conversion in nuclei to cosmic ray air showers above 1020 eV, which will be detailed in the followng talk by Chan.
Quark CP-phase and Froggatt-Nielsen mechanism
NASA Astrophysics Data System (ADS)
Hattori, Chuichiro; Matsuda, Masahisa; Matsunaga, Mamoru; Matsuoka, Takeo
2016-08-01
On the basis of the Froggatt-Nielsen mechanism, we study quark flavor mixings in the SU (6) × SU (2)R model. The characteristic structure of the CKM matrix is attributed to the hierarchical effective Yukawa couplings due to the Froggatt-Nielsen mechanism and also to the state-mixings beyond the MSSM. We elucidate the detailed form of the CKM matrix elements and find interesting relations between the CP violating phase and three mixing angles. Taking the existing data of three mixing angles, we estimate the quark CP-phase at δ = (75 ± 3) °. This result is in accord with observations.
Quark mixing sum rules and the right unitarity triangle
Antusch, Stefan; Spinrath, Martin; King, Stephen F.; Malinsky, Michal
2010-02-01
In analogy with the recently proposed lepton mixing sum rules, we derive quark mixing sum rules for the case of hierarchical quark mass matrices with 1-3 texture zeros, in which the separate up and down-type 1-3 mixing angles are approximately zero, and V{sub ub} is generated from V{sub cb} as a result of 1-2 up-type quark mixing. Using the sum rules, we discuss the phenomenological viability of such textures, including up to four texture zeros, and show how the right-angled unitarity triangle, i.e., {alpha}{approx_equal}90 deg., can be accounted for by a remarkably simple scheme involving real mass matrices apart from a single element being purely imaginary. In the framework of grand unified theories, we show how the quark and lepton mixing sum rules may combine to yield an accurate prediction for the reactor angle.
Semileptonic B Decays, B Mixing And Magnitudes of CKM Elements at BaBar
Cote, D.; /Montreal U.
2005-10-11
The value of |V{sub cb}| has been measured recently from a simultaneous fit to moments of the hadronic-mass and lepton-energy distributions in inclusive semileptonic B-mesons decays with a precision of 2%. Both exclusive and inclusive measurements of |V{sub ub}| have also been carried out in B {yields} X{sub u}{ell}{nu} decays. Precision measurements of the mixing parameter, {Delta}m{sub d}, have been obtained. In addition, direct limits on the total decay-rate difference {Delta}{Lambda} between the two B{sup 0} mass eigenstates and on CP, T and CPT violation due exclusively to oscillations have recently been provided by BaBar.
Quark flavor mixing and its physical implications. [Review
Wang, L.L.C.
1980-01-01
Developments on the subject of flavor mixing, especially the Kobayashi-Maskawa model, since the Tokyo conference in 1978 are reviewed. Aspects discussed include the following: history of the development of the understanding of weak interaction quark states, the determination of the mixing matrix V, nonleptonic decays (the ..delta..I = 1/2 rule of K decays, charm nonleptonic decays), the neutron electric dipole moment, decay interference from CP violation, dynamical origin of the quark flavor mixing, and alternatives to the three doublet model. 34 references, 1 figure. (RWR)
Quark mixing from Δ (6N2) family symmetry
NASA Astrophysics Data System (ADS)
Ishimori, Hajime; King, Stephen F.; Okada, Hiroshi; Tanimoto, Morimitsu
2015-04-01
We consider a direct approach to quark mixing based on the discrete family symmetry Δ (6N2) in which the Cabibbo angle is determined by a residual Z2 ×Z2 subgroup to be |Vus | = 0.222521, for N being a multiple of 7. We propose a particular model in which unequal smaller quark mixing angles and CP phases may occur without breaking the residual Z2 ×Z2 symmetry. We perform a numerical analysis of the model for N = 14, where small Z2 ×Z2 breaking effects of order 3% are allowed by model, allowing perfect agreement within the uncertainties of the experimentally determined best fit quark mixing values.
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.
Quark and lepton mixing as manifestations of violated mirror symmetry
Dyatlov, I. T.
2015-06-15
The existence of heavy mirror analogs of ordinary fermions would provide deeper insight into the gedanken paradox appearing in the Standard Model upon direct parity violation and consisting in a physical distinguishability of left- and right-hand coordinate frames. Arguments are presented in support of the statement that such mirror states may also be involved in the formation of observed properties of the system of Standard Model quarks and leptons—that is, their mass spectra and their weak-mixing matrices: (i) In the case of the involvement of mirror generations, the quark mixing matrix assumes the experimentally observed form. It is determined by the constraints imposed by weak SU(2) symmetry and by the quark-mass hierarchy. (ii) Under the same conditions and upon the involvement of mirror particles, the lepton mixing matrix (neutrino mixing) may become drastically different from its quark analog—the Cabibbo-Kobayashi-Maskawa matrix; that is, it may acquire properties suggested by experimental data. This character of mixing is also indicative of an inverse mass spectrum of Standard Model neutrinos and their Dirac (not Majorana) nature.
Lepton and quark mixing patterns from finite flavor symmetries
NASA Astrophysics Data System (ADS)
Yao, Chang-Yuan; Ding, Gui-Jun
2015-11-01
We perform a systematical and analytical study of lepton mixing which can be derived from the subgroups of S U (3 ) under the assumption that neutrinos are Dirac particles. We find that type D groups can predict lepton mixing patterns compatible with the experimental data at the 3 σ level. The lepton mixing matrix turns out to be of the trimaximal form, and the Dirac C P violating phase is trivial. Moreover, we extend the flavor symmetry to the quark sector. The Cabibbo mixing between the first two generations of quarks can be generated by type D groups. Since all the finite subgroups of U (3 ) that are not the subgroups of S U (3 ) have not been classified, an exhaustive scan over all finite discrete groups up to order 2000 is performed with the help of the computer algebra system gap. We find that only 90 (10) groups for Dirac (Majorana) neutrinos can generate the lepton mixing angles in the experimentally preferred ranges. The lepton mixing matrix is still the trimaximal pattern and the Dirac C P phase remains trivial. The smallest groups that lead to viable mixing angles are [162, 10], [162, 12], and [162, 14]. For quark flavor mixing, the correct order of magnitude of the Cabibbo-Kobayashi-Maskawa matrix elements cannot be generated. Only the Cabibbo mixing is allowed even if we impose very loose constraints 0.1 ≤|Vu s|≤0.3 and |Vu b|≤|Vc b|<|Vu s|. The group Δ (6 ×72) can predict a Cabibbo angle θq=π /14 in good agreement with the best fit value. The observed Cabibbo mixing angle can easily be accommodated if the first two left-handed quark fields are assigned to a doublet. The groups that can give rise to both phenomenologically viable lepton mixing angles and acceptable Cabibbo angles are discussed, and the groups Δ (6 ×92), [648, 259], [648, 260], [648, 266], and Δ (6 ×142) are especially promising in the case of the triplet assignment for both quark and lepton sectors. The three groups [496, 19], [496, 21], and [496, 23] are interesting
CKM angle γ measurements at LHCb
NASA Astrophysics Data System (ADS)
Vallier, Alexis
2014-11-01
The CKM angle γ remains the least known parameter of the CKM mixing matrix. The precise measurement of this angle, as a Standard Model benchmark, is a key goal of the LHCb experiment. We present four recent CP violation studies related to the measurement of γ, including amplitude analysis of B± → DK± decays, the ADS/GLW analysis of B± → DK*0 decays and the time-dependent analysis of B± → DK±sK± decays.
Quark flavor mixing, CP violation, and all that
Gilman, F.J.
1988-04-01
We review the present state of knowledge of the mixing of quark flavors under weak interactions and the associated explanation of CP violation inherent in the single nontrivial phase present in the three-generation mixing matrix. In this context we present the phenomenological basis for the increasing possibility that large CP violation asymmetries can be experimentally observed in the B meson system. 39 refs., 11 figs.,
Flavor mixing with quarks and leptons
Bigi, I.I.
1987-10-01
The last year has brought such a wealth of new information on heavy flavors that meaningful bounds can now be placed on all fermion mass related parameters in the Standard Model. The status of the KM matrix is reviewed with particular emphasis on the theoretical uncertainties. B/sup 0/-anti B/sup 0/ mixing is reevaluated and CP violation is discussed as it is observed in K/sub L/ decays and as it hopefully can be studied in B decays. The report is concluded with short remarks on neutrino oscillations.
Phenomenology of the CKM (Cabibbo-Kobayashi-Maskawa) matrix
Nir, Y.
1989-07-01
The way in which an exact determination of the CKM matrix elements tests the Standard Model is demonstrated by a two generation example. The determination of matrix elements from meson semi-leptonic decays is explained, with an emphasis on the respective reliability of quark level and meson level calculations. The assumptions involved in the use of loop processes are described. Finally, the state of the art of our knowledge of the CKM matrix is presented. 19 refs., 2 figs.
Precise test of the unitarity of the CKM matrix via superallowed nuclear beta decay
NASA Astrophysics Data System (ADS)
Park, Hyo-In
2016-03-01
Superallowed 0+ --> 0+ nuclear beta decay between isospin T = 1 analogue states is a sensitive probe for studying the fundamental properties of the weak interaction. Today, the most precise measurements of the decay strengths (or ft values) of fourteen superallowed transitions, ranging from 10C to 74Rb, provide a direct determination of the vector coupling constant GV, and lead to the most precise value of Vud, the up-down quark-mixing element of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. When Vud is combined with the other top-row elements, Vus and Vub, the sum of squares of the top-row elements of the CKM matrix satisfies the unitarity condition at the level of +/-0.06%. The impact of this result on searches for new physics beyond the Standard Model motivates further work to improve even further the precision of the CKM-matrix unitarity sum. Our current focus is on measurements to constrain the uncertainty in calculations of the isospin-symmetry-breaking corrections needed to determine Vud from the experimental data. This can be achieved with high-precision comparisons of the ft values from four pairs of accessible mirror superallowed decays with A <= 42 . This presentation reports our results for the mass-38 pair, 38Ca --> 38mK and 38mK --> 38Ar, and our progress on measuring 42Ti decay. The measured ratio of the mirror ft values for A = 38 agrees well with the corrections currently used, and points the way to even tighter constraints on the unitarity of the CKM matrix. If the three mirror pairs, with A = 26 , A = 34 and A = 42 confirm and strengthen our present conclusion, it will become possible to shrink the systematic uncertainty on Vud, reduce the uncertainty on the CKM-matrix unitarity sum, and further constrain the scope for possible extensions to the Standard Model.
Larana, Bruno Casal
2010-01-01
The establishment of the electroweak single top quark production at CDF is experimentally challenging. The small single top signal hidden under large uncertain background processes makes it necessary an excellent understanding of the detector and a detailed study of the processes involved. Moreover, simple counting experiments are not sufficient to extract enough information from the candidate event sample and multivariate analysis techniques are crucial to distinguish signal from background. This thesis presents the world’s most sensitive individual search, together with CDF’s Neural Network analysis, for the combined s- and t-channel single top production. This analysis uses a dataset that corresponds to an integrated luminosity of 3.2fb^{-1}, and is based on a Boosted Decision Tree method that combines information from several input variables to construct a final powerful discriminant, reaching a sensitivity to the combined single top quark production equivalent to 5.2σ. The measured combined single top quark production cross section is 2.1^{+0.7} _{-0.6} pb assuming a top quark mass of 175 GeV/c^{2}. The probability that this result comes from a background-only fluctuation (p-value) is 0.0002, which corresponds to 3.5σ.
Study of 14O as a test of the unitarity of the CKM matrix and the CVC hypothesis
Burke, Jason Timothy
2004-06-01
The study of superallowed beta decay in nuclei, in conjunction with other experiments, provide a test of the unitarity of the quark mixing matrix or CKM matrix. Nonunitarity of the CKM matrix could imply the existence of a fourth generation of quarks, right handed currents in the weak interaction, and/or new exotic fermions. Advances in radioactive beam techniques allow the creation of nearly pure samples of nuclei for beta decay studies. The subject of this thesis is the development of a radioactive beam of 14O and the study of the 14O halflife and branching ratio. The radioactive beam is produced by ionizing 12C14O radioactive gas and then accelerating with an ECR ion source. The 14O nucleus decays via superallowed beta decay with a branching ratio > 99 percent. The low Z of 14O is important for calculating reliable corrections to the beta decay that generally increase in with Z. The > 99 percent branching ratio can be established with modest precision on the complementary branching ratio.When this work began the experimentally determined CKM matrix was nonunitary by 2.5 standard deviations. Recent studies of Kaon, Hyperon, and B meson decays have been used to determine Vus and Vub matrix elements. In this work the halflife and branching ratio of 14O are measured and used to establish Vud. The unitarity of the CKM matrix is then assessed. The halflife of 14O was determined to be 70.683 +- 0.015 s and the GamowTeller branching ratio was found to be 0.643 +- 0.020 percent. Using these results the value of Vud is 0.9738 +- 0.0005. Incorporating the new values for Vus of 0.2272 +- 0.0030 and Vub of 0.0035 +- 0.0015 the squared sum of the first row of the CKM matrix is 0.9999 +- 0.0017 which is consistent with unitarity.
Renormalization group equations for the CKM matrix
Kielanowski, P.; Juarez W, S. R.; Montes de Oca Y, J. H.
2008-12-01
We derive the one loop renormalization group equations for the Cabibbo-Kobayashi-Maskawa (CKM) matrix for the standard model, its two Higgs extension, and the minimal supersymmetric extension in a novel way. The derived equations depend only on a subset of the model parameters of the renormalization group equations for the quark Yukawa couplings so the CKM matrix evolution cannot fully test the renormalization group evolution of the quark Yukawa couplings. From the derived equations we obtain the invariant of the renormalization group evolution for three models which is the angle {phi}{sub 2} of the unitarity triangle. For the special case of the standard model and its extensions with v{sub 1}{approx_equal}v{sub 2} we demonstrate that also the shape of the unitarity triangle and the Buras-Wolfenstein parameters {rho} and {eta} are conserved. The invariance of the angles of the unitarity triangle means that it is not possible to find a model in which the CKM matrix might have a simple, special form at asymptotic energies.
Full CKM matrix with lattice QCD
Okamoto, Masataka; /Fermilab
2004-12-01
The authors show that it is now possible to fully determine the CKM matrix, for the first time, using lattice QCD. |V{sub cd}|, |V{sub cs}|, |V{sub ub}|, |V{sub cb}| and |V{sub us}| are, respectively, directly determined with the lattice results for form factors of semileptonic D {yields} {pi}lv, D {yields} Klv, B {yields} {pi}lv, B {yields} Dlv and K {yields} {pi}lv decays. The error from the quenched approximation is removed by using the MILC unquenced lattice gauge configurations, where the effect of u, d and s quarks is included. The error from the ''chiral'' extrapolation (m{sub l} {yields} m{sub ud}) is greatly reduced by using improved staggered quarks. The accuracy is comparable to that of the Particle Data Group averages. In addition, |V{sub ud}|, |V{sub ts}|, |V{sub ts}| and |V{sub td}| are determined by using unitarity of the CKM matrix and the experimental result for sin (2{beta}). In this way, they obtain all 9 CKM matrix elements, where the only theoretical input is lattice QCD. They also obtain all the Wolfenstein parameters, for the first time, using lattice QCD.
Quark and lepton masses and mixing in the landscape
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.
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.
Hogan H. Nguyen
2002-10-25
I describe the CKM experiment, a new initiative using the Fermilab Main Injector to obtain {approx} 100 events of the ultra-rare decay mode K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}. The branching ratio will be used to extract |V*{sub ts}V{sub td}|. Due to the decay mode's theoretical cleanliness, it plays a key role in over-constraining the Standard Model description of CP violation.
A crystalline quark-hadron mixed phase in neutron stars
NASA Astrophysics Data System (ADS)
Glendenning, N. K.
1994-08-01
The mixed phase of a substance undergoing a first order phase transition has entirely different behavior according as the substance has more than one conserved charge or only one, as in the text book examples. In the latter case the pressure and nature of the phases are constants throughout the coexistence phase. For systems with more than one conserved charge (or independent component) we prove two theorems: (1) The pressure and the nature of the phases in equilibrium change continuously as the proportion of the phases varies from one pure phase to the other. (2) If one of the conserved charges is the Coulomb force, an intermediate-range order will be created by the competition between Coulomb and surface interface energy. Their sum is minimized when the coexistence phase assumes a Coulomb lattice of one phase immersed in the other. The geometry will vary continuously as the proportion of phases. We illustrate the theorems for a simple description of the hadron to quark phase transition in neutron stars and find a crystalline phase many kilometers thick. However the theorems are general and pertain to chemical mixtures, nuclear systems, either static as in stars or dynamic as in collisions, and have possible application to phase transitions in the early universe.
A crystalline quark-hadron mixed phase in neutron stars
Glendenning, N.K.
1994-08-31
The mixed phase of a substance undergoing a first order phase transition has entirely different behavior according as the substance has more than one conserved charge or only one, as in the text book examples. In the latter case the pressure and nature of the phases are constants throughout the coexistence phase. For systems with more than one conserved charge (or independent component) we prove two theorems: (1) The pressure and the nature of the phases in equilibrium change continuously as the proportion of the phases varies from one pure phase to the other. (2) If one of the conserved charges is the Coulomb force, an intermediate-range order will be created by the competition between Coulomb and surface interface energy. Their sum is minimized when the coexistence phase assumes a Coulomb lattice of one phase immersed in the other. The geometry will vary continuously as the proportion of phases. We illustrate the theorems for a simple description of the hadron to quark phase transition in neutron stars and find a crystalline phase many kilometers thick. However the theorems are general and pertain to chemical mixtures, nuclear systems, either static as in stars or dynamic as in collisions, and have possible application to phase transitions in the early universe.
The Cabibbo angle as a universal seed for quark and lepton mixings
NASA Astrophysics Data System (ADS)
Roy, S.; Morisi, S.; Singh, N. N.; Valle, J. W. F.
2015-09-01
A model-independent ansatz to describe lepton and quark mixing in a unified way is suggested based upon the Cabibbo angle. In our framework neutrinos mix in a "Bi-Large" fashion, while the charged leptons mix as the "down-type" quarks do. In addition to the standard Wolfenstein parameters (λ, A) two other free parameters (ψ, δ) are needed to specify the physical lepton mixing matrix. Through this simple assumption one makes specific predictions for the atmospheric angle as well as leptonic CP violation in good agreement with current observations.
Partial Quark-Lepton Universality and Neutrino CP Violation
Liao, Jiajun; Marfatia, D.; Whisnant, K.
2015-01-01
We smore » tudy a model with partial quark-lepton universality that can naturally arise in grand unified theories. We find that constraints on the model can be reduced to a single condition on the Dirac CP phase δ in the neutrino sector. Using our current knowledge of the CKM and PMNS mixing matrices, we predict - 32 . 4 ° ≤ δ ≤ 32 . 0 ° at 2 σ .« less
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.
Neutral B-meson mixing from unquenched lattice QCD with domain-wall light quarks and static b quarks
Albertus, C.; Flynn, J. M.; Sachrajda, C. T.; Aoki, Y.; Ishikawa, T.; Boyle, P. A.; Wennekers, J.; Christ, N. H.; Dumitrescu, T. T.; Loktik, O.; Izubuchi, T.; Soni, A.; Van de Water, R. S.; Witzel, O.
2010-07-01
We demonstrate a method for calculating the neutral B-meson decay constants and mixing matrix elements in unquenched lattice QCD with domain-wall light quarks and static b-quarks. Our computation is performed on the '2+1' flavor gauge configurations generated by the RBC and UKQCD Collaborations with a lattice spacing of a{approx_equal}0.11 fm (a{sup -1}=1.729 GeV) and a lattice spatial volume of approximately (1.8 fm){sup 3}. We simulate at three different light sea quark masses with pion masses down to approximately 430 MeV, and extrapolate to the physical quark masses using a phenomenologically-motivated fit function based on next-to-leading order heavy-light meson SU(2) chiral perturbation theory. For the b-quarks, we use an improved formulation of the Eichten-Hill action with static link-smearing to increase the signal-to-noise ratio. We also improve the heavy-light axial current used to compute the B-meson decay constant to O({alpha}{sub s}pa) using one-loop lattice perturbation theory. We present initial results for the SU(3)-breaking ratios f{sub B{sub s}}/f{sub B{sub d}} and {xi}=f{sub B{sub s{radical}}}(B{sub B{sub s}})/f{sub B{sub d{radical}}}(B{sub B{sub d}}), thereby demonstrating the viability of the method. For the ratio of decay constants, we find f{sub B{sub s}}/f{sub B{sub d}}=1.15(12) and for the ratio of mixing matrix elements, we find {xi}=1.13(12), where in both cases the errors reflect the combined statistical and systematic uncertainties, including an estimate of the size of neglected O(1/m{sub b}) effects.
M. Battaglia et al.
2004-04-02
This report contains the results of the Workshop on the CKM Unitarity Triangle that was held at CERN on 13-16 February 2002. There had been several Workshops on B physics that concentrated on studies at e{sup +}e{sup -} machines, at the Tevatron, or at LHC separately. Here we brought together experts of different fields, both theorists and experimentalists, to study the determination of the CKM matrix from all the available data of K, D, and B physics. The analysis of LEP data for B physics is reaching its end, and one of the goals of the Workshop was to underline the results that have been achieved at LEP, SLC, and CESR. Another goal was to prepare for the transfer of responsibility for averaging B physics properties, that has developed within the LEP community, to the present main actors of these studies, from the B factory and the Tevatron experiments. The optimal way to combine the various experimental and theoretical inputs and to fit for the apex of the Unitarity Triangle has been a contentious issue. A further goal of the Workshop was to bring together the proponents of different fitting strategies, and to compare their approaches when applied to the same inputs. Since lattice QCD plays a very important role in the determination of the non-perturbative parameters needed to constrain the CKM unitarity triangle, the first Workshop was seen as an excellent opportunity to bring together lattice theorists with the aim of establishing a working group to compile averages for phenomenologically relevant quantities. Representatives from lattice collaborations around the world were invited to attend a meeting during the Workshop. A consensus was reached to set up three test working groups, collectively known as the ''CKM Lattice Working Group'', to review a number of well-studied quantities: quark masses, the kaon B-parameter, and the matrix elements relevant for neutral B-meson mixing. This report is organized as a coherent document with chapters covering the domains
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.
Neutrino emissivity in the quark-hadron mixed phase of neutron stars
NASA Astrophysics Data System (ADS)
Spinella, William M.; Weber, Fridolin; Contrera, Gustavo A.; Orsaria, Milva G.
2016-03-01
Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures (lesssim10^9 K) and quark fractions (lesssim 30% , and that contributions due to lattice vibrations are insignificant compared to static-lattice contributions.
Mixed heavy quark hybrid mesons, decay puzzles, and RHIC
Kisslinger, Leonard S.
2009-06-01
We estimate the energy of the lowest charmonium and upsilon states with hybrid admixtures using the method of QCD sum rules. Our results show that the {psi}{sup '}(2S) and {upsilon}(3S) states both have about a 50% admixture of hybrid and meson components. From this we find explanations of both the famous {rho}-{pi} puzzle for charmonium and the unusual pattern of {sigma} decays that have been found in {upsilon} decays. Moreover, this picture can be used for predictions of heavy quark production with the octet model for RHIC.
Simplified renormalizable T' model for tribimaximal mixing and Cabibbo angle
NASA Astrophysics Data System (ADS)
Frampton, Paul H.; Kephart, Thomas W.; Matsuzaki, Shinya
2008-10-01
In a simplified renormalizable model where the neutrinos have Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixings tan2θ12=(1)/(2), θ13=0, θ23=π/4 and with flavor symmetry T' there is a corresponding prediction where the quarks have Cabibbo-Kobayashi-Maskawa (CKM) mixings tan2Θ12=(2)/(3), Θ13=0, Θ23=0.
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.
Symmetry energy effects on the mixed hadron-quark phase at high baryon density
Di Toro, M.; Greco, V.; Plumari, S.; Liu, B.; Baran, V.; Colonna, M.
2011-01-15
The phase transition of hadronic to quark matter at high baryon and isospin density is analyzed. Relativistic mean-field models are used to describe hadronic matter, and the MIT bag model is adopted for quark matter. The boundaries of the mixed phase and the related critical points for symmetric and asymmetric matter are obtained. Due to the different symmetry term in the two phases, isospin effects appear to be rather significant. With increasing isospin asymmetry the binodal transition line of the (T,{rho}{sub B}) diagram is lowered to a region accessible through heavy-ion collisions in the energy range of the new planned facilities (e.g., the FAIR/NICA projects). Some observable effects are suggested, in particular an isospin distillation mechanism with a more isospin asymmetric quark phase, to be seen in charged meson yield ratios, and an onset of quark number scaling of the meson-baryon elliptic flows. The presented isospin effects on the mixed phase appear to be robust with respect to even large variations of the poorly known symmetry term at high baryon density in the hadron phase. The dependence of the results on a suitable treatment of isospin contributions in effective QCD Lagrangian approaches, at the level of explicit isovector parts and/or quark condensates, is discussed.
{rho}-{omega} mixing self-energy and model quark-gluon dynamics
Roberts, C.D.; Mitchell, K.L.; Tandy, P.C.; Cahill, R.T.
1995-08-01
The u-d quark-loop vacuum polarization process that mixes the {omega} and {rho} mesons and its contribution to the Charge-Symmetry-Breaking (CSB) piece of the nucleon-nucleon (NN) interaction has been studied in a QCD-based, model field theory: the Global Color-symmetry Model (GCM), using a confining quark propagator obtained in earlier studies. In fitting NN phase shifts it was found necessary to include a term in the NN potential that has, conventionally, been attributed to the mixing between {omega} and {rho} mesons that arises because of isospin asymmetry at the quark level, as manifest in the small u-d current-quark-mass difference. To the present, this term was modeled and assumed to be momentum independent. It is important to understand this term in the context of QCD. The results of this study indicate that the modification of the meson propagators produced by the quark loop is alone not sufficient to account for the observed charge symmetry breaking effects in the NN interaction. We are exploring other possible mechanisms which may describe the origin of CSB in the NN interaction.
Binary icosahedral flavor symmetry for four generations of quarks and leptons
NASA Astrophysics Data System (ADS)
Chen, Chian-Shu; Kephart, Thomas W.; Yuan, Tzu-Chiang
2013-10-01
To include the quark sector, the A5≡ I (icosahedron) four generation lepton model is extended to a binary icosahedral symmetry I' flavor model. We find that the masses of fermions, including the heavy sectors, can be accommodated. At leading order the Cabibbo-Kobayashi-Maskawa (CKM) matrix is the identity and the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix, resulting from the same set of vacua, corresponds to tribimaximal mixings.
Octet baryon magnetic moments in the chiral quark model with configuration mixing
Linde, J.; Ohlsson, T.; Snellman, H.
1998-01-01
The Coleman{endash}Glashow sum-rule for magnetic moments is always fulfilled in the chiral quark model, independently of SU(3) symmetry breaking. This is due to the structure of the wave functions, coming from the non-relativistic quark model. Experimentally, the Coleman{endash}Glashow sum-rule is violated by about ten standard deviations. To overcome this problem, two models of wave functions with configuration mixing are studied. One of these models violates the Coleman{endash}Glashow sum-rule to the right degree and also reproduces the octet baryon magnetic moments rather accurately. {copyright} {ital 1997} {ital The American Physical Society}
Niyogi, S. )
1991-09-07
The authors of this paper estimate the size of {eta}--{eta}{prime}, {eta}--{pi}{sup 0} and {eta}{prime}--{pi}{sup 0} mixing angles by solving the Ward-identities in QCD and taking into account SU(3) violation of the quark condensates. Our results are compared with those obtained by treating the quark condensates SU(3) symmetric.
Branz, Tanja; Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E.; Oexl, Bettina; Ivanov, Mikhail A.; Koerner, Juergen G.
2010-06-01
We study flavor-conserving radiative decays of double-heavy baryons using a manifestly Lorentz covariant constituent three-quark model. Decay rates are calculated and compared to each other in the full theory, keeping masses finite, and also in the heavy quark limit. We discuss in some detail hyperfine mixing effects.
Schwartz, Alan
2014-12-02
The Seventh International Workshop on the CKM Unitarity Triangle (http://ckm2012.uc.edu/) was held at the University of Cincinnati September 28-October 2, 2012. This workshop series is one of the leading meetings in the field of quark flavor physics. The Cincinnati workshop provided a venue for theorists and experimentalists to discuss the latest results and to develop new ideas for improved analyses. The most recent measurements from current experiments as well as the status of future experiments were discussed. On the theoretical side, progress in lattice QCD and other calculational techniques that allow more precise determinations of CKM matrix elements were presented.
CKM matrix and flavor symmetries
NASA Astrophysics Data System (ADS)
Araki, Takeshi; Ishida, Hiroyuki; Ishimori, Hajime; Kobayashi, Tatsuo; Ogasahara, Atsushi
2013-11-01
Following the way proposed recently by Hernandez and Smirnov, we seek possible residual symmetries in the quark sector with a focus on the von Dyck groups. We begin with two extreme cases in which both θ13 and θ23 or only θ13 are set to zero. Then, cases where all the Cabibbo-Kobayashi-Maskawa parameters are allowed to take nonzero values are explored. The Z7 symmetry is favorable to realize only the Cabibbo angle. On the other hand, larger groups are necessary in order to be consistent with all the mixing parameters. Possibilities of embedding the obtained residual symmetries into the Δ(6N2) series are also briefly discussed.
Simplified renormalizable T{sup '} model for tribimaximal mixing and Cabibbo angle
Frampton, Paul H.; Matsuzaki, Shinya; Kephart, Thomas W.
2008-10-01
In a simplified renormalizable model where the neutrinos have Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixings tan{sup 2}{theta}{sub 12}=(1/2), {theta}{sub 13}=0, {theta}{sub 23}={pi}/4 and with flavor symmetry T{sup '} there is a corresponding prediction where the quarks have Cabibbo-Kobayashi-Maskawa (CKM) mixings tan2{theta}{sub 12}=({radical}(2)/3), {theta}{sub 13}=0, {theta}{sub 23}=0.
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.
Fermion masses and mixing in Δ (27 ) flavor model
NASA Astrophysics Data System (ADS)
Abbas, Mohammed; Khalil, Shaaban
2015-03-01
An extension of the Standard Model (SM) based on the non-Abelian discrete group Δ (27 ) is considered. The Δ (27 ) flavor symmetry is spontaneously broken only by gauge singlet scalar fields, therefore our model is free from any flavor changing neutral current (FCNC). We show that the model accounts simultaneously for the observed quark and lepton masses and their mixing. In the quark sector, we find that the up-quark mass matrix is flavor diagonal and the Cabbibo-Kobayashi-Maskawa (CKM) mixing matrix arises from down quarks. In the lepton sector, we show that the charged lepton mass matrix is almost diagonal. We also adopt type-I seesaw mechanism to generate neutrino masses. A deviated mixing matrix from tri-bimaximal Maki-Nakagawa-Sakata (MNS), with a correlation between sin θ13 and sin2θ23 are illustrated.
Determination of the CKM Element V(Ub)
Fortin, Dominique; /Victoria U.
2007-04-06
The precise determination of the CKM matrix element |V{sub ub}| is crucial in testing the Standard Model mechanism for CP violation. From a sample of 88 million B{bar B} pairs collected with the BABAR detector, charmless semileptonic B decays are selected using simultaneous requirements on the electron energy, E{sub e}, and the invariant mass squared of the electron-neutrino pair, q{sup 2}. The partial branching fraction, unfolded for detector effects, is determined in a region of the q{sup 2}-E{sub e} plane where the dominating semileptonic decays to charm mesons are highly suppressed. Theoretical calculations based on the Heavy Quark Expanion allows for a determination of |V{sub ub}| = (3.95 {+-} 0.27{sub -0.42}{sup +0.58} {+-} 0.25) x 10{sup -3}, where the errors represent experimental, heavy quark parameters and theoretical uncertainties, respectively.
η ‑ η‧ mixing and decays of mesons with heavy quarks
NASA Astrophysics Data System (ADS)
Balitsky, Jaroslav V.; Kiselev, Valery V.; Likhoded, Anatoly K.; Samoylenko, Vladimir D.
2016-06-01
The inclusion of elastic rescattering and annihilation of quark-antiquarks pairs in final state can explain the t-dependency for cross-section ratio of η and η‧ mesons in charge exchange reaction. The estimation for mixing angle η ‑ η‧ with isoscalar states ūu + d¯d and hidden strangeness s¯s has been obtained. The consistent description of η and η‧ meson outputs in B0, Bs0 and J/ψ decays was also considered.
Discovery of single top quark production
Gillberg, Dag
2009-04-01
The top quark is by far the heaviest known fundamental particle with a mass nearing that of a gold atom. Because of this strikingly high mass, the top quark has several unique properties and might play an important role in electroweak symmetry breaking - the mechanism that gives all elementary particles mass. Creating top quarks requires access to very high energy collisions, and at present only the Tevatron collider at Fermilab is capable of reaching these energies. Until now, top quarks have only been observed produced in pairs via the strong interaction. At hadron colliders, it should also be possible to produce single top quarks via the electroweak interaction. Studies of single top quark production provide opportunities to measure the top quark spin, how top quarks mix with other quarks, and to look for new physics beyond the standard model. Because of these interesting properties, scientists have been looking for single top quarks for more than 15 years. This thesis presents the first discovery of single top quark production. An analysis is performed using 2.3 fb^{-1} of data recorded by the D0 detector at the Fermilab Tevatron Collider at centre-of-mass energy √s = 1.96 TeV. Boosted decision trees are used to isolate the single top signal from background, and the single top cross section is measured to be σ(p$\\bar{p}$ → tb + X, tqb + X) = 3.74_{-0.74}^{+0.95} pb. Using the same analysis, a measurement of the amplitude of the CKM matrix element V_{tb}, governing how top and b quarks mix, is also performed. The measurement yields: |V{sub tb}|f_{1}^{L}| = 1.05 -_{0.12}^{+0.13}, where f_{1}^{L} is the left-handed Wtb coupling. The separation of signal from background is improved by combining the boosted decision trees with two other multivariate techniques. A new cross section measurement is performed, and the significance for the excess over the predicted background exceeds 5
Khachatryan, Vardan
2014-06-16
Our measurements are presented of the t-channel single-top-quark production cross section in proton-proton collisions at √s = 8 TeV. The results are based on a data sample corresponding to an integrated luminosity of 19.7 fb^{-1} recorded with the CMS detector at the LHC. The cross section is measured inclusively, as well as separately for top (t) and antitop (t¯), in final states with a muon or an electron. The measured inclusive t-channel cross section is σ _{t-ch.} = 83.6 ± 2.3 (stat.) ± 7.4 (syst.) pb. The single t and t¯ cross sections are measured to be σ _{t-ch.}(t) = 53.8 ± 1.5 (stat.) ± 4.4 (syst.) pb and σ _{t-ch.} (t¯) = 27.6 ± 1.3 (stat.) ± 3.7 (syst.) pb, respectively. The measured ratio of cross sections is R_{ t-ch.} = σ _{t-ch.}(t)/σ _{t-ch.} (t¯) = 1.95 ± 0.10 (stat.) ± 0.19 (syst.), in agreement with the standard model prediction. Finally, the modulus of the Cabibbo-Kobayashi-Maskawa matrix element V _{tb} is extracted and, in combination with a previous CMS result at √s = 7 TeV, a value |V_{ tb}| = 0.998 ± 0.038 (exp.) ± 0.016 (theo.) is obtained.
Khachatryan, Vardan
2014-06-16
Our measurements are presented of the t-channel single-top-quark production cross section in proton-proton collisions at √s = 8 TeV. The results are based on a data sample corresponding to an integrated luminosity of 19.7 fb-1 recorded with the CMS detector at the LHC. The cross section is measured inclusively, as well as separately for top (t) and antitop (t¯), in final states with a muon or an electron. The measured inclusive t-channel cross section is σ t-ch. = 83.6 ± 2.3 (stat.) ± 7.4 (syst.) pb. The single t and t¯ cross sections are measured to be σ t-ch.(t) =more » 53.8 ± 1.5 (stat.) ± 4.4 (syst.) pb and σ t-ch. (t¯) = 27.6 ± 1.3 (stat.) ± 3.7 (syst.) pb, respectively. The measured ratio of cross sections is R t-ch. = σ t-ch.(t)/σ t-ch. (t¯) = 1.95 ± 0.10 (stat.) ± 0.19 (syst.), in agreement with the standard model prediction. Finally, the modulus of the Cabibbo-Kobayashi-Maskawa matrix element V tb is extracted and, in combination with a previous CMS result at √s = 7 TeV, a value |V tb| = 0.998 ± 0.038 (exp.) ± 0.016 (theo.) is obtained.« less
Measurement of CKM-angle gamma with Charmed B0 Meson Decays
Baak, Max Arjen
2007-07-17
This thesis reports measurements of the time-dependent CP asymmetries in fully reconstructed B{sup 0} {yields} (D{sup (*){-+}} and B{sup 0} {yields} D{sup {-+}} {rho}{sup {+-}}) decays in approximately 232 million {Upsilon}(4S) {yields} B{bar B} events, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center in California, as published in Ref. [14]. The phenomenon of CP violation allows one to distinguish between matter and antimatter, and, as such, is one of the essential ingredients needed to explain the apparent abundance of matter over antimatter in the universe. The Standard Model describes the observed elementary particles in terms of three generations of quarks and leptons, as well as the weak, electromagnetic, and strong interactions between them. In the Standard Model, CP violation is incorporated in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, which describes the weak interactions between the quarks. The weak interactions between quarks are described by coupling constants that are functions of three real parameters and one irreducible complex phase. The magnitude of all CP violating effects in the Standard Model is related to this complex phase. The measurement of the CP violating phase of the CKM matrix is an important part of the present scientific program in particle physics. Violation of the CP symmetry manifests itself as a non-zero area of the Unitarity Triangle. The Unitarity Triangle needs to be overconstrained by experimental measurements in order to demonstrate that the CKM mechanism is the correct explanation of this phenomenon. No stringent measurement of the CKM-angle {gamma} is yet available.
Neutral B meson mixings and B meson decay constants with static heavy and domain-wall light quarks
NASA Astrophysics Data System (ADS)
Aoki, Yasumichi; Ishikawa, Tomomi; Izubuchi, Taku; Lehner, Christoph; Soni, Amarjit
2015-06-01
Neutral B meson mixing matrix elements and B meson decay constants are calculated. The static approximation is used for the b quark and the domain-wall fermion formalism is employed for light quarks. The calculations are carried out on 2 +1 -flavor dynamical ensembles generated by the RBC and UKQCD collaborations with lattice spacings of 0.086 fm (a-1˜2.3 GeV ) and 0.11 fm (1.7 GeV), and a fixed physical spatial volume of about (2.7 fm )3 . In the static quark action, link smearings are used to improve the signal-to-noise ratio. We employ two kinds of link smearings, HYP1 and HYP2, and their results are combined when taking the continuum limit. For the matching between the lattice and the continuum theory, one-loop perturbative O (a ) improvements are made to reduce discretization errors. As the most important quantity of this work, we obtain the SU(3) breaking ratio ξ =1.208 (60 ), where the error includes both the statistical and systematic errors. (The uncertainty from an infinite b -quark mass is not included.) We also find other neutral B meson mixing quantities, fB√{B^ B }=240 (22 ) MeV , fBs√{B^Bs}=290 (22 ) MeV , B^B=1.17 (22 ), B^Bs=1.22(13 ), and BB s/BB=1.028 (74 ), and the B meson decay constants fB=219 (17 ) MeV , fBs=264(19 ) MeV , and fB s/fB=1.193 (41 ) in the static limit of the b quark, which do not include an infinite b -quark mass uncertainty.
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
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.
Recent Results on the CKM Angle Alpha
Mihalyi, A.; /Wisconsin U., Madison
2005-10-18
The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).
Experimental Status of the CKM Angle β
NASA Astrophysics Data System (ADS)
Hirschauer, James F.
2009-12-01
We summarize measurements of the CKM angle β at the B-factories emphasizing a comparison of β measured in the B0→cc¯K(*)0 decay channels and βeff measured in b→qq¯s decay channels, such as B0→ωKS0, B0→η'K0, B0→π0KS0, and B0→S0KS0KS0.
The determination of V sub ud and a test of the unitarity of the quark mixing matrix
Rasche, G. ); Woolcock, W.S. . Research School of Physical Sciences)
1990-07-10
The significant violation of unitarity implied by recently published results for the elements V{sub ud}, V{sub us} and V{sub ub} of the first row of the quark mixing matrix is considered. A possible way out of the difficulty is described, which gives a different value of {vert bar}V{sub ud}{vert bar}. It involves close scrutiny of the calculated values of the nuclear isospin breaking correction {delta}{sub c} to the ft values for superallowed {beta} decays.
Single Top Quarks at the Tevatron
Heinson, Ann P.; /UC, Riverside
2008-09-01
After many years searching for electroweak production of top quarks, the Tevatron collider experiments have now moved from obtaining first evidence for single top quark production to an impressive array of measurements that test the standard model in several directions. This paper describes measurements of the single top quark cross sections, limits set on the CKM matrix element |Vtb|, searches for production of single top quarks produced via flavor-changing neutral currents and from heavy W-prime and H+ boson resonances, and studies of anomalous Wtb couplings. It concludes with projections for future expected significance as the analyzed datasets grow.
Neutrino mixing and masses in SO(10) GUTs with hidden sector and flavor symmetries
NASA Astrophysics Data System (ADS)
Chu, Xiaoyong; Smirnov, Alexei Yu.
2016-05-01
We consider the neutrino masses and mixing in the framework of SO(10) GUTs with hidden sector consisting of fermionic and bosonic SO(10) singlets and flavor symmetries. The framework allows to disentangle the CKM physics responsible for the CKM mixing and different mass hierarchies of quarks and leptons and the neutrino new physics which produces smallness of neutrino masses and large lepton mixing. The framework leads naturally to the relation U PMNS ˜ V CKM † U 0, where structure of U 0 is determined by the flavor symmetry. The key feature of the framework is that apart from the Dirac mass matrices m D , the portal mass matrix M D and the mass matrix of singlets M S are also involved in generation of the lepton mixing. This opens up new possibilities to realize the flavor symmetries and explain the data. Using A 4 × Z 4 as the flavor group, we systematically explore the flavor structures which can be obtained in this framework depending on field content and symmetry assignments. We formulate additional conditions which lead to U 0 ˜ U TBM or U BM. They include (i) equality (in general, proportionality) of the singlet flavons couplings, (ii) equality of their VEVs; (iii) correlation between VEVs of singlets and triplet, (iv) certain VEV alignment of flavon triplet(s). These features can follow from additional symmetries or be remnants of further unification. Phenomenologically viable schemes with minimal flavon content and minimal number of couplings are constructed.
NASA Astrophysics Data System (ADS)
Ke, Hong-Wei; Liu, Tan; Li, Xue-Qian
2014-09-01
It is suggested that there is an underlying symmetry which relates the quark and lepton sectors. Namely, among the mixing matrix elements of Cabibbo-Kobayashi-Maskawa for quarks and Pontecorvo-Maki-Nakawaga-Sakata for leptons there exist complementarity relations at a high energy scale (such as the seesaw or even the grand unification theory scales). We assume that the relations would remain during the matrix elements running down to the electroweak scale. Observable breaking of the rational relation is attributed to the existence of sterile neutrinos that mix with the active neutrino to result in the observable Pontecorvo-Maki-Nakawaga-Sakata matrix. We show that involvement of a sterile in the (3+1) model induces that |Ue4|2=0.040, |Uμ4|2=0.009, and sin22α =0.067. We also find a new self-complementarity ϑ12+ϑ23+ϑ13+α ≈90°. The numbers are generally consistent with those obtained by fitting recent measurements, especially in this scenario, to the existence of a sterile neutrino that does not upset the LEP data; i.e., the number of neutrino types is very close to 3.
COOLING OF COMPACT STARS WITH COLOR SUPERCONDUCTING PHASE IN QUARK-HADRON MIXED PHASE
Noda, Tsuneo; Hashimoto, Masa-aki; Yasutake, Nobutoshi; Maruyama, Toshiki; Tatsumi, Toshitaka; Fujimoto, Masayuki E-mail: hashimoto@phys.kyushu-u.ac.jp
2013-03-01
We present a new scenario for the cooling of compact stars considering the central source of Cassiopeia A (Cas A). The Cas A observation shows that the central source is a compact star that has high effective temperature, and it is consistent with the cooling without exotic phases. The observation also gives the mass range of M {>=} 1.5 M {sub Sun }, which may conflict with the current plausible cooling scenario of compact stars. There are some cooled compact stars such as Vela or 3C58, which can barely be explained by the minimal cooling scenario, which includes the neutrino emission by nucleon superfluidity (PBF). Therefore, we invoke the exotic cooling processes, where a heavier star cools faster than lighter one. However, the scenario seems to be inconsistent with the observation of Cas A. Therefore, we present a new cooling scenario to explain the observation of Cas A by constructing models that include a quark color superconducting (CSC) phase with a large energy gap; this phase appears at ultrahigh density regions and reduces neutrino emissivity. In our model, a compact star has a CSC quark core with a low neutrino emissivity surrounded by high emissivity region made by normal quarks. We present cooling curves obtained from the evolutionary calculations of compact stars: while heavier stars cool slowly, and lighter ones indicate the opposite tendency without considering nucleon superfluidity. Furthermore, we show that our scenario is consistent with the recent observations of the effective temperature of Cas A during the last 10 years, including nucleon superfluidity.
Lau, Yan-Pan
2007-07-10
Despite more than thirty years having elapsed since the discovery of CP violation, our understanding about the source and the nature of this phenomenon is still very limited. In the standard model of particle physics, CP violation is due to the presence of an non-irreducible weak phase in the Cabibbo-Kabayashi-Maskawa(CKM) matrix. Up to now, all the experimental results are in good agreement with the standard model. However, it is important for us to over-constrain the CKM quark-mixing matrix and explore the possibility of new physics beyond the standard model. The B meson provides an ideal place to measure CP violation due to its heavy mass and potentially large CP-violating effects. In particular, the angle {gamma} of the Unitary Triangle relating the elements of the CKM matrix is extremely crucial in terms of CP violation and constraints on the new physics models. Various methods using B{sup -} {yields} D{sup 0}K{sup -} decays have been proposed to measure based on the interference between the V{sub cb} and V{sub ub} amplitudes. Despite the simple concept, the measurement turns out to be experimentally challenging due to the small branching fraction and the small value of {tau}{sub B}, the amplitude ratio between the two contributing Feynman diagrams. In this thesis a novel technique to measure {gamma} in B{sup -} {yields} D{sup (*)} K{sup -} decay using a Dalitz plot analysis of D{sup 0} {yields} K{sub s}{pi}{sup +}{pi}{sup -} is presented. Until the turn on of LHC{sub b} [1] later in the decade, this remains the most promising method to measure {gamma}. This thesis is roughly separated into two parts. The first part involves a study of hadron spectroscopy and the Dalitz plot analysis of the D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -}. The second part of the thesis involves the measurement of {gamma} in B{sup -} {yields} D{sup (*)} K{sup -} using the results of the D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} dalitz plot analysis.
An Underlying Symmetry Determines all Elements of CKM and PMNS up to a Universal Constant?
NASA Astrophysics Data System (ADS)
Ke, Hong-Wei; Li, Xue-Qian
2015-11-01
Observing the CKM matrix elements written in different parametrization schemes, one can notice obvious relations among the sine-values of the CP phases in those schemes. Using the relations, we establish a few parametrization-independent equations, by which the matrix elements of the CKM matrix can be completely fixed up to a universal parameter. If it is true, we expect that there should exist a hidden symmetry in the nature, which determines the relations. Moreover, it requires a universal parameter, naturally it would be the famous Jarlskog invariant, which is also parametrization independent. Thus the four parameters (three mixing angles and one CP phase) of the CKM matrix are not free, but determined by the symmetry and the universal parameter. As we generalize the rules to the PMNS matrix for neutrino mixing, the CP phase of the lepton sector is predicted to be within a range of 0 ∼ 59° centered at 39° (in the Pa parametrization) which will be tested in the future experiments. Supported by the National Natural Science Foundation of China under Grant Nos. 11375128 and 11135009
B(s) 0-mixing matrix elements from lattice QCD for the Standard Model and beyond
NASA Astrophysics Data System (ADS)
Bazavov, A.; Bernard, C.; Bouchard, C. M.; Chang, C. C.; DeTar, C.; Du, Daping; El-Khadra, A. X.; Freeland, E. D.; Gámiz, E.; Gottlieb, Steven; Heller, U. M.; Kronfeld, A. S.; Laiho, J.; Mackenzie, P. B.; Neil, E. T.; Simone, J.; Sugar, R.; Toussaint, D.; Van de Water, R. S.; Zhou, Ran; Fermilab Lattice; MILC Collaborations
2016-06-01
We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B0- and Bs-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B -meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ =1.206 (18 )(6 ), where the second error stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrix elements to the physical point. We combine our results with experimental measurements of the neutral B -meson oscillation frequencies to determine the CKM matrix elements |Vt d|=8.00 (34 )(8 )×10-3, |Vt s|=39.0 (1.2 )(0.4 )×10-3, and |Vt d/Vt s|=0.2052 (31 )(10 ), which differ from CKM-unitarity expectations by about 2 σ . These results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.
Single top quark production and Vtb at the Tevatron
Schwienhorst, Reinhard; /Michigan State U.
2010-09-01
Single top quark production via the electroweak interaction was observed by the D0 and CDF collaborations at the Tevatron proton-antiproton collider at Fermilab. Multivariate analysis techniques are employed to extract the small single top quark signal. The combined Tevatron cross section is 2.76{sub -0.47}{sup +0.58} pb. This corresponds to a lower limit on the CKM matrix element |V{sub tb}| of 0.77. Also reported are measurements of the t-channel cross section, the top quark polarization in single top quark events, and limits on gluon-quark flavor-changing neutral currents and W{prime} boson production.
Experimental Status of the CKM Angle {beta}
Hirschauer, James F.
2009-12-17
We summarize measurements of the CKM angle {beta} at the B-factories emphasizing a comparison of {beta} measured in the B{sup 0}{yields}cc-barK{sup (*)0} decay channels and {beta}{sub eff} measured in b{yields}qq-bars decay channels, such as B{sup 0}{yields}{omega}K{sub S}{sup 0}, B{sup 0}{yields}{eta}'K{sup 0}, B{sup 0}{yields}{pi}{sup 0}K{sub S}{sup 0}, and B{sup 0}{yields}{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}.
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.
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.
Measurement of the CKM Angles at BaBar And Belle
Barlow, Nick; /Manchester U.
2007-12-05
The primary goal of the BaBar and Belle experiments is to overconstrain the CKM Unitarity Triangle. Measurements of the angles of this triangle, known as {beta}, {alpha}, and {gamma} (or {phi}{sub 1}, {phi}{sub 2}, and {phi}{sub 3}) give insight into the Standard Model description of CP violation in the quark sector. BaBar and Belle have recorded almost 1 ab{sup -1} combined, and have measured {beta} to high precision. Measurements of {alpha} and {gamma} are less precise at present, but both experiments are rapidly accumulating data and developing new analysis techniques, and measurements of these angles will continue to provide useful constraints on the Standard Model description of CP violation in the years to come.
Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Tico, J.Garra; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /Annecy, LAPP /Barcelona U., ECM /INFN, Bari /Bari U. /Bergen U. /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U.
2009-07-14
The authors present improved measurements of the branching fraction {Beta}, the longitudinal polarization fraction f{sub L}, and the direct CP asymmetry A{sub CP} in the B meson decay channel B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. The data sample was collected with the BABAR detector at SLAC. The results are {Beta}(B{sup +} {yields} {rho}{sup +}{rho}{sup 0}) = (23.7 {+-} 1.4 {+-} 1.4) x 10{sup -6}, f{sub L} = 0.950 {+-} 0.015 {+-} 0.006, and A{sub CP} = -0.054 {+-} 0.055 {+-} 0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, they perform an isospin analysis and determine the CKM weak phase angle {alpha} to be (92.4{sub -6.5}{sup +6.0}){sup 0}.
B{sub s(d)}-B{sub s(d)} mixing constraints on flavor changing decays of t and b quarks
Faessler, Amand; Gutsche, Thomas; Lyubovitskij, Valery E.; Kovalenko, Sergey; Schmidt, Ivan
2010-10-01
We study those dimension 6 effective operators which generate flavor-changing quark-gluon transitions of the third generation quarks, with t{yields}g+u(c) and b{yields}g+d(s), and which could be of interest for LHC experiments. We analyze the contribution of these operators to B{sub s(d)}-B{sub s(d)} mixing and derive limits on the corresponding effective couplings from the existing experimental data. The standard model gauge invariance relates these couplings to the couplings controlling t{yields}g+u(c). On this basis we derive upper limits for the branching ratios of these processes. We further show that forthcoming LHC experiments might be able to probe the studied operators and the physics beyond the standard model related to them.
Implications of equalities among the elements of CKM and PMNS matrices
NASA Astrophysics Data System (ADS)
Ke, Hong-Wei; Zhao, Song-Xue; Li, Xue-Qian
2016-05-01
Investigating the CKM matrix in different parameterization schemes, it is noticed that those schemes can be divided into a few groups where the sine values of the CP phase for each group are approximately equal i.e. there exist several relations among the CP phases. Using those relations, several approximate equalities among the elements of CKM matrix are established. The case can also be generalized to the PMNS matrix for the lepton sector. Assuming them to be exact, there are infinite numbers of solutions and by choosing special values for the free parameters in those solutions, several textures presented in the literature are obtained. Other authors have derived several mixing textures by using presumed symmetries; amazingly, some, though not all, of their forms are the same as those we obtained. This hints at the existence of a hidden symmetry which is broken in the practical world. Nature makes its own selection of the underlying symmetry and the way to break it, while we just guess what it is. Supported by National Natural Science Foundation of China (11375128, 11135009)
Stracka, Simone
2011-02-01
In the Standard Model, CP violation in weak interactions involving quarks is parameterized by an irreducible complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing-matrix. The precise determination of the CKM elements is a necessary ingredient for a stringent test of the Standard Model predictions, and is a crucial input for reducing the theoretical error in many New Physics searches with flavor, e.g., in the kaon sector. The unitarity of the CKM matrix is typically expressed as a triangle relationship among its parameters, where the area of the so-called Unitarity Triangle visually depicts the amount of asymmetry between the decays of B particles and their antimatter counterparts. In the past few years, the BABAR and Belle experiments have been able to measure all three angles of the triangle from CP asymmetry measurements. The first asymmetry measurements in B particle decays, about ten years ago, allowed to determine β, which is now known to better than 5% precision. The angles α and γ, measured in much rarer processes, required several years of data taking before analyses could yield reliable answers. A remarkable feature is that the direct measurement of the angles of the Unitarity Triangle generates an area that is consistent with the area predicted by measurement of the sides. In this thesis we have presented the branching fraction measurements of charged and neutral B meson decays to K_{1}(1270)π and K_{1}(1400)π, obtained from a data sample of 454 million Υ(4S) → B$\\bar{B}$ events. This analysis is particularly challenging from the experimental side since the branching fractions involved are very low, at the level of 10^{-6} - 10^{-7}, and the signal is characterized by the simultaneous presence of two overlapping resonances, which exhibit sizeable interference effects. The combined K_{1}(1270)π and K_{1}(1400)π signal is therefore modeled with a K-matrix formalism, which accounts for
Mixing and CP Violation in Charm Meson Decays
Meadows, B; /Cincinnati U.
2010-08-26
Mixing and CP violation (CPV ) in the neutral D system were first discussed over thirty years ago but mixing was observed for the first time only very recently. Since then, these observations have been confirmed in other experiments and in other D{sup 0} decay modes. Unlike the K, B and B{sub s} systems, for which mixing was observed years earlier, the short distance ({Delta}C = 2) amplitude contributing to mixing in the D system arises from box diagrams with down- rather than up-type quarks in the loops. The d and s components are GIM-suppressed, and the b component is suppressed by the small V{sub ub} CKM coupling. In the standard model (SM), therefore, long range, non-perturbative effects, a coherent sum over intermediate states accessible to both D{sup 0} and {bar D}{sup 0}, are the main contribution to mixing. These are hard to compute reliably, however. The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D{sup 0} system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation, either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
Origin of symmetric PMNS and CKM matrices
NASA Astrophysics Data System (ADS)
Rodejohann, Werner; Xu, Xun-Jie
2015-03-01
The Pontecorvo-Maki-Nakagawa-Sakata and Cabibbo-Kobayashi-Maskawa matrices are phenomenologically close to symmetric, and a symmetric form could be used as zeroth-order approximation for both matrices. We study the possible theoretical origin of this feature in flavor symmetry models. We identify necessary geometric properties of discrete flavor symmetry groups that can lead to symmetric mixing matrices. Those properties are actually very common in discrete groups such as A4 , S4 , or Δ (96 ) . As an application of our theorem, we generate a symmetric lepton mixing scheme with θ12=θ23=36.21 ° ; θ13=12.20 ° , and δ =0 , realized with the group Δ (96 ) .
$$B^0_{(s)}$$-mixing matrix elements from lattice QCD for the Standard Model and beyond
Bazavov, A.; Bernard, C.; Bouchard, C. M.; Chang, C. C.; DeTar, C.; Du, Daping; El-Khadra, A. X.; Freeland, E. D.; Gamiz, E.; Gottlieb, Steven; et al
2016-06-28
We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B0- and Bs-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B-meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ=1.206(18)(6), where the second errormore » stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrix elements to the physical point. We combine our results with experimental measurements of the neutral B-meson oscillation frequencies to determine the CKM matrix elements |Vtd| = 8.00(34)(8)×10-3, |Vts| = 39.0(1.2)(0.4)×10-3, and |Vtd/Vts| = 0.2052(31)(10), which differ from CKM-unitarity expectations by about 2σ. In addition, these results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.« less
SUSY SU(5)× S 4 GUT flavor model for fermion masses and mixings with adjoint, large θ 13 PMNS
NASA Astrophysics Data System (ADS)
Zhao, Ya; Zhang, Peng-Fei
2016-06-01
We propose an S 4 flavor model based on supersymmetric (SUSY) SU(5) GUT. The first and third generations of 10 dimensional representations in SU(5) are all assigned to be 11 of S 4. The second generation of 10 is to be 12 of S 4. Right-handed neutrinos of singlet 1 and three generations of overline{mathbf{5}} are all assigned to be 31 of S 4. The VEVs of two sets of flavon fields are allowed a moderate hierarchy, that is <Φ ν > ˜ λ c <Φ e >. Tri-Bimaximal (TBM) mixing can be produced at both leading order (LO) and next to next to leading order (NNLO) in neutrino sector. All the masses of up-type quarks are obtained at LO. We also get the bottom-tau unification m τ = m b and the popular Georgi-Jarlskog relation m μ = 3 m s as well as a new mass relation {m}_e=8/27{m}_d in which the novel Clebsch-Gordan (CG) factor arises from the adjoint field H 24. The GUT relation leads to a sizable mixing angle θ 12 e ˜ θ c and the correct quark mixing matrix V CKM can also be realised in the model. The resulting CKM-like mixing matrix of charged leptons modifies the vanishing θ 13 ν in TBM mixing to a large {θ}_{13}^{PMNS}˜eq {θ}_c/√{2} , in excellent agreement with experimental results. A Dirac CP violation phase ϕ 12 ≃ ±π /2 is required to make the deviation from θ 12 ν small. We also present some phenomenological numerical results predicted by the model.
Quark-lepton complementarity predictions for θ 23 pmns and CP violation
NASA Astrophysics Data System (ADS)
Sharma, Gazal; Chauhan, B. C.
2016-07-01
In the light of recent experimental results on θ 13 pmns , we re-investigate the complementarity between the quark and lepton mixing matrices and obtain predictions for most unsettled neutrino mixing parameters like θ 23 pmns and CP violating phase invariants J, S 1 and S 2. This paper is motivated by our previous work where in a QLC model we predicted the value for θ 13 pmns = (9 - 2 + 1 ) °, which was found to be in strong agreement with the experimental results. In the QLC model the non-trivial correlation between CKM and PMNS mixing matrices is given by a correlation matrix ( V c ). We do numerical simulation and estimate the texture of the V c and in our findings we get a small deviation from the Tri-Bi-Maximal (TBM) texture and a large from the Bi-Maximal one, which is consistent with the work already reported in literature. In the further investigation we obtain quite constrained limits for sin2 θ 23 pmns = 0. 4235 - 0.0043 + 0.0032 that is narrower to the existing ones. We also obtain the constrained limits for the three CP violating phase invariants J , S 1 and S 2:as J < 0 .0315, S 1 < 0 .12 and S 2 < 0 .08, respectively.
What do we know (and how) about the CKM (Cabibbo-Kobayashi-Maskawa) matrix
Nir, Y.
1989-05-01
The way from an experimental measurement to the numerical value for a CKM matrix element is described. How do we choose the appropriate model. What are the uncertainties involved. Where should we direct our future efforts. How do loop processes help us. Finally we describe the state of the art of our knowledge of the CKM matrix. 6 refs.
Lepton mixing from the hidden sector
NASA Astrophysics Data System (ADS)
Ludl, P. O.; Smirnov, A. Yu.
2015-10-01
Experimental results indicate a possible relation between the lepton and quark mixing matrices of the form UPMNS≈VCKM†UX , where UX is a matrix with special structure related to the mechanism of neutrino mass generation. We propose a framework which can realize such a relation. The main ingredients of the framework are the double seesaw mechanism, SO(10) grand unification and a hidden sector of theory. The latter is composed of singlets (fermions and bosons) of the grand unified theory (GUT) symmetry with masses between the GUT and Planck scale. The interactions in this sector obey certain symmetries Ghidden. We explore the conditions under which symmetries Ghidden can produce flavor structures in the visible sector. Here the key elements are the basis-fixing symmetry and mediators which communicate information about properties of the hidden sector to the visible one. The interplay of SO(10) symmetry, basis-fixing symmetry identified as Z2×Z2 and Ghidden can lead to the required form of UX. A different kind of new physics is responsible for generation of the CKM mixing. We present the simplest realizations of the framework which differ by nature of the mediators and by symmetries of the hidden sector.
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
Evolution of the CKM matrix in the universal extra dimension model
Cornell, A. S.; Liu Luxin
2011-02-01
The evolution of the Cabibbo-Kobayashi-Maskawa matrix and the quark Yukawa couplings is performed for the one-loop renormalization group equations in the universal extra dimension model. It is found that the evolution of mixing angles and the CP violation measure J may rapidly vary in the presence of the Kaluza-Klein modes, and this variation becomes dramatic as the energy approaches the unification scale.
The CKM matrix from anti-SU(7) unification of GUT families
NASA Astrophysics Data System (ADS)
Kim, Jihn E.; Mo, Doh Young; Seo, Min-Seok
2015-10-01
We estimate the CKM matrix elements in the recently proposed minimal model, anti-SU(7) GUT for the family unification, [ 3 ] + 2 [ 2 ] + 8 [ 1 bar ] +(singlets). It is shown that the real angles of the right-handed unitary matrix diagonalizing the mass matrix can be determined to fit the Particle Data Group data. However, the phase in the right-handed unitary matrix is not constrained very much. At present, there are three classes of possible CKM parametrizations, δCKM = α , β, or γ of the unitarity triangle. For the choice of δCKM = α, it is easy to show that the phase is close to a maximal one, which has a parametrization-independent meaning.
Measurement of the CKM Matrix Elements |Vcb| and |Vub| at the B-factories
Menges, Wolfgang
2006-08-01
Recent results on inclusive and exclusive semileptonic B decays from B-factories are presented. The impact of these measurements on the determination of the CKM matrix elements |V{sub ub}| and |V{sub cb}| is discussed.
Top quark properties and single top at CMS
NASA Astrophysics Data System (ADS)
Skovpenon, K.; CMS Collaboration
2016-07-01
Measurements of top-quark properties as well as single top-quark production are presented, obtained from the CMS data collected in 2011 and 2012 at centre-of-mass energies of 7 and 8TeV. The results include measurements of the top pair charge asymmetry, the W helicity in top decays, the t bar{{t}} spin correlation and the search for anomalous couplings. The cross sections for the electroweak production of single top quarks in the t-channel and in association with W-bosons are measured and the results are used to place constraints on the CKM matrix element Vtb. In the t-channel the ratio of top and antitop production cross sections is determined and compared with predictions from different parton density distribution functions. The results are compared with predictions from the standard model as well as new physics models.
Unexpected manifestation of quark condensation
Zinovjev, G. M.; Molodtsov, S. V.
2015-05-15
A comparative analysis of some quark ensembles governed by a four-fermion interaction is performed. Arguments in support of the statement that the presence of a gas-liquid phase transition is a feature peculiar to them are adduced. The instability of small quark droplets is discussed and is attributed to the formation of a chiral soliton. The stability of baryon matter is due to a mixed phase of the vacuum and baryon matter.
Measurements of the CKM Angle Alpha at BaBar
Stracka, Simone; /Milan U. /INFN, Milan
2012-04-04
The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.
Molecular Characterization and Expression Analysis of Creatine Kinase Muscle (CK-M) Gene in Horse.
Do, Kyong-Tak; Cho, Hyun-Woo; Badrinath, Narayanasamy; Park, Jeong-Woong; Choi, Jae-Young; Chung, Young-Hwa; Lee, Hak-Kyo; Song, Ki-Duk; Cho, Byung-Wook
2015-12-01
Since ancient days, domestic horses have been closely associated with human civilization. Today, horse racing is an important industry. Various genes involved in energy production and muscle contraction are differentially regulated during a race. Among them, creatine kinase (CK) is well known for its regulation of energy preservation in animal cells. CK is an iso-enzyme, encoded by different genes and expressed in skeletal muscle, heart, brain and leucocytes. We confirmed that the expression of CK-M significantly increased in the blood after a 30 minute exercise period, while no considerable change was observed in skeletal muscle. Analysis of various tissues showed an ubiquitous expression of the CK-M gene in the horse; CK-M mRNA expression was predominant in the skeletal muscle and the cardiac muscle compared to other tissues. An evolutionary study by synonymous and non-synonymous single nucleotide polymorphism ratio of CK-M gene revealed a positive selection that was conserved in the horse. More studies are warranted in order to develop the expression of CK-M gene as a biomarker in blood of thoroughbred horses. PMID:26580434
Molecular Characterization and Expression Analysis of Creatine Kinase Muscle (CK-M) Gene in Horse
Do, Kyong-Tak; Cho, Hyun-Woo; Badrinath, Narayanasamy; Park, Jeong-Woong; Choi, Jae-Young; Chung, Young-Hwa; Lee, Hak-Kyo; Song, Ki-Duk; Cho, Byung-Wook
2015-01-01
Since ancient days, domestic horses have been closely associated with human civilization. Today, horse racing is an important industry. Various genes involved in energy production and muscle contraction are differentially regulated during a race. Among them, creatine kinase (CK) is well known for its regulation of energy preservation in animal cells. CK is an iso-enzyme, encoded by different genes and expressed in skeletal muscle, heart, brain and leucocytes. We confirmed that the expression of CK-M significantly increased in the blood after a 30 minute exercise period, while no considerable change was observed in skeletal muscle. Analysis of various tissues showed an ubiquitous expression of the CK-M gene in the horse; CK-M mRNA expression was predominant in the skeletal muscle and the cardiac muscle compared to other tissues. An evolutionary study by synonymous and non-synonymous single nucleotide polymorphism ratio of CK-M gene revealed a positive selection that was conserved in the horse. More studies are warranted in order to develop the expression of CK-M gene as a biomarker in blood of thoroughbred horses. PMID:26580434
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.
Carrillo Moreno, Salvador; Vazquez Valencia, Elsa Fabiola
2006-09-25
This is a brief summary about the development of the charm quark physics in the area of experimental physics. The summary is centered in what is done by mexican physicists, particularly in the E791 and the FOCUS Experiment at FERMILAB. FOCUS (or E831) was designed to detect states of matter combining one or more charm quarks with light quarks (strange, up, down). The experiment created 10 times as many such particles as in previous experiments and investigated several topics on charm physics including high precision studies of charm semileptonic decays, studies of hadronic charm decays (branching ratios and Daltiz analyses), lifetime measurements of all charm particles, searches for mixing, CP/CPT violation, rare and forbidden decays, spectroscopy of excited charm mesons and baryons, charm production asymmetry measurements, light quark diffractive studies, QCD studies using charm pair events and searches for and upper limits on: charm pentaquarks, double charm baryons, DSJ(2632)
NASA Astrophysics Data System (ADS)
Chen, Yanjie; Zhang, Quanqi; Qi, Jie; Wang, Zhigang; Wang, Xubo; Sun, Yeying; Zhong, Qiwang; Li, Shuo; Li, Chunmei
2010-05-01
The symmetrical body of flatfish larvae changes dramatically into an asymmetrical form after metamorphosis. The molecular mechanisms responsible for this change are poorly understood. As an initial step to clarify these mechanisms, we used representational difference analysis of cDNA for the identification of genes active during metamorphosis in the Japanese flounder, Paralichthys olicaceus. One of the up-regulated genes was identified as creatine kinase muscle type 1 (CK-M1). Sequence analysis of CK-M1 revealed that it spanned 1 708 bp and encoded a protein of 382 amino acids. The overall amino acid sequence of the CK-M1 was highly conserved with those of other organisms. CK-M1 was expressed in adult fish tissues, including skeletal muscle, intestine and gill. Whole mount in-situ hybridization showed that the enhanced expression of CK-M1 expanded from the head to the whole body of larvae as metamorphosis progressed. Quantitative analysis revealed stage-specific high expression of CK-M1 during metamorphosis. The expression level of CK-M1 increased initially and peaked at metamorphosis, decreased afterward, and finally returned to the pre-metamorphosis level. This stage-specific expression pattern suggested strongly that CK-M1 was related to metamorphosis in the Japanese flounder. Its specific role in metamorphosis requires further study.
Current status of the standard model CKM fit and constraints on Δ F =2 new physics
NASA Astrophysics Data System (ADS)
Charles, J.; Deschamps, O.; Descotes-Genon, S.; Lacker, H.; Menzel, A.; Monteil, S.; Niess, V.; Ocariz, J.; Orloff, J.; Perez, A.; Qian, W.; Tisserand, V.; Trabelsi, K.; Urquijo, P.; Vale Silva, L.; CKMfitter Group
2015-04-01
This article summarizes the status of the global fit of the Cabibbo-Kobayashi-Maskawa (CKM) parameters within the Standard Model performed by the CKMfitter group. Special attention is paid to the inputs for the CKM angles α and γ and the status of Bs→μ μ and Bd→μ μ decays. We illustrate the current situation for other unitarity triangles. We also discuss the constraints on generic Δ F =2 new physics. All results have been obtained with the CKMfitter analysis package, featuring the frequentist statistical approach and using Rfit to handle theoretical uncertainties.
Tevatron combination of single top quark production and Vtb measurement
Lueck, J.; /Karlsruhe U., EKP
2010-11-01
After the first observation of the inclusive single top-quark production in the s- and t-channels by CDF and D0, both Tevatron collaborations combined their measurements using the distributions of their multivariate discriminants. A Bayesian analysis is used to extract the cross section at a center of mass energy of 1.96 TeV from 3.2 fb{sup -1} (CDF) and 2.3 fb{sup -1} (D0) of data, respectively. For a top quark mass of 170 GeV/c{sup 2}, a cross section of 2.76 + 0.58 - 0.47 pb is extracted while the CKM matrix element |V{sub tb}| is measured to be 0.88 {+-} 0.07 with a 95% C.L. lower limit of |V{sub tb}| > 0.77.
Uncovering the single top: Observation of electroweak top quark production
NASA Astrophysics Data System (ADS)
Benitez, Jorge Armando
The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as "Single Top." Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element Vtb, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb-1 of Data collected with the DO detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: spp→tb+X,tqb+X =3.74+0.95-0.74pb, 1 where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10-6. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting cross section measurement is: spp→tb+X,tqb+X =3.94+/-0.88pb, 2 and the corresponding measurement significance is 5.0 standard deviations.
Quark matter symmetry energy and quark stars
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.
Meson properties in a nonlocal SU(3) chiral quark model at finite temperature
Contrera, G. A.; Gomez Dumm, D.; Scoccola, N. N.
2010-11-12
Finite temperature meson properties are studied in the context of a nonlocal SU(3) quark model which includes flavor mixing and the coupling of quarks to the Polyakov loop (PL). We analyze the behavior of scalar and pseudoscalar meson masses and mixing angles, as well as quark-meson couplings and pseudoscalar meson decay constants.
Quark matter and meson properties in a Nonlocal SU(3) chiral quark model at finite temperature
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.
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.
Flavor Physics in the Quark Sector
Antonelli, Mario; Asner, David Mark; Bauer, Daniel Adams; Becher, Thomas G.; Beneke, M.; Bevan, Adrian John; Blanke, Monika; Bloise, C.; Bona, Marcella; Bondar, Alexander E.; Bozzi, Concezio; Brod, Joachim; Buras, Andrzej J.; Cabibbo, N.; Carbone, A.; Cavoto, Gianluca; Cirigliano, Vincenzo; Ciuchini, Marco; Coleman, Jonathon P.; Cronin-Hennessy, Daniel P.; Dalseno, J.P.; /KEK, Tsukuba /Glasgow U. /Queen Mary, U. of London /Freiburg U. /Charles U. /Pisa U. /Vienna, OAW /Imperial Coll., London /Bergen U. /INFN, Rome /Rome U. /Munich, Tech. U. /INFN, Rome /Rome U. /Southampton U. /INFN, Rome /Nara Women's U. /Florida U. /INFN, Turin /Turin U. /Edinburgh U. /Warwick U. /INFN, Rome /Rome U. /Massachusetts U., Amherst /KEK, Tsukuba /Bern U. /CERN /Munich, Tech. U. /Mainz U., Inst. Phys. /Wayne State U. /Munich, Max Planck Inst. /CERN /Frascati /Brookhaven /Mainz U., Inst. Kernphys. /Munich, Tech. U. /Siegen U. /Imperial Coll., London /Victoria U. /KEK, Tsukuba /Fermilab /Washington U., St. Louis /Frascati /Warwick U. /Indian Inst. Tech., Madras /Melbourne U. /Princeton U. /Beijing, Inst. High Energy Phys. /INFN, Rome /INFN, Rome3 /Fermilab /SLAC /York U., Canada /Brookhaven /UC, Irvine /INFN, Rome /Rome U. /Valencia U., IFIC /INFN, Padua /Padua U. /Munich, Max Planck Inst. /Barcelona U. /Warwick U. /Tata Inst. /Frascati /Mainz U., Inst. Phys. /Vienna U. /KEK, Tsukuba /Orsay, LPT /Frascati /Munich, Tech. U. /Brookhaven /Bern U. /CERN /Mainz U., Inst. Phys. /Wayne State U. /Valencia U., IFIC /CERN /Kentucky U. /Oxford U. /Iowa State U. /Bristol U. /INFN, Rome /Rutherford /CERN /Orsay, LAL /Glasgow U. /INFN, Padua /Queen Mary, U. of London /Texas U. /LPHE, Lausanne /Fermilab /UC, Santa Cruz /Vienna, OAW /Cincinnati U. /Frascati /Orsay, LAL /Ohio State U. /Purdue U. /Novosibirsk, IYF /Frascati /INFN, Rome /Padua U. /INFN, Rome /Bern U. /Karlsruhe U. /Brookhaven /CERN /Paris U., VI-VII /Zurich, ETH /Pisa U. /Frascati /Oxford U. /Orsay, LAL /INFN, Rome2 /INFN, Rome /INFN, Rome3 /Princeton U. /Fermilab /Queen's U., Kingston /KEK, Tsukuba /Melbourne U. /Brookhaven /Indiana U. /INFN, Rome /Rome U. /Pisa U. /Mainz U., Inst. Phys. /Karlsruhe U. /Oxford U. /Cambridge U., DAMTP /Edinburgh U. /CERN
2010-08-26
In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor. In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and quantum numbers, there now exist detailed measurements of the characteristics of their interactions allowing stringent tests of Standard Model predictions. Among the most interesting phenomena of flavor physics is the violation of the CP symmetry that has been subtle and difficult to explore. In the past, observations of CP violation were confined to neutral K mesons, but since the early 1990s, a large number of CP-violating processes have been studied in detail in neutral B mesons. In parallel, measurements of the couplings of the heavy quarks and the dynamics for their decays in large samples of K,D, and B mesons have been greatly improved in accuracy and the results are being used as probes in the search for deviations from the Standard Model. In the near future, there will be a transition from the current to a new generation of experiments, thus a review of the status of quark flavor physics is timely. This report is the result of the work of the physicists attending the 5th CKM workshop, hosted by the University of Rome 'La Sapienza', September 9-13, 2008. It summarizes the results of the current generation of experiments that is about to be completed and it confronts these results with the theoretical understanding of the field which has greatly improved in the past decade.
Adler, S.L.
1999-01-01
We construct extensions of the standard model based on the hypothesis that Higgs bosons also exhibit a family structure and that the flavor weak eigenstates in the three families are distinguished by a discrete Z{sub 6} chiral symmetry that is spontaneously broken by the Higgs sector. We study in detail at the tree level models with three Higgs doublets and with six Higgs doublets comprising two weakly coupled sets of three. In a leading approximation of S{sub 3} cyclic permutation symmetry the three-Higgs-doublet model gives a {open_quotes}democratic{close_quotes} mass matrix of rank 1, while the six-Higgs-doublet model gives either a rank-1 mass matrix or, in the case when it spontaneously violates {ital CP}, a rank-2 mass matrix corresponding to nonzero second family masses. In both models, the CKM matrix is exactly unity in the leading approximation. Allowing small explicit violations of cyclic permutation symmetry generates small first family masses in the six-Higgs-doublet model, and first and second family masses in the three-Higgs-doublet model, and gives a nontrivial CKM matrix in which the mixings of the first and second family quarks are naturally larger than mixings involving the third family. Complete numerical fits are given for both models, flavor-changing neutral current constraints are discussed in detail, and the issues of unification of couplings and neutrino masses are addressed. On a technical level, our analysis uses the theory of circulant and retrocirculant matrices, the relevant parts of which are reviewed. {copyright} {ital 1998} {ital The American Physical Society}
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.
Quark confinement in a constituent quark model
Langfeld, K.; Rho, M.
1995-07-01
On the level of an effective quark theory, we define confinement by the absence of quark anti-quark thresholds in correlation function. We then propose a confining Nambu-Jona-Lasinio-type model. The confinement is implemented in analogy to Anderson localization in condensed matter systems. We study the model`s phase structure as well as its behavior under extreme conditions, i.e. high temperature and/or high density.
Heavy Baryons in a Quark Model
Winston Roberts; Muslema Pervin
2007-11-14
A quark model is applied to the spectrum of baryons containing heavy quarks. The model gives masses for the known heavy baryons that are in agreement with experiment, but for the doubly-charmed baryon $\\Xi_{cc}$, the model prediction is too heavy. Mixing between the $\\Xi_Q$ and $\\Xi_Q^\\prime$ states is examined and is found to be small for the lowest lying states. In contrast with this, mixing between the $\\Xi_{bc}$ and $\\Xi_{bc}^\\prime$ states is found to be large, and the implication of this mixing for properties of these states is briefly discussed. We also examine heavy-quark spin-symmetry multiplets, and find that many states in the model can be placed in such multiplets.
Observation of electroweak single top-quark production.
Aaltonen, T; Adelman, J; Akimoto, T; 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; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; 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; 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Garosi, P; 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; 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; 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2009-08-28
We report the observation of single top-quark production using 3.2 fb(-1) of pp[over ] collision data with sqrt[s]=1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity for standard model production and decay is in excess of 5.9 standard deviations. Assuming m(t) = 175 GeV/c(2), we measure a cross section of 2.3(-0.5);(+0.6)(stat + syst) pb, extract the CKM matrix-element value |V(tb)| = 0.91 + or - 0.11(stat + syst) + or - 0.07(theory), and set the limit |V(tb)| > 0.71 at the 95% C.L. PMID:19792788
First Observation of Electroweak Single Top Quark Production
Aaltonen, T.; Adelman, J.; Akimoto, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, Dante E.; Anastassov, A.; Annovi, Alberto; Antos, Jaroslav; Apollinari, G.; Apresyan, A.; /Purdue U. /Waseda U.
2009-03-01
We report the first observation of single top quark production using 3.2 fb{sup -1} of p{bar p} collision data with {radical}s = 1.96 TeV collected by the Collider Detector at Fermilab. The significance of the observed data is 5.0 standard deviations, and the expected sensitivity is in excess of 5.9 standard deviations. We measure a cross section of 2.3{sub -0.5}{sup +0.6}(stat + syst) pb, extract the CKM matrix element value |V{sub tb}| = 0.91{sub -0.11}{sup +0.11}(stat + syst) {+-} 0.07(theory), and set the limit |V{sub tb}| > 0.71 at the 95% C.L.
Correlating lepton mixing angles and mixing maxtrix with Wolfenstein parameters
NASA Astrophysics Data System (ADS)
Zhang, Xinyi; Ma, Bo-Qiang
2012-11-01
Inspired by a new relation θ13PMNS=θC/2 observed from the relatively large θ13PMNS, we find that the combination of this relation with the quark-lepton complementarity and the self-complementarity results in correlations of the lepton mixing angles with the quark mixing angles. We find that the three mixing angles in the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix are all related to the Wolfenstein parameter λ in the quark mixing, so they are also correlated. Consequently, the PMNS matrix can be parameterized by λ, A, and a Dirac CP-violating phase δ. Such parametrizations for the PMNS matrix have the same explicitly hierarchical structure as the Wolfenstein parametrization for the Cabibbo-Kobayashi-Maskawa matrix in the quark mixing, and the bimaximal mixing pattern is deduced at the leading order. We also discuss implications of these phenomenological relations in parametrizations.
Santopinto, E.; Bijker, R.
2008-10-13
We present a new generation of unquenched quark models for baryons in which the effects of quark-antiquark pairs are taken into account in an explicit form via a microscopic, QCD-inspired, pair creation mechanism. As an application, we study the effect of quark-antiquark pairs on the spin of the proton.
Status of CKM angle measurements, a report from BaBar and Belle
Long, Owen; /UC, Riverside
2010-08-26
I will review the latest developments in determining the CP-violating phases of the CKM matrix elements from measurements by the BaBar and BELLE experiments at the high-luminosity B factories (PEP-II and KEKB). The emphasis will be on the angle {gamma}/{phi}{sub 3} of the Unitarity Triangle, which is the relative phase arg(-V{sub ud}V*{sub ub}/V{sub cd}V*{sub cb}), or the CP-violating phase of the b {yields} u transition in the commonly used Wolfenstein convention.
Chiral perturbation theory for staggered sea quarks and Ginsparg-Wilson valence quarks
Baer, Oliver; Bernard, Claude; Rupak, Gautam; Shoresh, Noam
2005-09-01
We study lattice QCD with staggered sea and Ginsparg-Wilson valence quarks. The Symanzik effective action for this mixed lattice theory, including the lattice spacing contributions of O(a{sup 2}), is derived. Using this effective theory we construct the leading-order chiral Lagrangian. The masses and decay constants of pseudoscalars containing two Ginsparg-Wilson valence quarks are computed at one-loop order.
Uncovering the single top: observation of electroweak top quark production
Benitez, Jorge Armando
2009-01-01
The top quark is generally produced in quark and anti-quark pairs. However, the Standard Model also predicts the production of only one top quark which is mediated by the electroweak interaction, known as 'Single Top'. Single Top quark production is important because it provides a unique and direct way to measure the CKM matrix element V_{tb}, and can be used to explore physics possibilities beyond the Standard Model predictions. This dissertation presents the results of the observation of Single Top using 2.3 fb^{-1} of Data collected with the D0 detector at the Fermilab Tevatron collider. The analysis includes the Single Top muon+jets and electron+jets final states and employs Boosted Decision Tress as a method to separate the signal from the background. The resulting Single Top cross section measurement is: (1) σ(p$\\bar{p}$→ tb + X, tqb + X) = 3.74_{-0.74}^{+0.95} pb, where the errors include both statistical and systematic uncertainties. The probability to measure a cross section at this value or higher in the absence of signal is p = 1.9 x 10^{-6}. This corresponds to a standard deviation Gaussian equivalence of 4.6. When combining this result with two other analysis methods, the resulting cross section measurement is: (2) σ(p$\\bar{p}$ → tb + X, tqb + X) = 3.94 ± 0.88 pb, and the corresponding measurement significance is 5.0 standard deviations.
Study of rare decays of the b quark with the DELPHI detector at LEP
NASA Astrophysics Data System (ADS)
Battaglia, Marco
The b quark is the heaviest fermion producing bound hadronic states. The study of their production and decays provides important data for the understanding of the processes responsible for the weak decays of fundamental fermions. In addition, due to the small value of the | Vcb| element, suppressed and rare b-->u and b-->s, d transitions are not completely obliterated by the CKM favoured b-->c decays. This makes B hadrons an ideal laboratory for the study of rare decay processes. The sensitivity of these decays to the Standard Model structure, through suppressions proportional to the square of the elements in the quark mixing matrix and through loops that may reveal contributions of new particles, opens a new window on precision tests of the Standard Model and also on possible new physics beyond it. The DELPHI detector, equipped with a precise silicon vertex tracker surrounding the beam interaction region and with Ping Imaging CHerenkov (RICH) detectors providing efficient hadron identification, at the LEP e +e- collider, is well suited for precise studies of B decays. This thesis presents the results of the analysis of the date, collected with DELPHI at centre-of-mass energies around the Z0 pole from 1990 to 1995 for the studies of rare decays of beauty hadrons. These studies have promoted the development of new techniques for the topological reconstruction of the B decay chain and for hadron identification based on the response of the RICH detectors. Rare decays of the b quarks have been studied in several decay processes. Tree level b-->u transitions have been studied mainly in the semileptonic b-->uln channel. A new technique that discriminate them from the favoured b-->c transitions based on the reconstructed mass of the hadronic system recoiling against the lepton has been developed and applied. Evidence for the decay has been obtained and its rate has been used to extract an accurate determination of the |Vub| element in the quark mixing matrix. Hadronic
Measurement of the CKM Angle Alpha at the BABAR Detector Using B Meson Decays to Rho Final States
Mihalyi, Attila; /Wisconsin U., Madison
2006-10-16
This thesis contains the results of an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} using 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a fitted signal yield of 617 {+-} 52 events, the longitudinal polarizations fraction, f{sub L}, of the decay is measured to be 0.978 {+-} 0.014(stat){sub -0.029}{sup +0.021}(syst). The nearly fully longitudinal dominance of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay allows for a measurement of the time dependent CP parameters S{sub L} and C{sub L}, where the first parameter is sensitive to mixing induced CP violation and the second one to direct CP violation. From the same signal yield, these values are found to be S{sub L} = -0.33 {+-} 0.24(stat){sub -0.14}{sup +0.08}(syst) and C{sub L} = - 0.03 {+-} 0.18(stat) {+-} 0.09(syst). The CKM angle {alpha} is then determined, using these results and the branching fractions and polarizations of the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} and B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. This measurement is done with an isospin analysis, in which a triangle is constructed from the isospin amplitudes of these three decay modes. A {chi}{sup 2} expression that includes the measured quantities expressed as the lengths of the sides of the isospin triangles is constructed and minimized to determine a confidence level on {alpha}. Selecting the solution compatible with the Standard Model, one obtains {alpha} = 100{sup o} {+-} 13{sup o}.
Quark Orbital Angular Momentum
NASA Astrophysics Data System (ADS)
Burkardt, Matthias
2016-06-01
Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.
Measurement of the Single Top Quark Production Cross Section at $\\sqrt {s} = 1.96$ TeV
Padilla, Mark Anthony
2011-01-01
Within the standard model top quarks are predicted to be most often produced in pairs via the strong interaction. However they can also be produced singly through the weak interation. This is a rarer process with many experimental challenges. It is interesting because it provides a new window to search for evidence of physics beyond the standard model picture, such as a fourth generation of quarks or to search for insight into the Higgs Mechanism. Single top production also provides a direct way to calculate the CKM matrix element V_{tb}. This thesis presents new measurements for single top quark production in the s+t, s and t channels using 5.4 fb^{-1} of data collected at the DØ detector at Fermilab in Batavia, IL. The analysis was performed using Boosted decision trees to separate signal from background and Bayesian statistcs to calculate all the cross sections.
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.
Precision QEC-value measurement of 23Mg for testing the CKM matrix unitarity
NASA Astrophysics Data System (ADS)
Brodeur, Maxime; Schultz, Brad; Dilling, Jens; Titan Collaboration
2014-09-01
We report a new direct measurement of the 23Mg β+-decay transition energy QEC using the TITAN Penning trap mass spectrometer. This value agrees with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC-value on the statistical rate function fv from 11 % to 0.6 %, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft -value of this mirror transition to the required precision, making possible further test of the CKM matrix unitarity. We report a new direct measurement of the 23Mg β+-decay transition energy QEC using the TITAN Penning trap mass spectrometer. This value agrees with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC-value on the statistical rate function fv from 11 % to 0.6 %, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft -value of this mirror transition to the required precision, making possible further test of the CKM matrix unitarity. Natural Sciences and Engineering Research Council of Canada.
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.
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.
Catara, F.; Sambataro, M. Italy Dipartimento di Fisica dell'Universita, 95129 Catania )
1992-08-01
By making use of a mapping procedure recently proposed, we construct the nucleon image of the one-body quark density operator in the framework of the nonrelativistic quark model of the nucleons. We evaluate the expectation value of this operator in the ground state of the doubly magic nuclei {sup 4}He, {sup 16}O, and {sup 40}Ca described within the nuclear shell model. We analyze the role of quark exchanges between nucleons. We also investigate the effect on the quark density of short-range correlations in the nuclear wave functions as well as of variations in the nucleon size.
ERIC Educational Resources Information Center
Dakin, James T.
1974-01-01
Reviews theoretical principles underlying the quark model. Indicates that the agreement with experimental results and the understanding of the quark-quark force are two hurdles for the model to survive in the future. (CC)
Evidence for production of single top quarks
Abazov, V. M.; Alexeev, G. D.; Kalinin, A. M.; Kharzheev, Y. M.; Malyshev, V. L.; Tokmenin, V. V.; Vertogradov, L. S.; Yatsunenko, Y. A.; Abbott, B.; Gutierrez, P.; Hossain, S.; Jain, S.; Rominsky, M.; Severini, H.; Skubic, P.; Strauss, M.; Abolins, M.; Benitez, J. A.; Brock, R.; Dyer, J.
2008-07-01
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron pp collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9 fb{sup -1} data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and tt events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of {sigma}(pp{yields}tb+X,tqb+X)=4.7{+-}1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |V{sub tb}f{sub 1}{sup L}|=1.31{sub -0.21}{sup +0.25}, where f{sub 1}{sup L} is a generic vector coupling. This model-independent measurement translates into 0.68<|V{sub tb}|{<=}1 at the 95% C.L. in the standard model.
Evidence for production of single top quarks
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /St. Petersburg, INP /Michigan U.
2008-03-01
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron p{bar p} collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top quark partner that is always produced from strong coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top quark production has been searched for in ever larger datasets. In this analysis, we select events from a 0.9 fb{sup -1} dataset that have an electron or muon and missing transverse energy from the decay of a W boson from the top quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and t{bar t} events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top quark production of {sigma}(p{bar p} {yields} tb + X, tqb + X) = 4.7 {+-} 1.3 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |V{sub tb}f{sub 1}{sup L}| = 1.31{sub -0.21}{sup +0.25}, where f{sub 1}{sup L} is a generic vector coupling. This model-independent measurement translates into 0.68 < |V{sub tb}| {le} 1 at the 95% C.L. in the standard model.
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.
Blankenbecler, R.
1981-01-01
A brief review is given of selected topics involved in the relativistic quark structure of nuclei such as the infinite momentum variables, scaling variables, counting rules, forward-backward variables, thermodynamic-like limit, QCD effects, higher quark bags, confinement, and many unanswered questions.
NASA Astrophysics Data System (ADS)
Watson, Andrew
2008-11-01
Preface; Acknowledgments; 1. Introduction; 2. Symmetry; 3. The quantum world; 4. Towards QCD; 5. The one number of QCD; 6. The gregarious gluon; 7. Quarks and hadrons; 8. Quarks under the microscope; 9. Much ado about nothing; 10. Checkerboard QCD; Appendix 1. A QCD chronology; Appendix 2. Greek alphabet and SI prefixes; Appendix 3. Glossary; Appendix 4. Further reading; Index.
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.
Erbacher, Robin D.; /UC, Davis
2005-10-01
While the top quark was discovered in 1995 at the Fermilab Tevatron, a decade later they still have very little information about the top. As the heaviest particle yet discovered, the top quark is interesting in and of itself, but some speculate that it may play a special role in physics beyond the Standard Model. With Run 2 of the Tevatron well underway, they have the opportunity to study top quark properties with much better sensitivity, and to test whether top quarks behave as predicted by current theories. This article focuses on the basics of top quark physics at the Tevatron, highlighting only a sample of the many recent measurements, as new results are being released monthly, and constantly changing the landscape of our knowledge of top.
NASA Astrophysics Data System (ADS)
Ma, Ernest; Melić, Blaženka
2013-10-01
A model proposed in 2004 using the non-Abelian discrete symmetry S3 for understanding the flavor structure of quarks and leptons is updated, with special focus on the quark and scalar sectors. We show how the approximate residual symmetries of this model explain both the pattern of the quark mixing matrix and why the recently observed particle of 126 GeV at the Large Hadron Collider is so much like the one Higgs boson of the Standard Model. We identify the strongest phenomenological bounds on the scalar masses of this model, and predict a possibly observable decay b → sτ-μ+ (Bs →τ+μ-), but not b → sτ+μ- (Bs →τ-μ+).
Determination of the width of the top quark.
Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; 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; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; 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; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Ćwiok, M; 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; 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; Eno, S; 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; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; 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; Guo, F; Guo, J; 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; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; 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; 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; Love, P; 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; 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; Owen, M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; 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; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; 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; Vint, P; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; 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; Yoo, H D; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L
2011-01-14
We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3 fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69) GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25) s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L. PMID:21405220
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.
Phase diagram of neutral quark matter in nonlocal chiral quark models
NASA Astrophysics Data System (ADS)
Gómez Dumm, D.; Blaschke, D. B.; Grunfeld, A. G.; Scoccola, N. N.
2006-06-01
We consider the phase diagram of two-flavor quark matter under neutron star constraints for two nonlocal, covariant quark models within the mean-field approximation. In the first case (Model I) the nonlocality arises from the regularization procedure, motivated by the instanton liquid model, whereas in the second one (Model II) a separable approximation of the one-gluon exchange interaction is applied. We find that Model II predicts a larger quark mass gap and a chiral symmetry breaking (CSB) phase transition line which extends 15 20% further into the phase diagram spanned by temperature (T) and chemical potential (μ). The corresponding critical temperature at μ=0, Tc(0)≃140MeV, is in better accordance to recent lattice QCD results than the prediction of the standard local NJL model, which exceeds 200 MeV. For both Model I and Model II we have considered various coupling strengths in the scalar diquark channel, showing that different low-temperature quark matter phases can occur at intermediate densities: a normal quark matter (NQM) phase, a two-flavor superconducting (2SC) quark matter phase and a mixed 2SC-NQM phase. Although in most cases there is also a gapless 2SC phase, this occurs in general in a small region at nonzero temperatures, thus its effect should be negligible for compact star applications.
Measurement of CP violation and constraints on the CKM angle γ in B±→DK± with D→KS0π+π- decays
NASA Astrophysics Data System (ADS)
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Balagura, V.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjørnstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; van den Brand, J.; Bressieux, J.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Busetto, G.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Camboni, A.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carranza-Mejia, H.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Ciba, K.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R. F.; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gaspar, C.; Gauld, R.; Gavardi, L.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani', S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gordon, H.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; Hartmann, T.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kaballo, M.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanciotti, E.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, G.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lu, H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martens, A.; Martín Sánchez, A.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Moggi, N.; Molina Rodriguez, J.; Monteil, S.; Moran, D.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A.-B.; Mountain, R.; Muheim, F.; Müller, K.; Muresan, R.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, G.; Orlandea, M.; Otalora Goicochea, J. M.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pazos Alvarez, A.; Pearce, A.; Pellegrino, A.; Pepe Altarelli, M.; Perazzini, S.; Perez Trigo, E.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Powell, A.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, A.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Roa Romero, D. A.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruffini, F.; Ruiz, H.; Ruiz Valls, P.; Sabatino, G.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sapunov, M.; Sarti, A.; Satriano, C.; Satta, A.; Savrie, M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Seco, M.; Semennikov, A.; Senderowska, K.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Sparkes, A.; Spradlin, P.; Stagni, F.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szilard, D.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ubeda Garcia, M.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; Voss, H.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wu, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, F.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zvyagin, A.
2014-11-01
A model-dependent amplitude analysis of B±→DK± with D→KS0π+π- decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 1 fb, recorded by LHCb at a centre-of-mass energy of 7 TeV in 2011. Values of the CP violation observables x± and y±, which are sensitive to the CKM angle γ, are measured to be x-=+0.027±0.044-0.008+0.010±0.001, y-=+0.013±0.048-0.007+0.009±0.003, x+=-0.084±0.045±0.009±0.005, y+=-0.032±0.048-0.009+0.010±0.008, where the first uncertainty is statistical, the second systematic and the third arises from the uncertainty of the D→KS0π+π- amplitude model. The value of γ is determined to be (84-42+49)°, including all sources of uncertainty. Neutral D meson mixing is found to have negligible effect.
Flavor signatures of isosinglet vector-like down quark model
NASA Astrophysics Data System (ADS)
Alok, Ashutosh Kumar; Banerjee, Subhashish; Kumar, Dinesh; Uma Sankar, S.
2016-05-01
We consider a model where the standard model is extended by the addition of a vector-like isosinglet down-type quark b‧. We perform a χ2 fit to the flavor physics data and obtain the preferred central values along with errors of all the elements of the measurable 3 × 4 quark mixing matrix. The fit indicates that all the new-physics parameters are consistent with zero and the mixing of the b‧ quark with the other three is constrained to be small. The current flavor physics data rules out possibility of detectable new physics signals in most of the flavor physics observables. We also investigate possible deviations in the standard model Wtb couplings and bottom quark coupling to Higgs boson. We find that these deviations are less than a percent level which is too small to be observed at the LHC with current precision.
B Decay and CP Violation: CKM Angles and Sides at the BABAR and BELLE B-Factories
Verderi, Marc; /Ecole Polytechnique
2011-11-28
A remarkable success has been achieved by the B-Factories, going beyond expectation in some field, like the measurement of {gamma}. BABAR has now finished its data taking, leaving BELLE alone in the 'race', but still many analyses are going on. The CKM UT is constrained by both measurements of CP-conserving and CP-violating quantities, leading to a picture of the CKM sector consistent with the SM. Measurements of semi-leptonic decays benefit from improving experimental techniques and more precise theoretical computations. The angle {beta} is a precision measurement, reaching accuracy of SM calculation. The angle {alpha} will ultimatly be limited by penguin pollution. The measurement of {gamma} is reaching the 13{sup o} precision.
Testing for three-body quark forces in L = 1 excited baryons
Pirjol, Dan; Schat, Carlos
2010-11-12
We discuss the matching of the quark model to the effective mass operator of the 1/N{sub c} expansion using the permutation group S{sub N}. As an illustration of the general procedure we perform the matching of the Isgur-Karl model for the spectrum of the negative parity L = 1 excited baryons. Assuming the most general two-body quark Hamiltonian, we derive two correlations among the masses and mixing angles of these states which should hold in any quark model. These correlations constrain the mixing angles and can be used to test for the presence of three-body quark forces.
CP violation in a two-Higgs doublet model for the top quark: B-->ψKS
NASA Astrophysics Data System (ADS)
Kiers, Ken; Soni, Amarjit; Wu, Guo-Hong
1999-05-01
We explore charged-Higgs CP-violating effects in an intriguing two-Higgs doublet model which accords special status to the top quark. In this model the heaviness of the top quark originates naturally from the much larger VEV of the second Higgs doublet compared to that of the first. The phenomenology of this model is quite distinct from that of the usual formulations of the two-Higgs doublet model. In particular, the model can easily account for the observed CP violation in the kaon sector even if the CKM matrix is real. The associated non-standard CP phase can be monitored through measurements of the time-dependent CP asymmetry in B-->ψKS in experiments at the upcoming B factories.
(Beta)-decay experiments and the unitarity of the CKM matrix
Garrett, P E
2005-12-01
The goal of this project was to perform very precise measurements of super-allowed Fermi {beta} decay in order to investigate a possible non-unitarity in the CKM matrix of the Standard Model of particle physics. Current data from 9 precisely measured {beta} decays indicated that the sum-of-squares of the first row of the CKM matrix differs from 1.0 at the 2.2{sigma} (or 98% confidence) level. If true, it would be the first firm indication of physics beyond the Standard Model--the model that has been the backbone of the worldwide physics community for more than 30 years. The physics goal of the project was to test and constrain the calculated correction factors that must be applied to the experimental data by performing measurements at the TRIUMF radioactive ion beam facility ISAC. Accurate and precise (precision goal >99.9%) half lives and decay branching ratios were measured for nuclei where different sets of calculated corrections give divergent results thereby allowing us to determine which theory, if any, gives the correct result. The LLNL contribution was to design and build the data acquisition system that will enable the experiments, and to provide theoretical calculations necessary for the interpretation of the results. The first planned measurement was {sup 34}Ar, to be followed by {sup 62}Ga and {sup 74}Rb. However, there were major problems in creating a suitable, intense beam of radioactive {sup 34}Ar. The collaboration decided to proceed with measurements on {sup 62}Ga and {sup 18}Ne. These experiments were performed in a series of measurements in the summer and fall of 2004. The LLNL team also is leading the effort to perform measurements on {sup 66}As and {sup 70}Br that are expected during 2006-2008. While the definitive experiments to meet the goals of the LDRD were not conducted during the funding period, the involvement in the radioactive program at TRIUMF has lead to a number of new initiatives, and has attracted new staff to LLNL. This LDRD has
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.
Generation mixing and CP-violation, standard and beyond
Harari, H.
1987-05-01
We discuss several issues related to the observed generation pattern of quarks and leptons. Among the main topics: Masses, angles and phases and possible relations among them, a possible fourth generation of quarks and leptons, new bounds on neutrino masses, comments on the recently observed mixing in the B - anti B system, CP-violation, and recent proposals for a b-quark ''factory''.
Generalized parton distributions from domain wall valence quarks and staggered sea quarks
Renner, Dru; Bratt, Jonathan; Edwards, Robert; Engelhardt, Michael; Fleming, George; Haegler, Philipp; Musch, Bernhard; Negele, John; Orginos, Konstantinos; Pochinsky, Andrew; Richards, David; Schroers, Wolfram
2007-11-01
Moments of the generalized parton distributions of the nucleon, calculated with a mixed action of domain wall valence quarks and asqtad staggered sea quarks, are presented for pion masses extending down to 359 MeV. Results for the moments of the unpolarized, helicity, and transversity distributions are given and compared to the available experimental measurements. Additionally, a selection of the generalized form factors are shown and the implications for the spin decomposition and transverse structure of the nucleon are discussed. Particular emphasis is placed on understanding systematic errors in the lattice calculation and exploring a variety of chiral extrapolations.
Rare top quark decays in extended models
Gaitan, R.; Miranda, O. G.; Cabral-Rosetti, L. G.
2006-09-25
Flavor changing neutral currents (FCNC) decays t {yields} H0 + c, t {yields} Z + c, and H0 {yields} t + c-bar are discussed in the context of Alternative Left-Right symmetric Models (ALRM) with extra isosinglet heavy fermions where FCNC decays may take place at tree-level and are only suppressed by the mixing between ordinary top and charm quarks, which is poorly constraint by current experimental values. The non-manifest case is also briefly discussed.
Evidence for B- to rho0rho0 Decay and Implications for the CKM Angle alpha
Aubert, B.
2007-01-03
The authors search for the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0}, B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980), and B{sup 0} {yields} f{sub 0}(980) f{sub 0}(980) in a sample of about 384 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find evidence for B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} with 3.5{sigma} significance and measure the branching fraction {Beta} = (1.07 {+-} 0.33 {+-} 0.19) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.87 {+-} 0.13 {+-} 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the CKM unitarity angle {alpha} due to penguin contributions in B {yields} {rho}{rho} decays is 18{sup o} at the 1{sigma} level. They also set upper limits on the B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980) and B{sup 0} {yields} f{sub 0}(980)f{sub 0}(980) decay rates.
Constraints on the CKM Angle alpha in the B to rho rho Decays
Li, H.
2004-11-03
Using a data sample of 122 million {Upsilon}(4S) {yields} B{bar B} decays collected with BABAR detector at the PEP-II asymmetric B factory at SLAC, we measure the time-dependent-asymmetry parameters of the longitudinally polarized component in the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay as C{sub L} = -0.23 {+-} 0.24(stat) {+-} 0.14(syst) and S{sub L} = -0.19 {+-} 0.33(stat) {+-} 0.11(syst). The B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decay mode is also searched for in a data sample of about 227 million B{bar B} pairs. No significant signal is observed, and an upper limit of 1.1 x 10{sup -6} (90% C.L.) on the branching fraction is set. The penguin contribution to the CKM angle {alpha} uncertainty is measured to be 11{sup o}. All results are preliminary.
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.
B0(s) mixing studies at the Tevatron
Naimuddin, M.D.; /Delhi U.
2006-05-01
Measurement of the B{sub s}{sup 0} oscillation frequency via B{sub s}{sup 0} mixing analysis provides a powerful constraint on CKM matrix elements. This note briefly reviews the motivation behind these analyses and describes the various steps that go into a mixing measurement. Recent results on B{sub s}{sup 0} mixing obtained by the CDF and D0 collaborations using the data samples collected at Tevatron Collider in the period 2002-2005 are presented.
Quark and lepton flavor triality
Ma, Ernest
2010-08-01
Motivated by the success of A{sub 4} in explaining neutrino tribimaximal mixing, and its approximate residual Z{sub 3} symmetry in the quark and charged-lepton sectors, the notion of flavor triality is proposed. Under this hypothesis, certain processes such as {tau}{sup +}{yields}{mu}{sup +}{mu}{sup +}e{sup -} and {tau}{sup +}{yields}e{sup +}e{sup +}{mu}{sup -} are favored, but {tau}{sup +}{yields}{mu}{sup +}e{sup +}e{sup -} and {mu}{sup +}{yields}e{sup +}e{sup +}e{sup -} are disfavored. Similarly, B{sup 0}{yields}{tau}{sup +}e{sup -} is favored, but B{sup 0}{yields}{tau}{sup -}e{sup +} is disfavored.
NASA Astrophysics Data System (ADS)
Friedman, J. I.
2001-01-01
In the period following World War II, there was a rapid development of particle physics. With the construction of synchrotrons and the development of detector technology, many new particles were discovered and the systematics of their interactions investigated. The invention of the bubble chamber played an especially important role in uncovering the rich array of hadrons that were discovered in this period.In 1961 Murray Gell-Mann [1] and Yuval Ne'eman [2] independently introduced a classification scheme, based on SU(3) symmetry, which placed hadrons into families on the basis of spin and parity. Like the periodic table for the elements, this scheme was predictive as well as descriptive, and various hadrons, such as the - , were predicted within this framework and were later discovered.In 1964 Gell-Mann [3] and George Zweig [4] independently proposed quarks as the building blocks of hadrons as a way of generating the SU(3) classification scheme. When the quark model was first proposed, it postulated three types of quarks: up (u), down (d), and strange (s), with charges 2/3, - 1/3, and - 1/3 respectively. Each of these was hypothesized to be a spin1/2 particle. In this model the nucleon (and all other baryons) is made up of three quarks, and each meson consists of a quark and an antiquark. For example, as the proton and neutron both have ero strangeness, they are (u,u,d) and (d,d,u) systems respectively.
Evidence for production of single top quarks and first direct measurement of |Vtb|
Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahn, S.H.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; /Buenos Aires U. /Rio de Janeiro, CBPF /Rio de Janeiro State U. /Sao Paulo, IFT /Alberta U. /Simon Fraser U. /York U., Canada /McGill U. /Hefei, CUST /Andes U., Bogota /Charles U.
2006-12-01
The D0 Collaboration presents first evidence for the production of single top quarks at the Fermilab Tevatron p{bar p} collider. Using a 0.9 fb{sup -1} dataset, we apply a multivariate analysis to separate signal from background and measure {sigma}(p{bar p} {yields} tb + X, tqb + X) = 4.9 {+-} 1.4 pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.035%, corresponding to a 3.4 standard deviation significance. We use the cross section measurement to directly determine the CKM matrix element that describes the W tb coupling and find 0.68 < |V{sub tb}| {le} 1 at 95% C.L.
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)
Larsen, R.C.; Leipuner, L.B.; Morse, W.M.; Adair, R.K.; Kasha, H.; Schmidt, M.P.
1983-03-13
An experiment to search for quarks at the CBA is described. The cross sections for the production of massive quark-antiquark pairs in nucleon-nucleon interactions is estimated, and the experimental design and procedures are described. (WHK)
The Quark's Model and Confinement
ERIC Educational Resources Information Center
Novozhilov, Yuri V.
1977-01-01
Quarks are elementary particles considered to be components of the proton, the neutron, and others. This article presents the quark model as a mathematical concept. Also discussed are gluons and bag models. A bibliography is included. (MA)
Andreas S. Kronfeld
2003-11-05
This paper is a review of heavy quarks in lattice gauge theory, focusing on methodology. It includes a status report on some of the calculations that are relevant to heavy-quark spectroscopy and to flavor physics.
NASA Astrophysics Data System (ADS)
Fedi, G.; CMS Collaboration
2016-07-01
The most recent results which concern the heavy quark hadrons done in the CMS experiment are reported. The searching area spans over the heavy quark spectroscopy, production cross sections, beauty meson decay properties, rare decays, and CP violation.
Improved determination of the width of the top quark
Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; 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.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; 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-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery 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 Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; 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.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; 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.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; 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.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.
2012-05-04
We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.
Combined search for the quarks of a sequential fourth generation
NASA Astrophysics Data System (ADS)
Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Erö, J.; Fabjan, C.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hammer, J.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Pernicka, M.; Rahbaran, B.; Rohringer, C.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Taurok, A.; Waltenberger, W.; Walzel, G.; Widl, E.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Luyckx, S.; Mucibello, L.; Ochesanu, S.; Roland, B.; Rougny, R.; Selvaggi, M.; Staykova, Z.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Gonzalez Suarez, R.; Kalogeropoulos, A.; Maes, M.; Olbrechts, A.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Clerbaux, B.; De Lentdecker, G.; Dero, V.; Gay, A. P. R.; Hreus, T.; Léonard, A.; Marage, P. E.; Mohammadi, A.; Reis, T.; Thomas, L.; Vander Marcken, G.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Adler, V.; Beernaert, K.; Cimmino, A.; Costantini, S.; Garcia, G.; Grunewald, M.; Klein, B.; Lellouch, J.; Marinov, A.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Verwilligen, P.; Walsh, S.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Bruno, G.; Castello, R.; Ceard, L.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Lemaitre, V.; Liao, J.; Militaru, O.; Nuttens, C.; Pagano, D.; Pin, A.; Piotrzkowski, K.; Schul, N.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Alves, G. A.; Correa Martins Junior, M.; De Jesus Damiao, D.; Martins, T.; Pol, M. E.; Souza, M. H. G.; Aldá Júnior, W. L.; Carvalho, W.; Custódio, A.; Da Costa, E. M.; De Oliveira Martins, C.; Fonseca De Souza, S.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Oguri, V.; Prado Da Silva, W. L.; Santoro, A.; Soares Jorge, L.; Sznajder, A.; Anjos, T. S.; Bernardes, C. A.; Dias, F. A.; Tomei, T. R. Fernandez Perez; Gregores, E. M.; Lagana, C.; Marinho, F.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Genchev, V.; Iaydjiev, P.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Tcholakov, V.; Trayanov, R.; Vutova, M.; Dimitrov, A.; Hadjiiska, R.; Kozhuharov, V.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Jiang, C. H.; Liang, D.; Liang, S.; Meng, X.; Tao, J.; Wang, J.; Wang, X.; Wang, Z.; Xiao, H.; Xu, M.; Zang, J.; Zhang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Guo, S.; Guo, Y.; Li, W.; Liu, S.; Mao, Y.; Qian, S. J.; Teng, H.; Wang, D.; Zhang, L.; Zhu, B.; Zou, W.; Avila, C.; Gomez, J. P.; Gomez Moreno, B.; Osorio Oliveros, A. F.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Plestina, R.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Duric, S.; Kadija, K.; Luetic, J.; Morovic, S.; Attikis, A.; Galanti, M.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Finger, M.; Finger, M., Jr.; Assran, Y.; Elgammal, S.; Ellithi Kamel, A.; Khalil, S.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Müntel, M.; Raidal, M.; Rebane, L.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Heikkinen, A.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Ungaro, D.; Wendland, L.; Banzuzi, K.; Karjalainen, A.; Korpela, A.; Tuuva, T.; Besancon, M.; Choudhury, S.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Millischer, L.; Nayak, A.; Rander, J.; Rosowsky, A.; Shreyber, I.; Titov, M.; Baffioni, S.; Beaudette, F.; Benhabib, L.; Bianchini, L.; Bluj, M.; Broutin, C.; Busson, P.; Charlot, C.; Daci, N.; Dahms, T.; Dobrzynski, L.; Granier de Cassagnac, R.; Haguenauer, M.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Sabes, D.; Salerno, R.; Sirois, Y.; Veelken, C.; Zabi, A.; Agram, J.-L.; Andrea, J.; Bloch, D.; Bodin, D.; Brom, J.-M.; Cardaci, M.; Chabert, E. C.; Collard, C.; Conte, E.; Drouhin, F.; Ferro, C.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Juillot, P.; Le Bihan, A.-C.; Van Hove, P.; Fassi, F.; Mercier, D.; Beauceron, S.; Beaupere, N.; Bondu, O.; Boudoul, G.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Sordini, V.; Tschudi, Y.; Verdier, P.; Viret, S.; Tsamalaidze, Z.; Anagnostou, G.; Beranek, S.; Edelhoff, M.; Feld, L.; Heracleous, N.; Hindrichs, O.; Jussen, R.; Klein, K.; Merz, J.; Ostapchuk, A.; Perieanu, A.; Raupach, F.; Sammet, J.; Schael, S.; Sprenger, D.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Caudron, J.; Dietz-Laursonn, E.; Duchardt, D.; Erdmann, M.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Kreuzer, P.; Magass, C.; Merschmeyer, M.; Meyer, A.; Olschewski, M.; Papacz, P.; Pieta, H.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Steggemann, J.; Teyssier, D.; Weber, M.; Bontenackels, M.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Haj Ahmad, W.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Nowack, A.; Perchalla, L.; Pooth, O.; Sauerland, P.; Stahl, A.; Aldaya Martin, M.; Behr, J.; Behrenhoff, W.; Behrens, U.; Bergholz, M.; Bethani, A.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Castro, E.; Costanza, F.; Dammann, D.; Diez Pardos, C.; Eckerlin, G.; Eckstein, D.; Flucke, G.; Geiser, A.; Glushkov, I.; Gunnellini, P.; Habib, S.; Hauk, J.; Hellwig, G.; Jung, H.; Kasemann, M.; Katsas, P.; Kleinwort, C.; Kluge, H.; Knutsson, A.; Krämer, M.; Krücker, D.; Kuznetsova, E.; Lange, W.; Lohmann, W.; Lutz, B.; Mankel, R.; Marfin, I.; Marienfeld, M.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Olzem, J.; Perrey, H.; Petrukhin, A.; Pitzl, D.; Raspereza, A.; Ribeiro Cipriano, P. M.; Riedl, C.; Ron, E.; Rosin, M.; Salfeld-Nebgen, J.; Schmidt, R.; Schoerner-Sadenius, T.; Sen, N.; Spiridonov, A.; Stein, M.; Walsh, R.; Wissing, C.; Autermann, C.; Blobel, V.; Draeger, J.; Enderle, H.; Erfle, J.; Gebbert, U.; Görner, M.; Hermanns, T.; Höing, R. S.; Kaschube, K.; Kaussen, G.; Kirschenmann, H.; Klanner, R.; Lange, J.; Mura, B.; Nowak, F.; Peiffer, T.; Pietsch, N.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Schröder, M.; Schum, T.; Seidel, M.; Sola, V.; Stadie, H.; Steinbrück, G.; Thomsen, J.; Vanelderen, L.; Barth, C.; Berger, J.; Böser, C.; Chwalek, T.; De Boer, W.; Descroix, A.; Dierlamm, A.; Feindt, M.; Guthoff, M.; Hackstein, C.; Hartmann, F.; Hauth, T.; Heinrich, M.; Held, H.; Hoffmann, K. H.; Honc, S.; Katkov, I.; Komaragiri, J. R.; Lobelle Pardo, P.; Martschei, D.; Mueller, S.; Müller, Th.; Niegel, M.; Nürnberg, A.; Oberst, O.; Oehler, A.; Ott, J.; Quast, G.; Rabbertz, K.; Ratnikov, F.; Ratnikova, N.; Röcker, S.; Scheurer, A.; Schilling, F.-P.; Schott, G.; Simonis, H. J.; Stober, F. M.; Troendle, D.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weiler, T.; Zeise, M.; Daskalakis, G.; Geralis, T.; Kesisoglou, S.; Kyriakis, A.; Loukas, D.; Manolakos, I.; Markou, A.; Markou, C.; Mavrommatis, C.; Ntomari, E.; Gouskos, L.; Mertzimekis, T. J.; Panagiotou, A.; Saoulidou, N.; Evangelou, I.; Foudas, C.; Kokkas, P.; Manthos, N.; Papadopoulos, I.; Patras, V.; Bencze, G.; Hajdu, C.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Beni, N.; Czellar, S.; Molnar, J.; Palinkas, J.; Szillasi, Z.; Karancsi, J.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Beri, S. B.; Bhatnagar, V.; Dhingra, N.; Gupta, R.; Kaur, M.; Mehta, M. Z.; Nishu, N.; Saini, L. K.; Sharma, A.; Singh, J. B.; Kumar, Ashok; Kumar, Arun; Ahuja, S.; Bhardwaj, A.; Choudhary, B. C.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, V.; Shivpuri, R. K.; Banerjee, S.; Bhattacharya, S.; Dutta, S.; Gomber, B.; Jain, Sa.; Jain, Sh.; Khurana, R.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Choudhury, R. K.; Dutta, D.; Kailas, S.; Kumar, V.; Mehta, P.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Aziz, T.; Ganguly, S.; Guchait, M.; Maity, M.; Majumder, G.; Mazumdar, K.; Mohanty, G. B.; Parida, B.; Sudhakar, K.; Wickramage, N.; Banerjee, S.; Dugad, S.; Arfaei, H.; Bakhshiansohi, H.; Etesami, S. M.; Fahim, A.; Hashemi, M.; Hesari, H.; Jafari, A.; Khakzad, M.; Mohammadi Najafabadi, M.; Paktinat Mehdiabadi, S.; Safarzadeh, B.; Zeinali, M.; Abbrescia, M.; Barbone, L.; Calabria, C.; Chhibra, S. S.; Colaleo, A.; Creanza, D.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Lusito, L.; Maggi, G.; Maggi, M.; Marangelli, B.; My, S.; Nuzzo, S.; Pacifico, N.; Pompili, A.; Pugliese, G.; Selvaggi, G.; Silvestris, L.; Singh, G.; Venditti, R.; Zito, G.; Abbiendi, G.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Meneghelli, M.; Montanari, A.; Navarria, F. L.; Odorici, F.; Perrotta, A.; Primavera, F.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Travaglini, R.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Frosali, S.; Gallo, E.; Gonzi, S.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Tropiano, A.; Benussi, L.; Bianco, S.; Colafranceschi, S.; Fabbri, F.; Piccolo, D.; Fabbricatore, P.; Musenich, R.; Tosi, S.; Benaglia, A.; De Guio, F.; Di Matteo, L.; Fiorendi, S.; Gennai, S.; Ghezzi, A.; Malvezzi, S.; Manzoni, R. A.; Martelli, A.; Massironi, A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Ragazzi, S.; Redaelli, N.; Sala, S.; Tabarelli de Fatis, T.; Buontempo, S.; Carrillo Montoya, C. A.; Cavallo, N.; De Cosa, A.; Dogangun, O.; Fabozzi, F.; Iorio, A. O. M.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Azzi, P.; Bacchetta, N.; Bisello, D.; Branca, A.; Carlin, R.; Checchia, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Kanishchev, K.; Lacaprara, S.; Lazzizzera, I.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Vanini, S.; Zotto, P.; Zumerle, G.; Gabusi, M.; Ratti, S. P.; Riccardi, C.; Torre, P.; Vitulo, P.; Biasini, M.; Bilei, G. M.; Fanò, L.; Lariccia, P.; Lucaroni, A.; Mantovani, G.; Menichelli, M.; Nappi, A.; Romeo, F.; Saha, A.; Santocchia, A.; Spiezia, A.; Taroni, S.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Broccolo, G.; Castaldi, R.; D'Agnolo, R. T.; Dell'Orso, R.; Fiori, F.; Foà, L.; Giassi, A.; Kraan, A.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Serban, A. T.; Spagnolo, P.; Squillacioti, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Del Re, D.; Diemoz, M.; Fanelli, C.; Grassi, M.; Longo, E.; Meridiani, P.; Micheli, F.; Nourbakhsh, S.; Organtini, G.; Paramatti, R.; Rahatlou, S.; Sigamani, M.; Soffi, L.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Biino, C.; Cartiglia, N.; Costa, M.; De Remigis, P.; Demaria, N.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Musich, M.; Obertino, M. M.; Pastrone, N.; Pelliccioni, M.; Potenza, A.; Romero, A.; Sacchi, R.; Solano, A.; Staiano, A.; Vilela Pereira, A.; Belforte, S.; Candelise, V.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; Marone, M.; Montanino, D.; Penzo, A.; Schizzi, A.; Heo, S. G.; Kim, T. Y.; Nam, S. K.; Chang, S.; Kim, D. H.; Kim, G. N.; Kong, D. J.; Park, H.; Ro, S. R.; Son, D. C.; Son, T.; Kim, J. Y.; Kim, Zero J.; Song, S.; Choi, S.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, T. J.; Lee, K. S.; Moon, D. H.; Park, S. K.; Choi, M.; Kim, J. H.; Park, C.; Park, I. C.; Park, S.; Ryu, G.; Cho, Y.; Choi, Y.; Choi, Y. 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V.; Haas, J.; Hagopian, S.; Hagopian, V.; Jenkins, M.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Dorney, B.; Hohlmann, M.; Kalakhety, H.; Vodopiyanov, I.; Adams, M. R.; Anghel, I. M.; Apanasevich, L.; Bai, Y.; Bazterra, V. E.; Betts, R. R.; Bucinskaite, I.; Callner, J.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Khalatyan, S.; Lacroix, F.; Malek, M.; O'Brien, C.; Silkworth, C.; Strom, D.; Varelas, N.; Akgun, U.; Albayrak, E. A.; Bilki, B.; Clarida, W.; Duru, F.; Griffiths, S.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Newsom, C. R.; Norbeck, E.; Onel, Y.; Ozok, F.; Sen, S.; Tiras, E.; Wetzel, J.; Yetkin, T.; Yi, K.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Giurgiu, G.; Gritsan, A. V.; Guo, Z. J.; Hu, G.; Maksimovic, P.; Rappoccio, S.; Swartz, M.; Whitbeck, A.; Baringer, P.; Bean, A.; Benelli, G.; Grachov, O.; Kenny, R. 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S.; Grothe, M.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Klukas, J.; Lanaro, A.; Lazaridis, C.; Leonard, J.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Palmonari, F.; Pierro, G. A.; Ross, I.; Savin, A.; Smith, W. H.; Swanson, J.
2012-12-01
Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5fb-1 recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about ±20GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.
CHIRAL LIMIT AND LIGHT QUARK MASSES IN 2+1 FLAVOR DOMAIN WALL QCD.
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.
Top quark physics: Future measurements
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.
Quark flavor identification in electron-positron annihilation
Kaye, H.S.
1983-09-01
The theoretical issues relevant to inclusive muon analysis, the MAC detector and its data flow structure, the identification of muons in hadronic events and the measurement of their momenta, and the selection of events so as to minimize background are described. Experimental results are presented describing the fragmentation of heavy quarks into hadrons, the semimuonic branching fractions of the heavy quarks, the asymmetry in the angular distribution of the heavy quarks, and the invariant mass and charged multiplicity of heavy quark jets. In addition, lower limits are set on the masses of certain proposed particles that are expected to decay semileptonically. Finally, events containing two muons are analyzed in order to investigate the possibility of mixing in the B-B system and whether the b might form its own SU(2) singlet.
Limit on the B0 to rho0rho0 Branching Fraction and Implications for the CKM Angle alpha
Aubert, B.
2005-01-03
The authors search for the decay B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} in a data sample of about 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find no significant signal and set an upper limit of 1.1 x 10{sup -6} at 90% CL on the branching fraction. As a result, the uncertainty due to penguin contributions on the CKM unitarity angle {alpha} measured in B {yields} {rho}{rho} decays is 11{sup o} at 68% CL.
Fermion masses, flavour mixing and CP violation
Ross, G. G.
2008-11-23
The pattern of neutrino masses and mixings is characteristically different from those observed in the quark sector. I discuss how this can be elegantly explaned through a combination of an underlying family symmetry and the see-saw mechanism.
Quark Contributions to Nucleon Momentum and Spin from Domain Wall fermion calculations
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.
A measurement of quark and gluon jet differences at the Z{sup 0} resonance
Iwasaki, Yoshihito
1994-08-01
The authors have studied differences between quark and gluon jets using 3-jet events in hadronic decays of Z{sup 0} bosons collected by the SLD experiment at SLAC. Gluon jets were identified in symmetric 3-jet events containing one jet tagged as a heavy quark jet and compared with a mixed sample of quark and gluon jets and also with a mixed sample of light quark (u, d and s) and gluon jets. Their preliminary results show that the particle multiplicity in gluon jets is higher than that in light quark jets. These results are in qualitative agreement with QCD expectations. Differences are also observed in particle energy spectra and the jet widths, consistent with QCD expectations.
From quark drops to quark stars. Some aspects of the role of quark matter in compact stars
NASA Astrophysics Data System (ADS)
Lugones, Germán
2016-03-01
We review some recent results about the mechanism of deconfinement of hadronic matter into quark matter in cold neutron stars and protoneutron stars. We discuss the role of finite-size effects and the relevance of temperature and density fluctuations on the nucleation process. We also examine the importance of surface effects for mixed phases in hybrid stars. A small drop of quark matter nucleated at the core of a compact star may grow if the conversion is sufficiently exothermic. In such a case, it may trigger the burning of the stellar core and even the whole star if quark matter is absolutely stable. We explore the physical processes that occur inside the flame and analyze the hydrodynamic evolution of the combustion front. In the last part of this review, we focus on hybrid stars using the Nambu-Jona-Lasinio (NJL) model with scalar, vector and 't Hooft interactions, paying particular attention to a generalized non-standard procedure for the choice of the "bag constant". We also describe the non-radial oscillation modes of hadronic, hybrid and strange stars with maximum masses above 2M_{odot} and show that the frequency of the p1 and g fluid modes contains key information about the internal composition of compact objects.
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.
Nucleon quark distributions in a covariant quark-diquark model
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.
NASA Astrophysics Data System (ADS)
Vainshtein, Arkady
2011-04-01
Anomalous quark triangles with one axial and two vector currents are studied in special kinematics when one of the vector currents carries a soft momentum. According to the Adler-Bardeen theorem the anomalous longitudinal part of the triangle is not renormalized in the chiral limit. We show that perturbative corrections the transversal part of the triangle is also absent. This nonrenormalization, in difference with the longitudinal part, holds on only perturbatively.
NASA Astrophysics Data System (ADS)
Kane, Gordon L.; Perry, Malcolm J.
2015-03-01
We are used to thinking of quarks as fundamental particles in the same way we think of the electron, or gauge bosons, neutrinos, leptons. In strong theory, these objects are unified with gravitation and the physics of spacetime into what is hoped to be an ultimate theory, string/M theory. The string/M theory paradigm completely changes the way we think of the socalled elementary particles in quantum field theory.
NASA Astrophysics Data System (ADS)
Kane, Gordon L.; Perry, Malcolm J.
2015-01-01
We are used to thinking of quarks as fundamental particles in the same way we think of the electron, or gauge bosons, neutrinos, leptons. In strong theory, these objects are unified with gravitation and the physics of spacetime into what is hoped to be an ultimate theory, string/M theory. The string/M theory paradigm completely changes the way we think of the so-called elementary particles in quantum field theory.
Quark lepton complementarity and renormalization group effects
Schmidt, Michael A.; Smirnov, Alexei Yu.
2006-12-01
We consider a scenario for the quark-lepton complementarity relations between mixing angles in which the bimaximal mixing follows from the neutrino mass matrix. According to this scenario in the lowest order the angle {theta}{sub 12} is {approx}1{sigma} (1.5 degree sign -2 degree sign ) above the best fit point coinciding practically with the tribimaximal mixing prediction. Realization of this scenario in the context of the seesaw type-I mechanism with leptonic Dirac mass matrices approximately equal to the quark mass matrices is studied. We calculate the renormalization group corrections to {theta}{sub 12} as well as to {theta}{sub 13} in the standard model (SM) and minimal supersymmetric standard model (MSSM). We find that in a large part of the parameter space corrections {delta}{theta}{sub 12} are small or negligible. In the MSSM version of the scenario, the correction {delta}{theta}{sub 12} is in general positive. Small negative corrections appear in the case of an inverted mass hierarchy and opposite CP parities of {nu}{sub 1} and {nu}{sub 2} when leading contributions to {theta}{sub 12} running are strongly suppressed. The corrections are negative in the SM version in a large part of the parameter space for values of the relative CP phase of {nu}{sub 1} and {nu}{sub 2}: {phi}>{pi}/2.
Transversity quark distributions in a covariant quark-diquark model
I.C. Cloet; W. Bentz; A.W. Thomas
2008-01-01
Transversity quark light-cone momentum distributions 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 relativistic Faddeev equation in the quark-diquark approximation, where both scalar and axial-vector diquark channels are included. Particular attention is paid to comparing our results with the recent experimental extraction of the transversity distributions by Anselmino et al. We also compare our transversity results with earlier spin-independent and helicity quark distributions calculated in the same approach.
String worldsheet for accelerating quark
NASA Astrophysics Data System (ADS)
Hubeny, Veronika E.; Semenoff, Gordon W.
2015-10-01
We consider the AdS bulk dual to an external massive quark in SYM following an arbitrary trajectory on Minkowski background. While a purely outgoing boundary condition on the gluonic field allows one to express the corresponding string worldsheet in a closed form, the setup has curious consequences. In particular, we argue that any quark whose trajectory on flat spacetime approaches that of a light ray in the remote past (as happens e.g. in the case of uniform acceleration) must necessarily be accompanied by an anti-quark. This is puzzling from the field theory standpoint, since one would expect that a sole quark following any timelike trajectory should be allowed. We explain the resolution in terms of boundary and initial conditions. We analyze the configuration in global AdS, which naturally suggests a modification to the boundary conditions allowing for a single accelerated quark without accompanying anti-quark. We contrast this resolution with earlier proposals.
Measurements of heavy quark and lepton lifetimes
Jaros, J.A.
1985-02-01
The PEP/PETRA energy range has proved to be well-suited for the study of the lifetimes of hadrons containing the b and c quarks and the tau lepton for several reasons. First, these states comprise a large fraction of the total interaction rate in e/sup +/e/sup -/ annihilation and can be cleanly identified. Second, the storage rings have operated at high luminosity and so produced these exotic states copiously. And finally, thanks to the interplay of the Fermi coupling strength, the quark and lepton masses, and the beam energy, the expected decay lengths are in the 1/2 mm range and so are comparatively easy to measure. This pleasant coincidence of cleanly identified and abundant signal with potentially large effects has made possible the first measurements of two fundamental weak couplings, tau ..-->.. nu/sub tau/W and b ..-->.. cW. These measurements have provided a sharp test of the standard model and allowed, for the first time, the full determination of the magnitudes of the quark mixing matrix. This paper reviews the lifetime studies made at PEP during the past year. It begins with a brief review of the three detectors, DELCO, MAC and MARK II, which have reported lifetime measurements. Next it discusses two new measurements of the tau lifetime, and briefly reviews a measurement of the D/sup 0/ lifetime. Finally, it turns to measurements of the B lifetime, which are discussed in some detail. 18 references, 14 figures, 1 table.
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).
Statistical understanding of quark and lepton masses in Gaussian landscapes
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.
Quark matter or new particles?
NASA Technical Reports Server (NTRS)
Michel, F. Curtis
1988-01-01
It has been argued that compression of nuclear matter to somewhat higher densities may lead to the formation of stable quark matter. A plausible alternative, which leads to radically new astrophysical scenarios, is that the stability of quark matter simply represents the stability of new particles compounded of quarks. A specific example is the SU(3)-symmetric version of the alpha particle, composed of spin-zero pairs of each of the baryon octet (an 'octet' particle).
NASA Astrophysics Data System (ADS)
Antinori, Federico; Bass, Steffen A.; Bellwied, Rene; Ullrich, Thomas; Velkovska, Julia; Wiedemann, Urs
2005-04-01
Why another conference devoted to ultra-relativistic heavy-ion physics? As we looked around the landscape of the existing international conferences and workshops, we realized that there was not a single one tailored to the people who are most directly involved with the actual research work: students, post-docs, and junior faculty/research scientists. Of course there are schools, but that was not what we had in mind. We wanted a meeting where young researchers could come together to discuss in depth the physics that they are working on without any hindrance. The major conferences have very limited time for discussions which is often shared amongst the most established. This leaves little room for young people to ask their questions and to get the detailed feedback which they deserve and which satisfies their curiosity. A discussion-driven workshop, centering on those without whom there will be no future—that seemed like what was needed. And thus the Hot Quarks workshop was born. The aim of Hot Quarks was to enhance the direct exchange of scientific information among the younger members of the community, from both experiment and theory. Participation was by invitation only in order to emphasize the contributions from junior researchers. This approach makes the workshop unique among the many forums in the field. For young scientists it represented an opportunity for exposure that they would not have had in one of the major conferences. The hope is that this meeting has helped to stimulate the next generation of scientists in our field and, at the same time, strengthened their sense of community. It all came together from 18 24 July 2004, when the 77 participants met at The Inn at Snakedance in the Taos Ski Valley, New Mexico, USA, for the first Hot Quarks workshop. Photograph Participants gather in the sunshine at the foot of the Taos Ski Valley chairlift. By all accounts, Hot Quarks 2004 was a great success. Every participant had the opportunity to present her or
Valence quark spin distribution functions
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''.
Eric S. Swanson; Adam P. Szczepaniak
2002-06-07
The relationship of the quark model to the known chiral properties of QCD is a long-standing problem in the interpretation of low energy QCD. In particular, how can the pion be viewed as both a collective Goldstone boson quasiparticle and as a valence quark antiquark bound state? A comparison of the many-body solution of a simplified model of QCD to the constituent quark model demonstrates that the quark model is sufficiently flexible to describe meson hyperfine splitting provided proper renormalization conditions and correct degrees of freedom are employed consistently.
Potamianos, Karolos
2011-12-01
We present the recent results of top-quark physics using up to 6 fb{sup -1} of p{bar p} collisions analyzed by the CDF collaboration. The large number of top quark events analyzed, of the order of several thousands, allows stringent checks of the standard model predictions. Also, the top quark is widely believed to be a window to new physics. We present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.
Exotic quarks in Twin Higgs models
NASA Astrophysics Data System (ADS)
Cheng, Hsin-Chia; Jung, Sunghoon; Salvioni, Ennio; Tsai, Yuhsin
2016-03-01
The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ˜ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. Depending on the details of the twin sector, the exotic quarks may be probed up to ˜ 2.5TeV at the LHC and beyond 10TeV at a future 100TeV collider, providing a strong test of this class of ultraviolet completions.
Exotic quarks in Twin Higgs models
Cheng, Hsin -Chia; Jung, Sunghoon; Salvioni, Ennio; Tsai, Yuhsin
2016-03-14
The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of themore » model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. As a result, depending on the details of the twin sector, the exotic quarks may be probed up to ~ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.« less
Anzelc, Meghan
2008-06-01
B$0\\atop{s}$ mixing studies provide a precision test of Charge-Parity violation in the Standard Model. A measurement of Δm_{s} constrains elements of the CKM quark rotation matrix [1], providing a probe of Standard Model Charge-Parity violation. This thesis describes a study of B$0\\atop{s}$ mixing in the semileptonic decay B$0\\atop{s}$ → D_{s}^{-} μ^{+}vX, where D_{s}^{-} → Φπ^{-}, using data collected at the D-Zero detector at Fermi National Accelerator in Batavia, Illinois. Approximately 2.8 fb^{-1} of data collected between April 2002 and August 2007 was used, covering the entirety of the Tevatron's RunIIa (April 2002 to March 2006) and part of RunIIb (March 2006-August 2007). Taggers using both opposite-side and same-side information were used to obtain the flavor information of the B_{s}^{0} meson at production. The charge of the muon in the decay B$0\\atop{s}$ → D_{s}^{-}μ^{+}vX was used to determine the flavor of the B$0\\atop{s}$ at decay. The B$d\\atop{0}$ mixing frequency, Δm_{d}, was measured to verify the analysis procedure. A log-likelihood calculation was performed, and a measurement of Δm_{s} was obtained. The final result was Δm_{s} = 18.86 ± 0.80(stat.) ± 0.37(sys.) with a significance of 2.6σ.
Quark and Gluon Relaxation in Quark-Gluon Plasmas
NASA Technical Reports Server (NTRS)
Heiselberg, H.; Pethick, C. J.
1993-01-01
The quasiparticle decay rates for quarks and gluons in quark-gluon plasmas are calculated by solving the kinetic equation. Introducing an infrared cutoff to allow for nonperturbative effects, we evaluate the quasiparticle lifetime at momenta greater than the inverse Debye screening length to leading order in the coupling constant.
The Discovery of the Top Quark
DOE R&D Accomplishments Database
Sinervo, P.K.
1995-12-01
The top quark and the Higgs boson are the heaviest elementary particles predicted by the standard model. The four lightest quark flavours, the up, down, strange and charm quarks, were well-established by the mid-1970's. The discovery in 1977 of the {Tau} resonances, a new family of massive hadrons, required the introduction of the fifth quark flavour. Experimental and theoretical studies have indicated that this quark also has a heavier partner, the top quark.
Lincoln, Don
2015-05-07
Matter is malleable and can change its properties with temperature. This is most familiar when comparing ice, liquid water and steam, which are all different forms of the same thing. However beyond the usual states of matter, physicists can explore other states, both much colder and hotter. In this video, Fermilab’s Dr. Don Lincoln explains the hottest known state of matter – a state that is so hot that protons and neutrons from the center of atoms can literally melt. This form of matter is called a quark gluon plasma and it is an important research topic being pursued at the LHC.
NASA Astrophysics Data System (ADS)
Kurkela, Aleksi; Vuorinen, Aleksi
2016-07-01
We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O (g5) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium.
Kurkela, Aleksi; Vuorinen, Aleksi
2016-07-22
We generalize the state-of-the-art perturbative equation of state of cold quark matter to nonzero temperatures, needed in the description of neutron star mergers and core collapse processes. The new result is accurate to O(g^{5}) in the gauge coupling, and is based on a novel framework for dealing with the infrared sensitive soft field modes of the theory. The zero Matsubara mode sector is treated via a dimensionally reduced effective theory, while the soft nonzero modes are resummed using the hard thermal loop approximation. This combination of known effective descriptions offers unprecedented access to small but nonzero temperatures, both in and out of beta equilibrium. PMID:27494468
Top quark physics: Future Measurements
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.
Quaternion family symmetry of quarks and leptons
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.
Phenomenology of heavy quark production
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.
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.
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.
Nakamura, Koji
2009-02-01
Top quarks are predominantly produced in pairs via the strong interaction in $\\bar{p}$p collisions at √s = 1.96 TeV . The top quark has a weak isospin 1/2, composing a weak isospin doublet with the bottom quark. This characteristic predicts not only top quark pair production via strong interaction but also single production together with a bottom quark via weak interaction. However, finding single top quark production is challenging since it is rarely produced (σ _{singletop} = 2.9 pb) against background processes with the same final state like W+jets and t$\\bar{t}$. A measurement of electroweak single top production probes the W-t-b vertex, which provides a direct determination of the Cabbibo-Kobayashi-Maskawa (CKM) matrix element |V_{tb}|. The sample offers a source of almost 100% polarized top quarks. This thesis describes an optimized search for s-channel single top quark production and a measurement of the single top production cross section using 2.7 fb^{-1} of data accumulated with the CDF detector. We are using events with one high-p_{T} lepton, large missing E_{T} and two identified b-quark jets where one jet is identified using a secondary vertex tagger, called SecVtx, and the other jet is identified using SecVtx or a jet probability tagger, called JetProb. In this analysis we have developed a kinematics fitter and a likelihood-based separator between signal and background. As a result, we found that the probability (p-value) that the candidate events originate from a background fluctuation in the absence of single top s-channel production is 0.003, which is equivalent to 2.7 σ deviations in Gaussian statistics, and this excess corresponds to the single top s-channel cross section of 2.38_{-0.84}^{+1.01} pb. An observed value of |V_{tb}| is 1.43_{-0.26}^{+0.38}(experimental) ± 0.11(theory). We also set the 95% CL. upper limit of σ_{s} = 4.15 pb for the s
Schramm, D.N. |; Fields, B.; Thomas, D.
1992-01-01
The possible implications of the quark-hadron transition for cosmology are explored. Possible surviving signatures are discussed. In particular, the possibility of generating a dark matter candidate such as strange nuggets or planetary mass black holes is noted. Much discussion is devoted to the possible role of the transition for cosmological nucleosynthesis. It is emphasized that even an optimized first order phase transition will not significantly alter the nucleosynthesis constraints on the cosmological baryon density nor on neutrino counting. However, it is noted that Be and B observations in old stars may eventually be able to be a signature of a cosmologically significant quark-hadron transition. It is pointed out that the critical point in this regard is whether the observed B/Be ratio can be produced by spallation processes or requires cosmological input. Spallation cannot produce a B/Be ratio below 7.6. A supporting signature would be Be and B ratios to oxygen that greatly exceed galactic values. At present, all data is still consistent with a spallagenic origin.
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}.
STRANGE GOINGS ON IN QUARK MATTER.
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.
NASA Astrophysics Data System (ADS)
Alam, Jan-e.; Chattopadhyay, Subhasis; Nayak, Tapan; Sinha, Bikash; Viyogi, Yogendra P.
2008-10-01
Quark Matter 2008—the 20th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions was held in Jaipur, the Pink City of India, from 4-10 February, 2008. Organizing Quark Matter 2008 in India itself indicates the international recognition of the Indian contribution to the field of heavy-ion physics, which was initiated and nurtured by Bikash Sinha, Chair of the conference. The conference was inaugurated by the Honourable Chief Minister of Rajasthan, Smt. Vasundhara Raje followed by the key note address by Professor Carlo Rubbia. The scientific programme started with the theoretical overview, `SPS to RHIC and onwards to LHC' by Larry McLerran followed by several theoretical and experimental overview talks on the ongoing experiments at SPS and RHIC. The future experiments at the LHC, FAIR and J-PARC, along with the theoretical predictions, were discussed in great depth. Lattice QCD predictions on the nature of the phase transition and critical point were vigorously debated during several plenary and parallel session presentations. The conference was enriched by the presence of an unprecedented number of participants; about 600 participants representing 31 countries across the globe. This issue contains papers based on plenary talks and oral presentations presented at the conference. Besides invited and contributed talks, there were also a large number of poster presentations. Members of the International Advisory Committee played a pivotal role in the selection of speakers, both for plenary and parallel session talks. The contributions of the Organizing Committee in all aspects, from helping to prepare the academic programme down to arranging local hospitality, were much appreciated. We thank the members of both the committees for making Quark Matter 2008 a very effective and interesting platform for scientific deliberations. Quark Matter 2008 was financially supported by: Air Liquide (New Delhi) Board of Research Nuclear Sciences (Mumbai) Bose
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)
Quark flavour observables in the Littlest Higgs model with T-parity after LHC Run 1
NASA Astrophysics Data System (ADS)
Blanke, Monika; Buras, Andrzej J.; Recksiegel, Stefan
2016-04-01
The Littlest Higgs model with T-parity (LHT) belongs to the simplest new physics scenarios with new sources of flavour and CP violation. The latter originate in the interactions of ordinary quarks and leptons with heavy mirror quarks and leptons that are mediated by new heavy gauge bosons. Also a heavy fermionic top partner is present in this model which communicates with the SM fermions by means of standard W^± and Z^0 gauge bosons. We present a new analysis of quark flavour observables in the LHT model in view of the oncoming flavour precision era. We use all available information on the CKM parameters, lattice QCD input and experimental data on quark flavour observables and corresponding theoretical calculations, taking into account new lower bounds on the symmetry breaking scale and the mirror quark masses from the LHC. We investigate by how much the branching ratios for a number of rare K and B decays are still allowed to depart from their SM values. This includes K^+→ π ^+ν bar{ν }, KL→ π ^0ν bar{ν }, K_L→ μ ^+μ ^-, B→ X_sγ , B_{s,d}→ μ ^+μ ^-, B→ K^{(*)}ℓ ^+ℓ ^-, B→ K^{(*)}ν bar{ν }, and \\varepsilon '/\\varepsilon . Taking into account the constraints from Δ F=2 processes, significant departures from the SM predictions for K^+→ π ^+ν bar{ν } and KL→ π ^0ν bar{ν } are possible, while the effects in B decays are much smaller. In particular, the LHT model favours B(Bs→ μ ^+μ ^-) ≥ B(Bs→ μ ^+μ ^-)_SM, which is not supported by the data, and the present anomalies in B→ K^{(*)}ℓ ^+ℓ ^- decays cannot be explained in this model. With the recent lattice and large N input the imposition of the \\varepsilon '/\\varepsilon constraint implies a significant suppression of the branching ratio for KL→ π ^0ν bar{ν } with respect to its SM value while allowing only for small modifications of K^+→ π ^+ν bar{ν }. Finally, we investigate how the LHT physics could be distinguished from other models by means of
Observation of Electroweak Single Top-Quark Production with the CDF II Experiment
Lueck, Jan
2009-07-24
The standard model of elementary particle physics (SM) predicts, besides the top-quark pair production via the strong interaction, also the electroweak production of single top-quarks [19]. Up to now, the Fermilab Tevatron proton-antiproton-collider is the only place to produce and study top quarks emerging from hadron-hadron-collisions. Top quarks were directly observed in 1995 during the Tevatron Run I at a center-of-mass energy of √s = 1.8 TeV simultaneously by the CDF and D0 Collaborations via the strong production of top-quark pairs. Run II of the Tevatron data taking period started 2001 at √s = 1.96 TeV after a five year upgrade of the Tevatron accelerator complex and of both experiments. One main component of its physics program is the determination of the properties of the top quark including its electroweak production. Even though Run II is still ongoing, the study of the top quark is already a successful endeavor, confirmed by dozens of publications from both Tevatron experiments. A comprehensive review of top-quark physics can be found in reference. The reasons for searching for single top-quark production are compelling. As the electroweak top-quark production proceeds via a Wtb vertex, it provides the unique opportunity of the direct measurement of the CKM matrix element |V_{tb}|, which is expected to be |V_{tb}| ~ 1 in the SM. Significant deviations from unity could be an indication of a fourth quark generation, a production mode via flavor-changing neutral currents, and other new phenomena, respectively. There are two dominating electroweak top-quark production modes at the Fermilab Tevatron: the t-channel exchange of a virtual W boson striking a b quark and the s-channel production of a timelike W boson via the fusion of two quarks. In proton-antiproton-collisions the third electroweak production mode, the associated Wt production of an on-shell W boson in conjunction with a top quark has a comparatively negligible small
Melting hadrons, boiling quarks
NASA Astrophysics Data System (ADS)
Rafelski, Johann
2015-09-01
In the context of the Hagedorn temperature half-centenary I describe our understanding of the hot phases of hadronic matter both below and above the Hagedorn temperature. The first part of the review addresses many frequently posed questions about properties of hadronic matter in different phases, phase transition and the exploration of quark-gluon plasma (QGP). The historical context of the discovery of QGP is shown and the role of strangeness and strange antibaryon signature of QGP illustrated. In the second part I discuss the corresponding theoretical ideas and show how experimental results can be used to describe the properties of QGP at hadronization. The material of this review is complemented by two early and unpublished reports containing the prediction of the different forms of hadron matter, and of the formation of QGP in relativistic heavy ion collisions, including the discussion of strangeness, and in particular strange antibaryon signature of QGP.
Menzione, A.
1995-10-01
Most of the material presented in this report, comes from contributions to the parallel session PL20 of this conference. We summarise the experimental results of direct production of Top quarks, coming from the CDF and C0 Collaborations at Fermilab, and compare these results to what one expects within current theoretical understanding. Particular attention is given to new results such as all hadronic modes of t{bar t} decay. As far as the mass is concerned, a comparison is made with precision measurements of related quantities, coming from LEP and other experiments. An attempt is made to look at the medium-term future and understand which variables and with what accuracy one can measure them with increased integrated luminosity.
Quantifying zigzag motion of quarks
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.
Moed, Shulamit
2010-02-10
The large data samples of top quark candidate events collected at the Tevatron CDF II experiment allow for a variety of measurements to analyze the production of the top quark. This article discusses recent results of top quark production at CDF presented at the SUSY09 conference, including updates to the top pair production cross section, forward-backward asymmetry in tt-bar production, single top search, search for top resonances and a search for heavy top. The discussed measurements utilize up to 3.2 fb{sup -1} of integrated luminosity collected at CDF.
Moed, Shulamit; /Harvard U.
2010-01-01
The large data samples of top quark candidate events collected at the Tevatron CDF II experiment allow for a variety of measurements to analyze the production of the top quark. This article discusses recent results of top quark production at CDF presented at the SUSY09 conference, including updates to the top pair production cross section, forward-backward asymmetry in t{bar t} production, single top search, search for top resonances and a search for heavy top. The discussed measurements utilize up to 3.2 fb{sup -1} of integrated luminosity collected at CDF.
Ginsparg-Wilson pions scattering in a sea of staggered quarks
Chen, J.-W.; O'Connell, Donal; Van de Water, Ruth; Walker-Loud, Andre
2006-04-01
We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two-pion states in nonunitary theories such as partially quenched or mixed action QCD is identical to that of QCD. Thus one can extract infinite-volume scattering parameters from mixed action simulations. We then determine the scattering length for both 2 and 2+1 sea quarks in the isospin limit. The scattering length, when expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons, thus it does not depend upon the parameter, C{sub Mix}, that appears in the chiral Lagrangian of the mixed theory. In addition, the contributions which nominally arise from operators appearing in the mixed action O(a{sup 2}m{sub q}) Lagrangian exactly cancel when the scattering length is written in this form. This is in contrast to the scattering length expressed in terms of the bare parameters of the chiral Lagrangian, which explicitly exhibits all the sicknesses and lattice spacing dependence allowed by a partially quenched mixed action theory. These results hold for both 2 and 2+1 flavors of sea quarks.
Top quark studies at hadron colliders
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.
Heavy quarks in the jet calculus
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.
Top quark studies at hadron colliders
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.
Fermion masses and neutrino mixing in an SU(5)/sub GUT/ x SU(8)/sub ETC/ model
Aubrecht, G.J. II; Matsuki, T.; Tanaka, K.
1983-01-01
We extend the SU(3) x SU(2) x U(1) model without scalars to SU(5)/sub GUT/ x SU(8)/sub ETC/. In our model, the mixing in the leptons is identical to that for the quarks, so that the Cabibbo angle determines the mixing of nu/sub e/ and nu/sub ..mu../. The quark masses and mixing angles are studied for two and three generations of quarks.
Wicke, Daniel; /Wuppertal U., Dept. Math.
2009-08-01
The aim of particle physics is the understanding of elementary particles and their interactions. The current theory of elementary particle physics, the Standard Model, contains twelve different types of fermions which (neglecting gravity) interact through the gauge bosons of three forces. In addition a scalar particle, the Higgs boson, is needed for theoretical consistency. These few building blocks explain all experimental results found in the context of particle physics, so far. Nevertheless, it is believed that the Standard Model is only an approximation to a more complete theory. First of all the fourth known force, gravity, has withstood all attempts to be included until now. Furthermore, the Standard Model describes several features of the elementary particles like the existence of three families of fermions or the quantisation of charges, but does not explain these properties from underlying principles. Finally, the lightness of the Higgs boson needed to explain the symmetry breaking is difficult to maintain in the presence of expected corrections from gravity at high scales. This is the so called hierarchy problem. In addition astrophysical results indicate that the universe consists only to a very small fraction of matter described by the Standard Model. Large fractions of dark energy and dark matter are needed to describe the observations. Both do not have any correspondence in the Standard Model. Also the very small asymmetry between matter and anti-matter that results in the observed universe built of matter (and not of anti-matter) cannot be explained until now. It is thus an important task of experimental particle physics to test the predictions of the Standard Model to the best possible accuracy and to search for deviations pointing to necessary extensions or modifications of our current theoretical understanding. The top quark was predicted to exist by the Standard Model as the partner of the bottom quark. It was first observed in 1995 by the
Off-forward quark-quark correlation function
Casanova, Sabrina
2006-09-01
The properties of the nonforward quark-quark correlation function are examined. We derive constraints on the correlation function from the transformation properties of the fundamental fields of QCD occurring in its definition. We further develop a method to construct an Ansatz for this correlator. We present the complete leading order set of generalized parton distributions in terms of the amplitudes of the Ansatz. Finally we conclude that the number of independent generalized parton helicity changing distributions is four.
Anatomy of new physics in B-B mixing
Lenz, A.; Nierste, U.; Charles, J.; Descotes-Genon, S.; Kaufhold, C.; T'Jampens, S.; Lacker, H.; Monteil, S.; Niess, V.
2011-02-01
We analyze three different new physics scenarios for {Delta}F=2 flavor-changing neutral currents in the quark sector in the light of recent data on neutral-meson mixing. We parametrize generic new physics contributions to B{sub q}-B{sub q} mixing, q=d, s, in terms of one complex quantity {Delta}{sub q}, while three parameters {Delta}{sub K}{sup tt}, {Delta}{sub K}{sup ct}, and {Delta}{sub K}{sup cc} are needed to describe K-K mixing. In scenario I, we consider uncorrelated new physics contributions in the B{sub d}, B{sub s}, and K sectors. In this scenario, it is only possible to constrain the parameters {Delta}{sub d} and {Delta}{sub s} whereas there are no nontrivial constraints on the kaon parameters. In scenario II, we study the case of minimal flavor violation (MFV) and small bottom Yukawa coupling, where {Delta}{identical_to}{Delta}{sub d}={Delta}{sub s}={Delta}{sub K}{sup tt}. We show that {Delta} must then be real, so that no new CP phases can be accommodated, and express the remaining parameters {Delta}{sub K}{sup cc} and {Delta}{sub K}{sup ct} in terms of {Delta} in this scenario. Scenario III is the generic MFV case with large bottom Yukawa couplings. In this case, the kaon sector is uncorrelated to the B{sub d} and B{sub s} sectors. As in the second scenario one has {Delta}{sub d}={Delta}{sub s{identical_to}{Delta}}, however, now with a complex parameter {Delta}. Our quantitative analyses consist of global Cabibbo-Kobayashi-Maskawa (CKM) fits within the Rfit frequentist statistical approach, determining the standard model parameters and the new physics parameters of the studied scenarios simultaneously. We find that the recent measurements indicating discrepancies with the standard model are well accommodated in Scenarios I and III with new mixing phases, with a slight preference for Scenario I that permits different new CP phases in the B{sub d} and B{sub s} systems. Within our statistical framework, we find evidence of new physics in both B{sub d} and
Gronek, Piotr; Holdys, Joanna; Kryściak, Jakub; Stanisławski, Daniel
2013-01-01
The search for genes with a positive influence on physical fitness is a difficult process. Physical fitness is a trait determined by multiple genes, and its genetic basis is then modified by numerous environmental factors. The present study examines the effects of the polymorphism of creatine kinase (CKM) gene on VO2max – a physiological index of aerobic capacity of high heritability. The study sample consisted of 154 men and 85 women, who were students of the University School of Physical Education in Poznań and athletes practicing various sports, including members of the Polish national team. The study revealed a positive effect of a rare G (NcoI−) allele of the CKM gene on maximal oxygen uptake in Caucasian women practicing sports requiring aerobic and anaerobic exercise metabolism. Also a tendency was noted in individuals with NcoI−/− (GG) and NcoI−/+ (GA) genotypes to reach higher VO2max levels. PMID:24511349
Quark-lepton flavor democracy and the nonexistence of the fourth generation
NASA Astrophysics Data System (ADS)
Cvetič, G.; Kim, C. S.
1995-01-01
In the standard model with two Higgs doublets (type II), which has a consistent trend to a flavor gauge theory and its related flavor democracy in the quark and the leptonic sectors (unlike the minimal standard model) when the energy of the probes increases, we impose the mixed quark-lepton flavor democracy at high ``transition'' energy and assume the usual seesaw mechanism, and consequently find out that the existence of the fourth generation of fermions in this framework is practically ruled out.
Quark-lepton flavor democracy and the nonexistence of the fourth generation
Cvetic, G. ); Kim, C.S. )
1995-01-01
In the standard model with two Higgs doublets (type II), which has a consistent trend to a flavor gauge theory and its related flavor democracy in the quark and the leptonic sectors (unlike the minimal standard model) when the energy of the probes increases, we impose the mixed quark-lepton flavor democracy at high transition'' energy and assume the usual seesaw mechanism, and consequently find out that the existence of the fourth generation of fermions in this framework is practically ruled out.
NASA Astrophysics Data System (ADS)
Kobayashi, Makoto
2014-11-01
After a short review of the activities of Shoichi Sakata and his group, how the six-quark model explains CP violation is described. Experimental verification of the model at the B-factories is also briefly discussed.
Stability of Quark Star Models
NASA Astrophysics Data System (ADS)
M., Azam; S. A., Mardan; M. A., Rehman
2016-05-01
In this paper, we investigate the stability of quark stars with four different types of inner matter configurations; isotropic, charged isotropic, anisotropic and charged anisotropic by using the concept of cracking. For this purpose, we have applied local density perturbations technique to the hydrostatic equilibrium equation as well as on physical parameters involved in the model. We conclude that quark stars become potentially unstable when inner matter configuration is changed and electromagnetic field is applied.
Heavy quark production and spectroscopy
Appel, J.A.
1993-11-01
This review covers many new experimental results on heavy flavor production and spectroscopy. It also shows some of the increasingly improved theoretical understanding of results in light of basic perturbative QCD and heavy quark symmetry. At the same time, there are some remaining discrepancies among experiments as well as significant missing information on some of the anticipated lowest lying heavy quark states. Most interesting, perhaps, are some clearly measured production effects awaiting full explanation.
Ginsparg-Wilson pions scattering in a sea of staggered quarks
NASA Astrophysics Data System (ADS)
Chen, Jiunn-Wei; O'Connell, Donal; van de Water, Ruth; Walker-Loud, André
2006-04-01
We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two-pion states in nonunitary theories such as partially quenched or mixed action QCD is identical to that of QCD. Thus one can extract infinite-volume scattering parameters from mixed action simulations. We then determine the scattering length for both 2 and 2+1 sea quarks in the isospin limit. The scattering length, when expressed in terms of the pion mass and the decay constant measured on the lattice, has no contributions from mixed valence-sea mesons, thus it does not depend upon the parameter, CMix, that appears in the chiral Lagrangian of the mixed theory. In addition, the contributions which nominally arise from operators appearing in the mixed action O(a2mq) Lagrangian exactly cancel when the scattering length is written in this form. This is in contrast to the scattering length expressed in terms of the bare parameters of the chiral Lagrangian, which explicitly exhibits all the sicknesses and lattice spacing dependence allowed by a partially quenched mixed action theory. These results hold for both 2 and 2+1 flavors of sea quarks.
High scale mixing unification for Dirac neutrinos
NASA Astrophysics Data System (ADS)
Abbas, Gauhar; Gupta, Saurabh; Rajasekaran, G.; Srivastava, Rahul
2015-06-01
Starting with the high scale mixing unification hypothesis, we investigate the renormalization-group evolution of mixing parameters and masses for Dirac-type neutrinos. Following this hypothesis, the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing angles and phase are taken to be identical to the Cabibbo-Kobayashi-Maskawa (CKM) ones at a unifying high scale. Then they are evolved to a low scale using renormalization-group equations. The notable feature of this hypothesis is that renormalization-group evolution with quasidegenerate mass pattern can explain largeness of leptonic mixing angles even for Dirac neutrinos. The renormalization-group evolution "naturally" results in a nonzero and small value of leptonic mixing angle θ13. One of the important predictions of this work is that the mixing angle θ23 is nonmaximal and lies only in the second octant. We also derive constraints on the allowed parameter range for the supersymmetry breaking and unification scales for which this hypothesis works. The results are novel and can be tested by present and future experiments.
Hyperon puzzle, hadron-quark crossover and massive neutron stars
NASA Astrophysics Data System (ADS)
Masuda, Kota; Hatsuda, Tetsuo; Takatsuka, Tatsuyuki
2016-03-01
Bulk properties of cold and hot neutron stars are studied on the basis of the hadron-quark crossover picture where a smooth transition from the hadronic phase to the quark phase takes place at finite baryon density. By using a phenomenological equation of state (EOS) "CRover", which interpolates the two phases at around 3 times the nuclear matter density (ρ0, it is found that the cold NSs with the gravitational mass larger than 2M_{odot} can be sustained. This is in sharp contrast to the case of the first-order hadron-quark transition. The radii of the cold NSs with the CRover EOS are in the narrow range (12.5 ± 0.5) km which is insensitive to the NS masses. Due to the stiffening of the EOS induced by the hadron-quark crossover, the central density of the NSs is at most 4 ρ0 and the hyperon-mixing barely occurs inside the NS core. This constitutes a solution of the long-standing hyperon puzzle. The effect of color superconductivity (CSC) on the NS structures is also examined with the hadron-quark crossover. For the typical strength of the diquark attraction, a slight softening of the EOS due to two-flavor CSC (2SC) takes place and the maximum mass is reduced by about 0.2M_{odot}. The CRover EOS is generalized to the supernova matter at finite temperature to describe the hot NSs at birth. The hadron-quark crossover is found to decrease the central temperature of the hot NSs under isentropic condition. The gravitational energy release and the spin-up rate during the contraction from the hot NS to the cold NS are also estimated.
Possible evidence for the breakdown of the CKM-paradigm of CP-violation
Soni, A.; Lunghi, E
2011-03-14
Using primarily experimental inputs for S(B{sub d} {yields} {psi} K{sub s}), {Delta}M{sub B{sub s}}, {Delta}M{sub B{sub d}}, BR (B {yields} {tau}{nu}) and {epsilon}{sub K} along with necessary inputs from the lattice, we find that the measured value of sin(2{beta}) is smaller than expectations of the Standard Model by as much as 3.3 {sigma}, and also that the measured value of the BR(B {yields} {tau}{nu}) seems to be less than the predicted value by about 2.8 {sigma}. However, through a critical study we show that most likely the dominant source of these deviations is in B{sub d(s)} mixings and in sin(2{beta}) and less so in B {yields} {tau}{nu}, and also that the bulk of the problem persists even if input from {epsilon}{sub K} is not used. The fact that kaon mixing and {epsilon}{sub K} are not the dominant source of the deviation from the Standard Model has the very important consequence that model independent considerations imply that the scale of the relevant new CP-violating physics is below O(2 TeV), and possibly even a few hundred GeVs, thus suggesting that direct signals of the new particle(s) may well be accessible in collider experiments at the LHC and perhaps even at the Tevatron.
Top quark compositeness: Feasibility and implications
Pomarol, Alex; Serra, Javi
2008-10-01
In models of electroweak symmetry breaking in which the standard model fermions get their masses by mixing with composite states, it is natural to expect the top quark to show properties of compositeness. We study the phenomenological viability of having a mostly composite top. The strongest constraints are shown to mainly come from one-loop contributions to the T parameter. Nevertheless, the presence of light custodial partners weakens these bounds, allowing in certain cases for a high degree of top compositeness. We find regions in the parameter space in which the T parameter receives moderate positive contributions, favoring the electroweak fit of this type of model. We also study the implications of having a composite top at the LHC, focusing on the process pp{yields}tttt(bb) whose cross section is enhanced at high energies.
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.
Nuclear matter from effective quark-quark interaction.
Baldo, M; Fukukawa, K
2014-12-12
We study neutron matter and symmetric nuclear matter with the quark-meson model for the two-nucleon interaction. The Bethe-Bruckner-Goldstone many-body theory is used to describe the correlations up to the three hole-line approximation with no extra parameters. At variance with other nonrelativistic realistic interactions, the three hole-line contribution turns out to be non-negligible and to have a substantial saturation effect. The saturation point of nuclear matter, the compressibility, the symmetry energy, and its slope are within the phenomenological constraints. Since the interaction also reproduces fairly well the properties of the three-nucleon system, these results indicate that the explicit introduction of the quark degrees of freedom within the considered constituent quark model is expected to reduce the role of three-body forces. PMID:25541769
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
Searches for new quarks and leptons in Z boson decays
Van Kooten, R.J.
1990-06-01
Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLAC Linear Collider operating in the center-of-mass energy range from 89.2 to 93.0 GeV. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fermions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge--1/3(b{prime}) quarks are made considering a variety of possible standard and non-standard decay modes. In addition, searches for sequential fourth generation massive neutrinos {nu}{sub 4} and their charged lepton partners L{sup {minus}} are pursued. The {nu}{sub 4} may be stable or decay through mixing to the lighter generations. The data sample is examined for new particle topologies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c{sup 2} for the top quark and 42.0 GeV/c{sup 2} for the b{prime}-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of {nu}{sub 4} to other generation neutrinos for a {nu}{sub 4} mass from 1 GeV/c{sup 2} to 43 GeV/c{sup 2} is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the {nu}{sub 4} mass and mixing matrix elements, and also permit the exclusion of a region in the L{sup {minus}} mass versus {nu}{sub 4} mass plane.