NASA Astrophysics Data System (ADS)
Hovdebo, Jordan L.; Kruczenski, Martín; Mateos, David; Myers, Robert C.; Winters, David J.
We study mesons in an {N} = 2 super Yang-Mills theory with fundamental matter from its dual string theory on AdS5 × S5 with a D7-brane probe. For quarks with a finite mass mq, the meson spectrum is discrete and exhibits a mass gap of order mq/√ {g2YM N}. The spectrum of mesons with large spin J is obtained from semiclassical rotating open strings attached to the D7-brane. It displays Regge behaviour for J << √ {g2YM N} whereas for J >> √ {g2YM N} it corresponds to that of two non-relativistic quarks bound by a Coulomb potential. We calculate
Meson-meson interactions and Regge propagators
Beveren, Eef van Rupp, George
2009-08-15
By a reformulation of the loop expansion in the Resonance-Spectrum Expansion amplitude for meson-meson scattering, in terms of s-channel exchange of families of propagator modes, we obtain a formalism which allows for a wider range of applications. The connection with the unitarized amplitudes employed in some chiral theories is discussed. We also define an alternative for the Regge spectra and indicate how this may be observed in experiment.
Barnes, T.
2001-04-26
This short contribution is a lite MESON2000 conference summary. As appropriate for the 600th anniversary of the Jagellonian University, it begins with a brief summary of the last 600 years of European history and its place in hadron physics. Next a ''physicist chirality'' order parameter PC is introduced. When applied to MESON2000 plenary speakers this order parameter illustrates the separation of hadron physicists into disjoint communities. The individual plenary talks in MESON2000 are next sorted according to the subconference associated with each of the 36 plenary speakers. Finally, I conclude with a previously unreported Feynman story regarding the use of models in hadron physics.
Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard
2009-05-01
A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.
ρ meson decays of heavy hybrid mesons
NASA Astrophysics Data System (ADS)
Zhang, Liang; Huang, Peng-Zhi
2016-07-01
We calculate the ρ meson couplings between the heavy hybrid doublets Hh/Sh/Mh/Th and the ordinary qQ̅ doublets in the framework of the light-cone QCD sum rule. The sum rules obtained rely mildly on the Borel parameters in their working regions. The resulting coupling constants are rather small in most cases. Supported by National Natural Science Foundation of China (11105007)
Liu Yunhu; Shao Jianxin; Wang Xiaogang; Zhang Ziying; Li Demin
2008-02-01
Based on the main assumption that the D{sub sJ}(2860) belongs to the 2{sup 3}P{sub 0} qq multiplet, the masses of the scalar meson nonet are estimated in the framework of the relativistic independent quark model, Regge phenomenology, and meson-meson mixing. We suggest that the a{sub 0}(1005), K{sub 0}*(1062), f{sub 0}(1103), and f{sub 0}(564) constitute the ground scalar meson nonet; it is supposed that these states would likely correspond to the observed states a{sub 0}(980), {kappa}(900), f{sub 0}(980), and f{sub 0}(600)/{sigma}, respectively. Also a{sub 0}(1516), K{sub 0}*(1669), f{sub 0}(1788), and f{sub 0}(1284) constitute the first radial scalar meson nonet, it is supposed that these states would likely correspond to the observed states a{sub 0}(1450), K{sub 0}*(1430), f{sub 0}(1710), and f{sub 0}(1370), respectively. The scalar state f{sub 0}(1500) may be a good candidate for the ground scalar glueball. The agreement between the present findings and those given by other different approaches is satisfactory.
B Decays Involving Light Mesons
Eschrich, Ivo Gough; /UC, Irvine
2007-01-09
Recent BABAR results for decays of B-mesons to combinations of non-charm mesons are presented. This includes B decays to two vector mesons, B {yields} {eta}{prime}({pi}, K, {rho}) modes, and a comprehensive Dalitz Plot analysis of B {yields} KKK decays.
Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards
2003-07-22
We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.
Techniques in meson spectroscopy
Longacre, R.S.
1991-12-31
This report contains lectures on the following topics: the quark model and beyond using quantum chromodynamics; analysis of formation reactions; energy dependence of the partial wave amplitudes; where the data for the t-matrix analysis comes from; and coupled channel analysis of isoscalar mesons.
B meson decays into charmless pseudoscalar scalar mesons
Delepine, D.; Lucio M, J. L.; Ramirez, Carlos A.; Mendoza S, J. A.
2007-06-19
The nonleptonic weak decays of meson B into a scalar and pseudoscalar meson are studied. The scalar mesons under consideration are {sigma} (or f0(600)), f0(980), a0(980) and K{sub 0}{sup *}(1430). We calculate the Branching ratios in the Naive Factorization approximation. Scalars are assumed to be qq-bar bounded sates, but an estimation can be obtained in the case they are four bounded states.
Bianco, Stefano
2006-02-11
The scenario of heavy quark meson spectroscopy underwent recently a major revolution, after the observation of BABAR and CLEO, confirmed by BELLE, of DsJ L=1 excited states, and by further evidences by SELEX. These experimental results have cast doubts on the incarnations of the ideas of Heavy Quark Effective Theory in heavy quark spectroscopy. I shall review the status of experimental data, discuss implications and sketch an outlook.
Rare B Meson Decays With Omega Mesons
Zhang, Lei; /Colorado U.
2006-04-24
Rare charmless hadronic B decays are particularly interesting because of their importance in understanding the CP violation, which is essential to explain the matter-antimatter asymmetry in our universe, and of their roles in testing the ''effective'' theory of B physics. The study has been done with the BABAR experiment, which is mainly designed for the study of CP violation in the decays of neutral B mesons, and secondarily for rare processes that become accessible with the high luminosity of the PEP-II B Factory. In a sample of 89 million produced B{bar B} pairs on the BABAR experiment, we observed the decays B{sup 0} {yields} {omega}K{sup 0} and B{sup +} {yields} {omega}{rho}{sup +} for the first time, made more precise measurements for B{sup +} {yields} {omega}h{sup +} and reported tighter upper limits for B {yields} {omega}K* and B{sup 0} {yields} {omega}{rho}{sup 0}.
The light meson spectroscopy program
Smith, Elton S.
2014-06-01
Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.
Exotic meson spectroscopy with CLAS
Adams, G.; Napolitano, J.
1994-04-01
The identification and study of mesons with explicit gluonic degrees of freedom will provide major constraints on nonperturbative QCD and models thereof. CLAS will provide a unique opportunity for studying these resonances by measuring photoproduction of multi-meson final states.
Physics opportunities with meson beams
Briscoe, William J.; Doring, Michael; Haberzettl, Helmut; Manley, D. Mark; Naruki, Megumi; Strakovsky, Igor I.; Swanson, Eric S.
2015-10-20
Over the past two decades, meson photo- and electro-production data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledge in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state of-the-art meson-beam facility needs to be constructed. Furthermore, the present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.
Crowe, K.M.
1992-01-01
The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p[bar p] annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.
Crowe, K.M.
1992-12-01
The activities of this group are primarily concerned with experiments using the Crystal Barrel Detector. This detector is installed and operating at the Low Energy Antiproton Ring (LEAR) at CERN. QCD, the modem theory of the strong interaction, is reasonably well understood at high energies, but unfortunately, low-energy QCD is still not well understood, and is far from being adequately tested. The Crystal Barrel experiments are designed to provide some of the tests. The basic line of research involves meson spectroscopy, analyses bearing on the quark and/or gluon content of nuclear states, and the exploration of mechanisms and rules which govern p{bar p} annihilation dynamics. The Crystal Barrel Detector detects and identifies charged and neutral particles with a geometric acceptance close to 100%. The principal component of the detector is an array of 1,380 CsI(TI) crystals. These crystals surround a Jet Drift Chamber (JDC), located in a 1.5 Tesla magnetic field, which measures the momentum and dE/dx of charged particles. One of the very interesting physics goals of the detector is a search for exotic mesonic states -- glueballs and hybrids. Annihilation at rest will be studied with both liquid and gaseous hydrogen targets. The gaseous target offers the possibility of triggering on atomic L-shell X rays so that specific initial angular momentum states can be studied.These topics as well as other related topics are discussed in this report.
PSEUDOVECTOR MESONS, HYBRIDS AND GLUEBALLS
L. BURAKOVSKY; P. PAGE
2000-06-01
The authors consider glueball-(hybrid) meson mixing for the low-lying four pseudovector states. The h{sub 1}{prime}(1380) decays dominantly to K*K with some presence in {rho}{pi} and {omega}{eta}. The newly observed h{sub 1}(1600) has a D- to S-wave width ratio to {omega}{eta} which makes its interpretation as a conventional meson unlikely. They predict the decay pattern of the isopartner conventional or hybrid meson b{sub 1}(1650). A notably narrow s{bar s} partner h{sub 1}{prime}(1810) is predicted.
NASA Astrophysics Data System (ADS)
Battaglieri, Marco
The CLAS Collaboration is operating the CLAS detector at theThomas Jefferson National Laboratory (JLab) in USA. The unique combination of the detector large acceptance and high intensity of the continuous electron beam of CEBAF has opened the way to a comprehensive study of the hadrons structure in a kinematic domain between nuclear and particle physics. Meson spectroscopy plays a central role in the physics program of the Collaboration. Many exclusive channels have been studied with virtual and real photon beams in a wide kinematic domain providing key information about the hadron structure as well as the reactions dynamic. In this contribution, the rich physics program covered by present and future experiments will be reviewed.
NASA Astrophysics Data System (ADS)
Pennington, M. R.
1989-04-01
The search for I=0 0++ mesons is described. We highlight the crucial role played by the states in the 1 GeV region. An analysis program that with unimpeachable data would produce definitive results on these is outlined and shown with present data to provide prima facie evidence for dynamics beyond that of the quark model. We briefly speculate on the current status of the lowest mass scalar mesons and discuss how experiment can resolve the unanswered issues.
D meson decay channels that involve light scalar mesons
NASA Astrophysics Data System (ADS)
Fariborz, Amir
2013-04-01
A generalized linear sigma model of low-energy QCD is used to study several decay channels of D mesons that involve light scalar meson as a decay product. Such studies require reliable models for scalar mesons that take into account underlying mixing among quark-antiquarks, tetra quarks and glueballs. In this talk, the generalized linear sigma model of low-energy QCD for understanding the properties of scalar mosons will be briefly presented, and he application of this model to studies of heavier meson decays [such as the semileptonic decay Ds(1968)->f0(980) e^+ ν] will be presented, and a few directions for further extensions of the model will be outlined. Refs. A.H. Fariborz, R. Jora, J. Schechter and M.N. Shahid, ``Semi-leptonic Ds^+(1968) Decays as a Scalar Meson Probe,'' Physical Review D 84, 094024 (2011). A.H. Fariborz, R. Jora, J. Schechter and M.N. Shahid, ``Chiral Nonet Mixing in pi-pi Scattering,'' Physical Review D 84, 113004 (2011).
Schubert, K.R.
1988-11-20
The third generation of quarks, anticipated in 1973 by Kobayashi and Maskawa as one of the possibilities to explain CP violation of the K/sup o/-meson system within the framework of the Standard Model and in 1975 by the discovery of the third generation of leptons, was found at FNAL in 1977. It showed up in form of the UPSILON(1S) resonance, the lowest-energy 1/sup - -/ state of the b-quark- anti-b-antiquark system. Experiments at DESY in 1978 showed that the b-quark has charge 1/3. These and further experiments showed that the b- anti-b system follows the same spectroscopic and strong-interaction rules as the c- anti-c system. The physics of the b- anti-b system has been studied extensively at the DESY e/sup +/e/sup -/ storage ring DORIS using the detectors DASP-II, PLUTO, LENA, Crystal Ball, and ARGUS, and from 1980 on at the Cronell e/sup +/e/sup -/ ring CESR using CLEO and CUSB. Today we know twelve states of the b- anti-b system in contrast to seven of the c- anti-c system and only four in the e/sup +/e/sup -/ bound state system positronium. (AIP)
Physics opportunities with meson beams
Briscoe, William J.; Doring, Michael; Haberzettl, Helmut; Manley, D. Mark; Naruki, Megumi; Strakovsky, Igor I.; Swanson, Eric S.
2015-10-20
Over the past two decades, meson photo- and electro-production data of unprecedented quality and quantity have been measured at electromagnetic facilities worldwide. By contrast, the meson-beam data for the same hadronic final states are mostly outdated and largely of poor quality, or even nonexistent, and thus provide inadequate input to help interpret, analyze, and exploit the full potential of the new electromagnetic data. To reap the full benefit of the high-precision electromagnetic data, new high-statistics data from measurements with meson beams, with good angle and energy coverage for a wide range of reactions, are critically needed to advance our knowledgemore » in baryon and meson spectroscopy and other related areas of hadron physics. To address this situation, a state of-the-art meson-beam facility needs to be constructed. Furthermore, the present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.« less
Medium Modification of Vector Mesons
Chaden Djalali, Michael Paolone, Dennis Weygand, Michael H. Wood, Rakhsha Nasseripour
2011-03-01
The theory of the strong interaction, Quantum Chromodynamics (QCD), has been remarkably successful in describing high-energy and short-distance-scale experiments involving quarks and gluons. However, applying QCD to low energy and large-distance scale experiments has been a major challenge. Various QCD-inspired models predict a partial restoration of chiral symmetry in nuclear matter with modifications of the properties of hadrons from their free-space values. Measurable changes such as a shift in mass and/or a change of width are predicted at normal nuclear density. Photoproduction of vector mesons off nuclei have been performed at different laboratories. The properties of the ρ, ω and φ mesons are investigated either directly by measuring their mass spectra or indirectly through transparency ratios. The latest results regarding medium modifications of the vector mesons in the nuclear medium will be discussed.
Formation of Slow Heavy Mesons in Nuclei
NASA Astrophysics Data System (ADS)
Hirenzaki, Satoru
2009-10-01
Meson - nucleus systems such as mesic atoms and mesic nuclei have been studied systematically for a long time. The binding energies and widths of these bound states provide us unique and valuable information on the meson-nucleus interactions. In addition, the measurements of light vector meson spectra in nucleus as the invariant mass of lepton pairs have also provided interesting information. So far, the properties of relatively light mesons have been studied well both theoretically and experimentally. In this contribution, to extend our studies to a domain of heavier mesons, we would like to report recent research activities on the formation of heavy mesons in nuclei with small momenta. We think it is very interesting to consider the in-medium properties of heavier mesons including heavy quark contents. As a first step to heavier mesons, we will report our studies on formation of slow phi meson in nuclei. In-medium properties of phi meson have been studied theoretically, which have close relation to K and K-bar meson properties in medium because of the strong coupling of phi to K and K-bar. The study of QCD sum rule and the data taken at KEK suggested 3 percent mass reduction of phi at the normal nuclear density, while the phi meson selfenergy calculated in some effective models indicated a significantly smaller attractive potential for phi. We will show the calculated spectra for some reactions.
Volk, Alexei; /Dresden, Tech. U.
2010-08-26
The study of the semileptonic B-meson decays is the most accessible and cleanest way to determine the CKM matrix elements |V{sub cb}| and V{sub ub}. These decays also provide experimental access to study the QCD form-factors, heavy quark masses, and HQE parameters. The theoretical description of semileptonic B-meson decays at the parton level is very simple because there is no interaction between leptonic and hadronic currents. At the hadron level one needs to introduce corrections due to the strong interaction between quarks. Especially in the description of the inclusive B-meson decays the motion of the b-quark inside the B-meson plays a crucial role. All these effects are described in the frameworks of Heavy Quark Effective Theory (HQET) and Lattice QCD (LQCD). We give an overview about results of studies of semileptonic B-meson decays collected with the BABAR and Belle detectors at the PEP-II and the KEKB e{sup +}e{sup -}-storage rings. We present recent results on hadronic moments measured in inclusive B {yields} X{sub c}lv and B {yields} X{sub u}lv decays and extracted heavy quark masses m{sub b} and m{sub c} and dominant non-perturbative Heavy Quark Expansion (HQE) parameters. We also report the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| in inclusive and in exclusive semileptonic B-meson decays. We describe the studies of the form-factor parameters for the decay B{sup 0} {yields} D*{sup -}l{sup +}v and present the measurement of the B{sup 0} {yields} {pi}{sup -}l{sup +}v form-factor shape.
Meson spectroscopy with unitary coupled-channels model for heavy-meson decay into three mesons
Satoshi Nakamura
2012-04-01
We develop a model for describing excited mesons decay into three mesons. The properties of the excited mesons can be extracted with this model. The model maintains the three-body unitarity that has been missed in previous data analyses based on the conventional isobar models. We study an importance of the three-body unitarity in extracting hadron properties from data. For this purpose, we use the unitary and isobar models to analyze the same pseudo data of {gamma}p {yields} {pi}{sup +}{pi}{sup +}{pi}{sup -}n, and extract the properties of excited mesons. We find a significant difference between the unitary and isobar models in the extracted properties of excited mesons, such as the mass, width and coupling strength to decay channels. Hadron properties such as quantum numbers (spin, parity, etc.), mass and (partial) width have been long studied as a subject called hadron spectroscopy. The hadron properties provide important information for understanding internal structure of the hadron and dynamics which governs it. The dynamics here is of course QCD in its nonperturbative regime. The hadron properties can be extracted from data through a careful analysis, in many cases, partial wave analysis (PWA). Thus it is essential for hadron spectroscopy to have a reliable theoretical analysis tool.
Beauty meson decays to charmonium
NASA Astrophysics Data System (ADS)
Ershov, Alexey Valerievich
2001-10-01
We study decays of beauty (B) mesons into the final states containing charmonium mesons. The data were collected by the CLEO experiment at the Cornell Electron Storage Ring from 1990 to 1999. First, we describe a technique that significantly improves the reconstruction efficiency for decays of J/ y and y (2S) mesons into a pair of leptons. This reconstruction method is used in all the analyses presented in this dissertation. Then we present a study of B decays to the χc 1 and χc2 charmonium states and compare our results with the predictions of different theoretical models of charmonium production. After that we report the first observation of the decay B --> J/ y φK, which is the first B meson decay requiring a creation of an additional ss¯ quark pair. Then we measure the B0 and B+ meson masses from B0 --> y (') K0S and B+ --> y (') K+ decays. The method employed eliminates the dominant systematic uncertainty associated with the previous B meson mass measurements at the e+e- colliders and results in a significant improvement in precision. After that we present a study of three B0 decay modes useful for time-dependent CP asymmetry measurements. In this study we reconstruct B0 --> J/ y K0S , B0 --> χc 1 K0S , and B0 --> J/ y π0 decays. The latter two decay modes are observed for the first time. We describe a K0S --> π0π0 detection technique and its application to the reconstruction of the decay B 0 --> J/ y K0S . Then we present a sensitivity study for the measurement of the mixing-induced CP violation in the neutral B meson system (parameter sin 2β) at CLEO using the method that requires a measurement of the decay time of only one meson in a B0overline B0 pair. Finally, we search for direct CP violation in decays B+/- --> J/ y K+/- and B +/- --> y (2S) K+/- . The results of this search are consistent with the Standard Model expectations and provide the first experimental test of the assumption that direct CP violation is negligible in B --> y (') K decays.
Quantum Electrodynamics for Vector Mesons
Djukanovic, Dalibor; Schindler, Matthias R.; Scherer, Stefan; Gegelia, Jambul
2005-07-01
Quantum electrodynamics for {rho} mesons is considered. It is shown that, at the tree level, the value of the gyromagnetic ratio of the {rho}{sup +} is fixed to 2 in a self-consistent effective quantum field theory. Further, the mixing parameter of the photon and the neutral vector meson is equal to the ratio of electromagnetic and strong couplings, leading to the mass difference M{sub {rho}}{sub {sup 0}}-M{sub {rho}}{sub {sup {+-}}}{approx}1 MeV at tree order.
NASA Astrophysics Data System (ADS)
Albrecht, H.; Hamacher, T.; Hofmann, R. P.; Kirchhoff, T.; Mankel, R.; Nau, A.; Nowak, S.; Schröder, H.; Schulz, H. D.; Walter, M.; Wurth, R.; Hast, C.; Kapitza, H.; Kolanoski, H.; Kosche, A.; Lange, A.; Lindner, A.; Schieber, M.; Siegmund, T.; Spaan, B.; Thurn, H.; Töpfer, D.; Wegener, D.; Eckstein, P.; Schubert, K. R.; Schwierz, R.; Waldi, R.; Reim, K.; Wegener, H.; Eckmann, R.; Kuipers, H.; Mai, O.; Mundt, R.; Oest, T.; Reiner, R.; Schmidt-Parzefall, W.; Stiewe, J.; Werner, S.; Ehret, K.; Hofmann, W.; Hüpper, A.; Knöpfle, K. T.; Spengler, J.; Krieger, P.; Macfarlane, D. B.; Saull, P. R. B.; Tzamariudaki, K.; van de Water, R. G.; Yoon, T.-S.; Frankl, C.; Reßing, D.; Schmidtler, M.; Schneider, M.; Weseler, S.; Kernel, G.; Križan, P.; Križnič, E.; Podobnik, T.; Živko, T.; Balagura, V.; Belyaev, I.; Schechelnitsky, S.; Danilov, M.; Doutskoy, A.; Gershtein, Yu.; Golutvin, A.; Korolko, I.; Kostina, G.; Litvintsev, D.; Lubimov, V.; Pakhlov, P.; Semenov, S.; Snizhko, A.; Tichomirov, I.; Zaitsev, Yu.
1995-06-01
Using the ARGUS detector at the storage ring DORIS II we have measured τ decays into three charged mesons containing K * mesons. Exploiting the good particle identification capabilities of the detector we have determined the following branching ratios:Brleft( {tau ^ - to overline {K^{*0} } π ^ - v_tau } right) = left( {0.25 ± 0.10 ± 0.05} right)% , B r (τ-→ K *0 K - v τ)= (0.20±0.05±0.04)%, and B r (τ-→ K *- X 0 v τ) =(1.15±0.15-0.18 +0.13)%.
Theoretical overview: The New mesons
Quigg, Chris; /Fermilab
2004-11-01
After commenting on the state of contemporary hadronic physics and spectroscopy, I highlight four areas where the action is: searching for the relevant degrees of freedom, mesons with beauty and charm, chiral symmetry and the D{sub sJ} levels, and X(3872) and the lost tribes of charmonium.
Meson-baryon interaction in the meson exchange picture
Doering, M.
2011-10-24
Elastic {pi}N scattering and the reaction {pi}{sup +}p{yields}K{sup +}{Sigma}{sup +} are described simultaneously in a unitary coupled-channels approach which respects analyticity. SU(3) flavor symmetry is used to relate the t- and u- channel exchanges that drive the meson-baryon interaction in the different channels. Angular distributions, polarizations, and spin-rotation parameters are compared with available experimental data. The pole structure of the amplitudes is extracted from the analytic continuation.
Meson Photoproduction Experiments with CLAS
Eugene Pasyuk
2012-12-01
A large part of the experimental program in Hall B of the Jefferson Lab is dedicated to light baryon spectroscopy. Meson photoprodcution experiments are essential part of this program. CEBAF Large Acceptance Spectrometer (CLAS) and availability of circularly and linearly polarized tagged photon beams and frozen spin polarized targets provide unique conditions for this type of experiments. This combination of experimental tools gives a remarkable opportunity to measure double polarization observables for different pseudo-scalar meson photoproduction processes. For the first time, a complete or nearly complete measurement became possible and will facilitate model independent extraction of the reaction amplitude. An overview of the experimental program and its current status together with recent results on double polarization measurements in π{sup +} photoproduction are presented.
Lazzaro, Alfio; /Milan U. /INFN, Milan
2007-05-11
Symmetries and their conservation laws play a fundamental role in Physics. Among them, the discrete symmetries corresponding to charge (C), parity (P), and time (T) transformations are extensively used in the theory of the elementary particles and their interactions (so called Standard Model (SM)) to give the basis of the fundamental physical description of nature. Eventual discoveries of violations of these symmetries become a crucial test for our understanding of the nature. It was assumed that the three discrete symmetries were not violated until 1956 when it was found that P is violated in the weak interaction. Soon it was understood that also the C is violated in the weak interaction. At that time these two violated symmetries were replaced by their combination, CP, which was considered a new fundamental symmetry. In 1964 also the CP was found violated in the case of the neutral K meson system. Since that year there were many achievements in theories and experiments in order to explain this symmetry violation. In the last five years the main contribution comes from the discovery of the CP violation in B meson system. In this note we will describe briefly how the CP violation is described in the SM and the main experimental results obtained in the B mesons system.
Dynamical meson melting in holography
NASA Astrophysics Data System (ADS)
Ishii, Takaaki; Kinoshita, Shunichiro; Murata, Keiju; Tanahashi, Norihiro
2014-04-01
We discuss mesons in thermalizing gluon backgrounds in the = 2 super-symmetric QCD using the gravity dual. We numerically compute the dynamics of a probe D7-brane in the Vaidya-AdS geometry that corresponds to a D3-brane background thermalizing from zero to finite temperatures by energy injection. In static backgrounds, it has been known that there are two kinds of brane embeddings where the brane intersects the black hole or not. They correspond to the phases with melted or stable mesons. In our dynamical setup, we obtain three cases depending on final temperatures and injection time scales. The brane stays outside of the black hole horizon when the final temperature is low, while it intersects the horizon and settles down to the static equilibrium state when the final temperature is high. Between these two cases, we find the overeager case where the brane dynamically intersects the horizon although the final temperature is not high enough for a static brane to intersect the horizon. The interpretation of this phenomenon in the dual field theory is meson melting due to non-thermal effects caused by rapid energy injection. In addition, we comment on the late time evolution of the brane and a possibility of its reconnection.
Meson Spectroscopy at CLAS and CLAS12
Carlos Salgado
2011-10-01
We report on meson spectroscopy using the CLAS at Jefferson Lab. We study photo-production of exotic mesons and strangeonia on the largest data sample ever to be produced at photon energies of about 5 GeV. We also describe an experiment to continue meson spectroscopy at CLAS12 (CLAS energy upgrade) using electroproduction at very low Q2 ('quasireal photons') up to photon energies of 10 GeV.
Some recent results on meson spectroscopy
Chung, S.U.
1987-06-01
A comparative survey of established meson states with the predictions of a q anti q (quarkonium) model by Godfrey and Isgur shows that most meson states are well described, from pion to UPSILON(6S). However, a number of states in the light- quark isoscalar sector are not predicted at all in their model, pointing to a need for glueballs, hybrids and multi-quark states to fully account for recently reported meson states. 48 refs.
Indirect evidences for existence of exotic mesons in hadronic weak decays of K and charm mesons
Terasaki, K.
1998-05-29
It is demonstrated that hadronic weak decays of K and charm mesons are intimately related to hadron spectroscopy. Long standing puzzles in hadronic weak decays of charm mesons can be solved by taking account of dynamical contributions of various hadrons including non-qq-bar mesons.
Meson's correlation functions in a nuclear medium
NASA Astrophysics Data System (ADS)
Park, Chanyong
2016-09-01
We investigate meson's spectrum, decay constant and form factor in a nuclear medium through holographic two- and three-point correlation functions. To describe a nuclear medium composed of protons and neutrons, we consider a hard wall model on the thermal charged AdS geometry and show that due to the isospin interaction with a nuclear medium, there exist splittings of the meson's spectrum, decay constant and form factor relying on the isospin charge. In addition, we show that the ρ-meson's form factor describing an interaction with pseudoscalar fluctuation decreases when the nuclear density increases, while the interaction with a longitudinal part of an axial vector meson increases.
Vector meson masses in nuclear medium
NASA Astrophysics Data System (ADS)
Morones-Ibarra, Jose Ruben
1998-11-01
In this work I carry out theoretical calculations of the Rho meson mass in nuclear medium when it couples to two pions which strongly couple to in medium N/wedge/*N/wedge([-]1) states. The calculations are done from the modified Rho meson propagator in a non-relativistic approximation. Defining the Rho meson mass as the position of the peak of the spectral function, we find that there is an increase of the Rho meson mass as the density of the nuclear medium augments. The width of the spectral function becomes larger and the peak height is reduced with increasing nuclear densities.
The impact of vector mesons polarization on meson-nucleon interaction
NASA Astrophysics Data System (ADS)
Gevorkyan, Sergey
2016-02-01
Production of unstable particles off nuclei allows to determine the total cross section of the unstable particle interaction with nucleons. The interaction of vector mesons V(ρ, ω, ϕ) with nucleons are defined by a set of amplitudes corresponding to the transverse polarization of the vector meson (helicity λ = ±1) meson or longitudinal one (λ = 0). Whereas the total cross section for the interaction of the transversely polarized vector meson with nucleon σ T = σ(VTN) can be extract from the coherent photoproduction, measurements of vector meson interaction with nucleon σL= σ(VLN). As a good tool for such investigation we proposed the photoproduction of ω mesons on the set of nuclei in the incoherent region. Such experiment can be done using the feasibility of the new experiment GlueX at Jefferson Lab, designed to study the photoproduction of mesons in a large beam energy range up to 12 GeV.
NASA Astrophysics Data System (ADS)
Roe, Natalie A.
2001-04-01
Our world manifestly violates CP, the symmetry between matter and antimatter; there is no observational evidence for any significant amount of antimatter in the Universe. Andrei Sakharov was the first to point out that, in the context of Big Bang theory, a matter-dominated universe requires CP violation at the quantum level. Indeed, CP violation was subsequently observed as a tiny effect in K-meson decays, and it can be naturally accommodated in the Standard Model of fundamental particles with 3 generations of quarks. However, to produce the observed baryon asymmetry, baryogenesis calculations require more CP violation than the Standard Model affords. This is an intriguing puzzle whose solution will require input from both particle physics and cosmology, and it has inspired particle physicists to study CP violation with greater precision in a new generation of experiments. We are now entering this exciting new era in CP violation studies. Several new or upgraded experiments plan a program of detailed measurements of CP violating effects in B mesons. The predicted asymmetries are large, observable in a variety of decay channels, and the theoretical uncertainties are small for the best modes. Some interesting experimental results have recently been announced, and more precise measurements will soon follow. Future experiments are already planned to make even more definitive measurements. In this talk I will review the theoretical predictions and the connection to cosmology, survey the experimental scene, and describe how the study of CP violation in B mesons will allow us to make stringent tests of the Standard Model.
Meson-photon transition form factors
Balakireva, Irina; Lucha, Wolfgang; Melikhov, Dmitri
2012-10-23
We present the results of our recent analysis of the meson-photon transition form factors F{sub P{gamma}}(Q{sup 2}) for the pseudoscalar mesons P {pi}{sup 0},{eta},{eta} Prime ,{eta}{sub c}, using the local-duality version of QCD sum rules.
Heavy meson observables and Dyson Schwinger equations.
Ivanov, M. A.
1998-10-20
Dyson-Schwinger equation (DSE) studies show that the b-quark mass-function is approximately constant, and that this is true to a lesser extent for the c-quark. This observation provides the basis for a study of the leptonic and semileptonic decays of heavy pseudoscalar mesons using a ''heavy-quark'' limit of the DSES, which, when exact, reduces the number of independent form factors. Semileptonic decays with light mesons in the final state are also accessible because the DSES provide a description of light-quark propagation characteristics and light-meson structure. A description of B-meson decays is straightforward, however, the study of decays involving the D-meson indicates that c-quark mass-corrections are quantitatively important.
Excited light meson spectroscopy from lattice QCD
Christopher Thomas, Hadron Spectrum Collaboration
2012-04-01
I report on recent progress in calculating excited meson spectra using lattice QCD, emphasizing results and phenomenology. With novel techniques we can now extract extensive spectra of excited mesons with high statistical precision, including spin-four states and those with exotic quantum numbers. As well as isovector meson spectra, I will present new calculations of the spectrum of excited light isoscalar mesons, something that has up to now been a challenge for lattice QCD. I show determinations of the flavor content of these mesons, including the eta-eta' mixing angle, providing a window on annihilation dynamics in QCD. I will also discuss recent work on using lattice QCD to map out the energy-dependent phase shift in pi-pi scattering and future applications of the methodology to the study of resonances and decays.
Light Vector Mesons in the Nuclear Medium
Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis; Djalali, Chaden; Tur, Clarisse; Mosel, Ulrich; Muehlich, Pascal; Adams, Gary; Amaryan, Moscov; Amaryan, Moskov; Ambrozewicz, Pawel; Anghinolfi, Marco; Asryan, Gegham; Avagyan, Harutyun; Baghdasaryan, Hovhannes; Baillie, Nathan; Ball, James; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dashyan, Natalya; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dharmawardane, Kahanawita; Dickson, Richard; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fedotov, Gleb; Feldman, Gerald; Feuerbach, Robert; Fradi, Ahmed; Funsten, Herbert; Garcon, Michel; Gavalian, Gagik; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gordon, Christopher; Gothe, Ralf; Griffioen, Keith; Guidal, Michel; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hakobyan, Rafael; Hanretty, Charles; Hardie, John; Hassall, Neil; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Krahn, Zebulun; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Lachniet, Jeff; Laget, Jean; Langheinrich, Jorn; Lawrence, David; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Moriya, Kei; Morrow, Steven; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Pasyuk, Evgueni; Paterson, Craig; Pereira, Sergio; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Prok, Yelena; Protopopescu, Dan; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Ronchetti, Federico; Rosner, Guenther; Rossi, Patrizia; Sabatie, Franck; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Smith, Elton; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinsky, Aleksey; Stepanyan, Stepan; Stepanyan, Samuel; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro; Tedeschi, David; Tkabladze, Avtandil; Tkachenko, Svyatoslav; Todor, Luminita; Ungaro, Maurizio; Vineyard, Michael; Vlassov, Alexander; Watts, Daniel; Weinstein, Lawrence; Williams, Michael; Wolin, Elliott; Yegneswaran, Amrit; Zana, Lorenzo; Zhang, Bin; Zhang, Jixie; Zhao, Bo; Zhao, Zhiwen
2008-07-01
The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body eff
Semileptonic decays of B meson into charmed meson
Katayama, N. )
1989-12-15
Recent results on semileptonic decays of {ital B} meson into charmed meson using the CLEO detector at CESR are summarized. Ratios of the inclusive semileptonic branching fractions, B(B{sup {minus}}{r arrow}{ital D}{sup 0}{ital Xl}{sup {minus}}{bar {nu}}), B({ital {bar B}}{sup 0}{r arrow}{ital D}{sup +}{ital Xl}{sup {minus}}{bar {nu}}{ital Xl}{sup {minus}}{bar {nu}}), and B({ital {bar B}}{sup 0}{r arrow}{ital D}{sup +}) average {ital B} meson semileptonic branching fraction are reported. The branching fractions of the exclusive final states, {ital B}{sup {minus}}{r arrow}{ital D}{sup 0}{ital l}{sup {minus}}{bar {nu}}, {ital B}{sup {minus}}{r arrow}{ital D}{sup 0}{ital l}{sup {minus}}{bar {nu}}, and {ital {bar B}}{sup 0}{r arrow}{ital D}{sup +}{ital l}{sup {minus}}{bar {nu}} are measured. The ratio of B({ital B}{sup {minus}}{r arrow}{ital D}{sup 0}{ital l}{sup {minus}}{bar {nu}}) to B(B{sup {minus}}{r arrow}{ital D}{sup 0}{ital l}{sup {minus}}{bar {nu}}) and the polarization of the {ital D}*{sup +} are obtained and compared with theoretical models. The value of {vert bar}{ital V}{sub {ital c}{ital b}}{vert bar} is calculated from the exclusive branching fractions for various models. Finally, the lifetime ratio of the charged and neutral {ital B}'s ({tau}{sup +}/{tau}{sup 0}) is determined from the ratio of B({ital B}{sup {minus}}{r arrow}{ital D}{sup 0}{ital l}{sup {minus}}{bar {nu}}) to B({ital {bar B}}{sup 0}{r arrow}{ital D}{sup +}{ital l}{sup {minus}}{bar {nu}}) to be 0.85{plus minus}0.20{sup +0.22}{sub {minus}0.16}.
Photoproduction of the rho meson and its magnetic moments
Kaneko, Hiromi; Hosaka, Atsushi; Scholten, Olaf
2011-10-21
We study photoproduction of {rho} meson in a model of hidden local symmetry. We introduce the {rho} meson on a hidden gauge boson and phenomenological {rho} meson-nucleon Lagrangian is constructed respecting chiral symmetry. It turns out that the {sigma}-exchange interaction plays an important role in neutral {rho} meson photoproduction to reproduce the experimental cross sections. In charged {rho} meson photoproduction, the model takes into account the {rho} meson magnetic moments from the three-point vertex in the kinetic terms. We show that the magnetic moment of the charged {rho} meson has a significant effect on the total cross sections in proportion to the photon energies.
GlueX: Meson Spectroscopy in Photoproduction
Salgado, Carlos; Smith, Elton S.
2014-03-01
The goal of the GlueX experiment \\cite{gluex} is to provide crucial data to help understand the soft gluonic fields responsible for binding quarks in hadrons. Hybrid mesons, and in particular exotic hybrid mesons, provide the ideal laboratory for testing QCD in the confinement regime since these mesons explicitly manifest the gluonic degrees of freedom. Photoproduction is expected to be effective in producing exotic hybrids but there is little data on the photoproduction of light mesons. GlueX will use the new 12-GeV electron beam at Jefferson Lab to produce a 9-GeV beam of linearly polarized photons using the technique of coherent bremsstrahlung. A solenoid-based hermetic detector is under construction, which will be used to collect data on meson production and decays. These data will also be used to study the spectrum of conventional mesons, including the poorly understood excited vector mesons. This talk will give an update on the experiment as well as describe theoretical developments \\cite{Dudek:2011bn} to help understand how these data can provide insights into the fundamental theory of strong interactions.
Photoproduction of ω mesons off nuclei and impact of polarization on the meson-nucleon interaction
NASA Astrophysics Data System (ADS)
Chudakov, E.; Gevorkyan, S.; Somov, A.
2016-01-01
We use photoproduction of ω mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized vector mesons with nucleons σT=σ (VTN ) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the yet unmeasured total cross section for longitudinally polarized mesons σL=σ (VLN ) . The predictions for the latter strongly depend on the theoretical approaches. This work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designed to study the photoproduction of mesons in the beam energy range between 5 and 12 GeV.
Photoproduction of ω mesons off nuclei and impact of polarization on the meson-nucleon interaction
Chudakov, Eugene A.; Gevorkyan, Sergey; Somov, Alexander
2016-01-25
We consider photoproduction of ω mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized vector mesons with nucleons σT = σ(VTN) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the not-yet-measured total cross section for longitudinally polarized mesons σL = σ(VLN). The predictions for the latter strongly depend on the theoretical approaches. Furthermore, this work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designedmore » to study the photoproduction of mesons in a large beam energy range up to 12 GeV.« less
Mesons and flavor on the conifold
Levi, Thomas S.; Ouyang, Peter
2007-11-15
We explore the addition of fundamental matter to the Klebanov-Witten field theory. We add probe D7-branes to the N=1 theory obtained from placing D3-branes at the tip of the conifold and compute the meson spectrum for the scalar mesons. In the UV limit of massless quarks we find the exact dimensions of the associated operators, which exhibit a simple scaling in the large-charge limit. For the case of massive quarks we compute the spectrum of scalar mesons numerically.
From the {psi} to charmed mesons
Goldhaber, G. |
1994-11-01
This talk deals with the author`s recollections about the discoveries of the J/{psi} the {psi}{prime} as well as psion spectroscopy and charmed mesons. He gives a chronology for the {psi} and {psi}{prime} discoveries. He also discusses the events which led to the charmed meson discovery as well as detailed discussions on the proof that the resonance observed in the K{sup {minus}} {pi}{sup +} system, at 1,865 MeV, was indeed the predicted charmed meson.
Charge asymmetry in charmed-meson photoproduction
Berezhnoy, A. V. Likhoded, A. K.
2006-01-15
Within the perturbative-recombination model, the charge asymmetries in the D*{sup +}-D*{sup -}, D*{sup 0}-D*{sup 0}, and D{sup +}{sub s}-D{sup -}{sub s} yields are estimated under the kinematical conditions of the COMPASS experiment. Corrections that arise owing to the mass of a light quark in a charmed meson are taken into account. The yield of D{sup +}{sub s} mesons is predicted to be large in relation to the yield of D{sup -}{sub s} mesons.
Hard Exclusive Vector Meson Leptoproduction At HERMES
Golembiovskaya, M.
2011-07-15
The HERMES experiment at DESY, Hamburg collected a set of data on hard exclusive vector meson ({rho}{sup 0}{phi},{omega}) leptoproduction using the 27.6 GeV longitudinally polarized lepton beam of HERA accelerator and longitudinally or transversely polarized or unpolarized gas targets. Measurements of exclusive vector meson production provide access to the structure of the nucleon since the process can be described in terms of Generalized Parton Distributions (GPDs). An overview of the HERMES results on exclusive vector mesons production is presented.
Baby Skyrmions stabilized by vector mesons
Foster, David; Sutcliffe, Paul
2009-06-15
Recent results suggest that multi-Skyrmions stabilized by {omega} mesons have very similar properties to those stabilized by the Skyrme term. In this paper we present the results of a detailed numerical investigation of a (2+1)-dimensional analogue of this situation. Namely, we compute solitons in an O(3) {sigma} model coupled to a massive vector meson and compare the results to baby Skyrmions, which are solitons in an O(3) {sigma} model including a Skyrme term. We find that multisolitons in the vector meson model are surprisingly similar to those in the baby Skyrme model, and we explain this correspondence using a simple derivative expansion.
Tetraquarks in the 1 /N expansion and meson-meson resonances
NASA Astrophysics Data System (ADS)
Maiani, L.; Polosa, A. D.; Riquer, V.
2016-06-01
Diquarks are found to have the right degrees of freedom to describe the tetraquark poles in hidden-charm to open-charm meson-meson amplitudes. Compact tetraquarks result as intermediate states in non-planar diagrams of the 1 /N expansion and the corresponding resonances are narrower than what estimated before. The proximity of tetraquarks to meson-thresholds has an apparent role in this analysis and, in the language of meson molecules, an halving rule in the counting of states is obtained.
NASA Astrophysics Data System (ADS)
Gubler, Philipp; Hattori, Koichi; Lee, Su Houng; Oka, Makoto; Ozaki, Sho; Suzuki, Kei
2016-03-01
We investigate the mass spectra of open heavy flavor mesons in an external constant magnetic field within QCD sum rules. Spectral Ansätze on the phenomenological side are proposed in order to properly take into account mixing effects between the pseudoscalar and vector channels, and the Landau levels of charged mesons. The operator product expansion is implemented up to dimension-5 operators. As a result, we find for neutral D mesons a significant positive mass shift that goes beyond simple mixing effects. In contrast, charged D mesons are further subject to Landau level effects, which together with the mixing effects almost completely saturate the mass shifts obtained in our sum rule analysis.
Recent progress on light scalar mesons
Peláez, J. R.
2014-07-23
This is a brief account of the recent developments on the determination of the mass and widths of the much debated scalar mesons, paying particular attention to the causes of major revision of the σ or f{sub 0}(500) meson in the last edition of the Review of Particle Physics, which has finally acknowledged that the situation concerning the mass and width of this controversial state has been settled, although this was already well-known to scalar meson practitioners for about a decade. I will briefly comment on the dispersive approach, followed by several groups, which seems to have been the most decisive in support of the existence and precise determinations of scalar meson properties.
Meson wave function from holographic approaches
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2010-08-04
We discuss the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence. We consider two kinds of wave functions obtained in different holographic Soft-Wall approaches.
Gubler, Philipp; Hattori, Koichi; Lee, Su Houng; Oka, Makoto; Ozaki, Sho; Suzuki, Kei
2016-03-15
In this paper, we investigate the mass spectra of open heavy flavor mesons in an external constant magnetic field within QCD sum rules. Spectral Ansatze on the phenomenological side are proposed in order to properly take into account mixing effects between the pseudoscalar and vector channels, and the Landau levels of charged mesons. The operator product expansion is implemented up to dimension-5 operators. As a result, we find for neutral D mesons a significant positive mass shift that goes beyond simple mixing effects. In contrast, charged D mesons are further subject to Landau level effects, which together with the mixingmore » effects almost completely saturate the mass shifts obtained in our sum rule analysis.« less
Rare meson decays into very light neutralinos
O'Leary, Ben
2010-02-10
Results are presented for the two-body decays of mesons into light neutralinos and from the first complete calculation of the loop-induced decays of kaons to pions plus light neutralinos and of B mesons to kaons plus light neutralinos. The branching ratios are shown to be strongly suppressed within the MSSM with minimal flavor violation, and no bounds on the neutralino mass can be inferred from experimental data, i.e. a massless neutralino is allowed.
Strangeness in the Meson Cloud Model
Signal, A. I.
2010-07-27
I review progress in calculating strange quark and antiquark distributions of the nucleon using the meson cloud model. This progress parallels that of the meson cloud model, which is now a useful theoretical basis for understanding symmetry breaking in nucleon parton distribution functions. I examine the breaking of symmetries involving strange quarks and antiquarks, including quark--antiquark symmetry in the sea, SU(3) flavour symmetry and SU(6) spin-flavour symmetry.
Meson and Baryon Spectroscopy on the Lattice
Richards, D. G.
2010-12-28
Recent progress at understanding the excited state spectrum of mesons and baryons is described. I begin by outlining the application of the variational method to compute the spectrum, and the program of anisotropic clover lattice generation designed for hadron spectroscopy. I present results for the excited meson spectrum, with continuum quantum numbers of the states clearly delineated. I conclude with recent results for the low lying baryon spectrum, and the prospects for future calculations.
Meson and baryon spectroscopy on the lattice
David Richards
2010-12-01
Recent progress at understanding the excited state spectrum of mesons and baryons is described. I begin by outlining the application of the variational method to compute the spectrum, and the program of anisotropic clover lattice generation designed for hadron spectroscopy. I present results for the excited meson spectrum, with continuum quantum numbers of the states clearly delineated. I conclude with recent results for the low lying baryon spectrum, and the prospects for future calculations.
Exotic Meson Results from BNL E852
NASA Astrophysics Data System (ADS)
Manak, Joseph J.
1998-10-01
Results from BNL experiment 852 on exotic (non-q\\overlineq) meson production are presented. Production of final states with J^PC = 1^-+ is observed in π^-p interactions at 18 GeV/c in the ηπ^-, ρπ^- and η^'π^- channels. Since such states are manifestly exotic if they are resonant, we describe amplitude analyses which use the interference between these states and other well known states to measure the phase behavior of the J^PC = 1^-+ amplitudes. The analyses show that, in addition to the previously reported(D.R. Thompson et al.), Phys. Rev. Lett. 79, 1630 (1997) evidence for an exotic meson in the ηπ^- channel, there is strong evidence for a second exotic meson decaying to ρπ^- with a mass of M=1593 ±8^+29_-47 MeV/c^2 and a width of Γ=168 ±20^+150_-12 MeV/c^2. We also show that the η^'π^- system is dominated by J^PC = 1^-+ production and we use those data to determine decay branching ratios for the exotic mesons. Such measurements are expected to be crucial in determining the constituent nature of the exotic mesons - that is, whether they are consistent with being hybrid mesons or four-quark states.
Branching ratios of B{sub c} meson decays into tensor meson in the final state
Sharma, Neelesh
2010-01-01
Two-body hadronic weak decays of B{sub c} meson involving tensor meson in the final state are studied by using the Isgur-Scora-Grinstein-Wise II model. Decay amplitudes are obtained using the factorization scheme in the spectator quark model. Branching ratios for the charm changing and bottom changing decay modes are predicted.
Photoproduction and Decay of Light Mesons in CLAS
Amaryan, Moskov Jamalovich
2013-08-01
We present preliminary experimental results on photoproduction and decay of light mesons measured with CLAS setup at JLAB . This include Dalitz decay of pseudoscalar and vector mesons, radiative decay of pseudoscalar mesons as well hadronic decays of pseudoscalar and vector mesons. The collected high statistics in some of decay channels exceeds the world data by an order of magnitude and some other decay modes are observed for the first time. It is shown how the CLAS data will improve the world data on transition form factors of light mesons, Dalitz plot analyses, branching ratios of rare decay modes and other fundamental properties potentially accessible through the light meson decays.
Meson Spectroscopy in the Light Quark Sector
de Vita, Raffaella
2014-04-01
Understanding the hadron spectrum is one of the fundamental issues in modern particle physics. We know that existing hadron configurations include baryons, made of three quarks, and mesons, made of quark-antiquark pairs. However most of the mass of the hadrons is not due to the mass of these elementary constituents but to their binding force. Studying the hadron spectrum is therefore a tool to understand one of the fundamental forces in nature, the strong force, and Quantum Chromo Dynamics (QCD), the theory that describes it. This investigation can provide an answer to fundamental questions as what is the origin of the mass of hadrons, what is the origin of quark confinement, what are the relevant degrees of freedom to describe these complex systems and how the transition between the elementary constituents, quarks and gluons, and baryons and mesons occurs. In this field a key tool is given by meson spectroscopy. Mesons, being made by a quark and an anti-quark, are the simplest quark bound system and therefore the ideal benchmark to study the interaction between quarks and understand what the role of gluons is. In this investigation, it is fundamental to precisely determine the spectrum and properties of mesons but also to search for possible unconventional states beyond the configuration q{anti q} as tetraquarks (qq{anti qq}), hybrids (q{anti q}g) and glueballs. These states can be distinguished unambiguously from regular mesons when they have exotic quantum numbers, i.e. combinations of total angular momentum, spin and parity that are not allowed for q{anti q} states. These are called exotic quantum numbers and the corresponding states are referred to as exotics. The study of the meson spectrum and the search for exotics is among the goals of several experiments in the world that exploit different reaction processes, as e{sup +}e{sup −} annihilation, p{anti p} annihilation, pion scattering, proton-proton scattering and photo-production, to produce meson states
Scalar meson spectroscopy with lattice staggered fermions
Bernard, Claude; DeTar, Carleton; Fu Ziwen; Prelovsek, Sasa
2007-11-01
With sufficiently light up and down quarks the isovector (a{sub 0}) and isosinglet (f{sub 0}) scalar meson propagators are dominated at large distance by two-meson states. In the staggered-fermion formulation of lattice quantum chromodynamics, taste-symmetry breaking causes a proliferation of two-meson states that further complicates the analysis of these channels. Many of them are unphysical artifacts of the lattice approximation. They are expected to disappear in the continuum limit. The staggered-fermion fourth-root procedure has its purported counterpart in rooted staggered chiral perturbation theory (rS{chi}PT). Fortunately, the rooted theory provides a strict framework that permits the analysis of scalar meson correlators in terms of only a small number of low-energy couplings. Thus the analysis of the point-to-point scalar meson correlators in this context gives a useful consistency check of the fourth-root procedure and its proposed chiral realization. Through numerical simulation we have measured correlators for both the a{sub 0} and f{sub 0} channels in the 'Asqtad' improved staggered-fermion formulation in a lattice ensemble with lattice spacing a=0.12 fm. We analyze those correlators in the context of rS{chi}PT and obtain values of the low-energy chiral couplings that are reasonably consistent with previous determinations.
B meson decays to charmless meson pairs containing η or η' mesons
NASA Astrophysics Data System (ADS)
Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; 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.; Tackmann, K.; Tanabe, T.; Hawkes, C. M.; Soni, N.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Fulsom, B. G.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Barrett, M.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Bukin, A. D.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Bondioli, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Yasin, Z.; Sharma, V.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Mazur, M. A.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Wang, L.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Fang, F.; Hitlin, D. G.; Narsky, I.; Ongmongkolkul, P.; Piatenko, T.; Porter, F. C.; Andreassen, R.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Hirschauer, J. F.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Wilson, R. J.; Feltresi, E.; Hauke, A.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Nogowski, R.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Latour, E.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Chaisanguanthum, K. S.; Morii, M.; Adametz, A.; Marks, J.; Schenk, S.; Uwer, U.; Bernlochner, F. U.; Klose, V.; Lacker, H. M.; Lueck, T.; Volk, A.; Bard, D. J.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Charles, M. J.; Mallik, U.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Béquilleux, J.; D'Orazio, A.; Davier, M.; Derkach, D.; da Costa, J. Firmino; Grosdidier, G.; Le Diberder, F.; Lepeltier, V.; Lutz, A. M.; Malaescu, B.; Pruvot, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Clarke, C. K.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; West, T. J.; Yi, J. I.; Anderson, J.; Chen, C.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Henderson, S. W.; Sciolla, G.; Spitznagel, M.; Yamamoto, R. K.; Zhao, M.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Zhao, H. W.; Simard, M.; Taras, P.; Nicholson, H.; de Nardo, G.; Lista, L.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Sekula, S. J.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Lu, M.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Del Amo Sanchez, P.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Perez, A.; Prendki, J.; Sitt, S.; Gladney, L.; Biasini, M.; Manoni, E.; Angelini, C.; Batignani, G.; Bettarini, S.; Calderini, G.; Carpinelli, M.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Li Gioi, L.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Renga, F.; Voena, C.; Ebert, M.; Hartmann, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Esteve, L.; Hamel de Monchenault, G.; Kozanecki, W.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bartoldus, R.; Benitez, J. F.; Cenci, R.; Coleman, J. P.; Convery, M. R.; Dingfelder, J. C.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Marsiske, H.; Messner, R.; Muller, D. R.; Neal, H.; Nelson, S.; O'Grady, C. P.; Ofte, I.; Perl, M.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Thompson, J. M.; Va'Vra, J.; Wagner, A. P.; Weaver, M.; West, C. A.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Bellis, M.; Burchat, P. R.; Edwards, A. J.; Miyashita, T. S.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Pan, B.; Saeed, M. A.; Zain, S. B.; Soffer, A.; Spanier, S. M.; Wogsland, B. J.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Drummond, B. W.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Bosisio, L.; Cartaro, C.; Della Ricca, G.; Lanceri, L.; Vitale, L.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Albert, J.; Banerjee, Sw.; Bhuyan, B.; Choi, H. H. F.; Hamano, K.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Gershon, T. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Puccio, E. M. T.; Band, H. R.; Chen, X.; Dasu, S.; Flood, K. T.; Pan, Y.; Prepost, R.; Vuosalo, C. O.; Wu, S. L.
2009-12-01
We present updated measurements of the branching fractions for B0 meson decays to ηK0, ηη, ηϕ, ηω, η'K0, η'η', η'ϕ, and η'ω, and branching fractions and CP-violating charge asymmetries for B+ decays to ηπ+, ηK+, η'π+, and η'K+. The data represent the full data set of 467×106 BB¯ pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. Besides large signals for the four charged B decay modes and for B0→η'K0, we find evidence for three B0 decay modes at greater than 3.0σ significance. We find B(B0→ηK0)=(1.15-0.38+0.43±0.09)×10-6, B(B0→ηω)=(0.94-0.30+0.35±0.09)×10-6, and B(B0→η'ω)=(1.01-0.38+0.46±0.09)×10-6, where the first (second) uncertainty is statistical (systematic). For the B+→ηK+ decay mode, we measure the charge asymmetry Ach(B+→ηK+)=-0.36±0.11±0.03.
Review of meson spectroscopy: quark states and glueballs
Chanowitz, M.S.
1981-11-01
A group of three lectures on hadron spectroscopy are presented. Topics covered include: light L = 0 mesons, light L = 1 mesons, antiquark antiquark quark quark exotics, a catalogue of higher quark antiquark excitations, heavy quarkonium, and glueballs. (GHT)
Vector meson modification in nuclear matter at CLAS
Djalali, Chaden; Wood, Michael; Nasseripour, Rakhsha; Weygand, Dennis
2008-09-01
Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The properties of the A vector mesons were investigated via their rare leptonic decay to e+e . After subtracting the combinatorial background, the A meson mass distributions were extracted for each of the targets. We observe no effects on the mass of the A meson, some widening in titanium and iron is observed consistent with the collisional broadening.
Unitary coupled-channels model for three-mesons decays of heavy mesons
Hiroyuki Kamano; Nakamura, Satoshi X.; Lee, Tsung-Shung H.; Sato, Toru
2011-12-16
In this study, a unitary coupled-channels model is presented for investigating the decays of heavy mesons and excited meson states into three light pseudoscalar mesons. The model accounts for the three-mesons final state interactions in the decay processes, as required by both the three-body and two-body unitarity conditions. In the absence of the Z-diagram mechanisms that are necessary consequences of the three-body unitarity, our decay amplitudes are reduced to a form similar to those used in the so-called isobar-model analysis. We apply our coupled-channels model to the three-pions decays of α_{1}(1260), π_{2}(1670), π_{2}(2100), and D^{0} mesons, and show that the Z-diagram mechanisms can contribute to the calculated Dalitz plot distributions by as much as 30% in magnitudes in the regions where f_{0}(600), ρ(770), and f_{2}(1270) dominate the distributions. Also, by fitting to the same Dalitz plot distributions, we demonstrate that the decay amplitudes obtained with the unitary model and the isobar model can be rather different, particularly in the phase that plays a crucial role in extracting the CKM CP-violating phase from the data of B meson decays. Our results indicate that the commonly used isobar model analysis must be extended to account for the final state interactions required by the three-body unitarity to reanalyze the three-mesons decays of heavy mesons, thereby exploring hybrid or exotic mesons, and signatures of physics beyond the standard model.
Unitary coupled-channels model for three-mesons decays of heavy mesons
Hiroyuki Kamano; Nakamura, Satoshi X.; Lee, Tsung-Shung H.; Sato, Toru
2011-12-16
In this study, a unitary coupled-channels model is presented for investigating the decays of heavy mesons and excited meson states into three light pseudoscalar mesons. The model accounts for the three-mesons final state interactions in the decay processes, as required by both the three-body and two-body unitarity conditions. In the absence of the Z-diagram mechanisms that are necessary consequences of the three-body unitarity, our decay amplitudes are reduced to a form similar to those used in the so-called isobar-model analysis. We apply our coupled-channels model to the three-pions decays of α1(1260), π2(1670), π2(2100), and D0 mesons, and show that themore » Z-diagram mechanisms can contribute to the calculated Dalitz plot distributions by as much as 30% in magnitudes in the regions where f0(600), ρ(770), and f2(1270) dominate the distributions. Also, by fitting to the same Dalitz plot distributions, we demonstrate that the decay amplitudes obtained with the unitary model and the isobar model can be rather different, particularly in the phase that plays a crucial role in extracting the CKM CP-violating phase from the data of B meson decays. Our results indicate that the commonly used isobar model analysis must be extended to account for the final state interactions required by the three-body unitarity to reanalyze the three-mesons decays of heavy mesons, thereby exploring hybrid or exotic mesons, and signatures of physics beyond the standard model.« less
Magnetic properties of ground-state mesons
NASA Astrophysics Data System (ADS)
Šimonis, V.
2016-04-01
Starting with the bag model a method for the study of the magnetic properties (magnetic moments, magnetic dipole transition widths) of ground-state mesons is developed. We calculate the M1 transition moments and use them subsequently to estimate the corresponding decay widths. These are compared with experimental data, where available, and with the results obtained in other approaches. Finally, we give the predictions for the static magnetic moments of all ground-state vector mesons including those containing heavy quarks. We have a good agreement with experimental data for the M1 decay rates of light as well as heavy mesons. Therefore, we expect our predictions for the static magnetic properties ( i.e., usual magnetic moments) to be of sufficiently high quality, too.
Lepton flavor violating decays of vector mesons
Gutsche, Thomas; Lyubovitskij, Valery E.; Helo, Juan C.; Kovalenko, Sergey
2010-02-01
We estimate the rates of lepton flavor violating decays of the vector mesons {rho}, {omega}, and {phi}{yields}e{mu}. The theoretical tools are based on an effective Lagrangian approach without referring to any specific realization of the physics beyond the standard model responsible for lepton flavor violation (Le{sub f}). The effective lepton-vector meson couplings are extracted from the existing experimental bounds on the nuclear {mu}{sup -}-e{sup -} conversion. In particular, we derive an upper limit for the Le{sub f} branching ratio Br({phi}{yields}e{mu}){<=}1.3x10{sup -21} which is much more stringent than the recent experimental result Br({phi}{yields}e{mu})<2x10{sup -6} presented by the SND Collaboration. Very tiny limits on Le{sub f} decays of vector mesons derived in this paper make direct experimental observation of these processes unrealistic.
Exclusive vector meson production at HERMES
NASA Astrophysics Data System (ADS)
Movsisyan, Aram
2014-06-01
Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, more information can be obtained about generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of rho, omega and phi mesons will be presented.
Massive mesons in Weyl-Dirac theory
NASA Astrophysics Data System (ADS)
Mirabotalebi, S.; Ahmadi, F.; Salehi, H.
2008-01-01
In order to study the mass generation of the vector fields in the framework of a conformal invariant gravitational model, the Weyl-Dirac theory is considered. The mass of the Weyl’s meson fields plays a principal role in this theory, it connects basically the conformal and gauge symmetries. We estimate this mass by using the large-scale characteristics of the observed universe. To do this we firstly specify a preferred conformal frame as a cosmological frame, then in this frame, we introduce an exact possible solution of the theory. We also study the dynamical effect of the massive vector meson fields on the trajectories of an elementary particle. We show that a local change of the cosmological frame leads to a Hamilton-Jacobi equation describing a particle with an adjustable mass. The dynamical effect of the massive vector meson field presents itself in the form of a correction term for the mass of the particle.
Photoproduction of scalar mesons at medium energies
Da Silva, M. L.; Machado, M. V.
2013-03-25
In this work we will focus on photoproduction of mesons states a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710). The f{sub 0}(1500) and f{sub 0}(1710) mesons will be considered in distinct mixing possibilities and assuming that a{sub 0}(980) is member of the ground-state nonet. The theoretical formalism is the Regge approach with reggeized {rho} and {omega} exchange. The differential and integrated total cross section are computed for the cases of the mesons a{sub 0}(980), f{sub 0}(1500) and f{sub 0}(1710) focusing the GlueX energy regime with photon energy E = 9 GeV.
Scalar mesons in a linear sigma model with (axial-)vector mesons
Parganlija, D.; Kovacs, P.; Wolf, Gy.; Giacosa, F.; Rischke, D. H.
2013-03-25
The structure of the scalar mesons has been a subject of debate for many decades. In this work we look for qq states among the physical resonances using an extended Linear Sigma Model that contains scalar, pseudoscalar, vector, and axial-vector mesons both in the non-strange and strange sectors. We perform global fits of meson masses, decay widths and amplitudes in order to ascertain whether the scalar qq states are below or above 1 GeV. We find the scalar states above 1 GeV to be preferred as qq states.
Light O++ Mesons: Scalargators in Florida
NASA Astrophysics Data System (ADS)
Pennington, M. R.
2010-08-01
Light scalar mesons abound in hadron processes, like the alligators in the Florida Everglades. Moreover, scalars are intimately tied to the vacuum structure of QCD. They are the product of many decays. Consequently, a rich source of recent information about them has come from experiments producing heavy flavour mesons. Indeed, scalars will continue to dominate many of the processes to be studied at forthcoming facilities like BESIII in Beijing, FAIR at GSI Darmstadt and the GlueX experiment at JLab, making an understanding (or at least an excellent and theoretically consistent description) essential for the physics missions of these facilities.
CP violation in B meson decays
NASA Astrophysics Data System (ADS)
Noguchi, S.; Belle Group
2003-06-01
CP violation in neutral B meson decays has been observed confirming the prediction of the Kobayashi-Maskawa model where introduction of six quaks naturally induces CP violation in the weak interaction. The measurements of CP asymmetryc in B meson decays were made at the newly constructed Asymmetric B factories, which consist of high luminosity, ebergy-asymmetric e+e- colliders (KEKB and PEP-II) and detectors (Belle and BaBar). The results are in good agreement and are consistent with other experimental results within the framework of the Standard Model.
Exotic nuclei with open heavy flavor mesons
Yasui, Shigehiro; Sudoh, Kazutaka
2009-08-01
We propose stable exotic nuclei bound with D and B mesons with respect to heavy quark symmetry. We indicate that an approximate degeneracy of D(B) and D*(B*) mesons plays an important role, and discuss the stability of DN and BN bound states. We find the binding energies 1.4 MeV and 9.4 MeV for each state in the J{sup P}=1/2{sup -} with the I=0 channel. We discuss also possible existence of exotic nuclei DNN and BNN.
Excited light isoscalar mesons from lattice QCD
Christopher Thomas
2011-07-01
I report a recent lattice QCD calculation of an excited spectrum of light isoscalar mesons, something that has up to now proved challenging for lattice QCD. With novel techniques we extract an extensive spectrum with high statistical precision, including spin-four states and, for the first time, light isoscalars with exotic quantum numbers. In addition, the hidden flavour content of these mesons is determined, providing a window on annihilation dynamics in QCD. I comment on future prospects including applications to the study of resonances.
Meson spectrum in strong magnetic fields
NASA Astrophysics Data System (ADS)
Andreichikov, M. A.; Kerbikov, B. O.; Orlovsky, V. D.; Simonov, Yu. A.
2013-05-01
We study the relativistic quark-antiquark system embedded in a magnetic field (MF). The Hamiltonian containing confinement, one gluon exchange, and spin-spin interaction is derived. We analytically follow the evolution of the lowest meson states as a function of MF strength. Calculating the one gluon exchange interaction energy ⟨VOGE⟩ and spin-spin contribution ⟨aSS⟩ we have observed that these corrections remain finite at large MF, preventing the vanishing of the total ρ meson mass at some Bcrit, as previously thought. We display the ρ masses as functions of the MF in comparison with recent lattice data.
Scalar mesons and polarizability of the nucleon
Schumacher, Martin
2008-08-31
It is shown that the scalar mesons {sigma}, f{sub 0}(980) and a{sub 0}(980) as t-channel exchanges quantitatively solve the problem of diamagnetism and give an explanation of the large missing part of the electric polarizability {alpha} showing up when only the pion cloud is taken into account. The electric polarizability of the proton {alpha}{sub p} confirms a two-photon width of the {sigma} meson of {gamma}{sub {sigma}}{sub {gamma}}{sub {gamma}} = (2.58{+-}0.26) keV.
Tensor mesons produced in tau lepton decays
Lopez Castro, G.; Munoz, J. H.
2011-05-01
Light tensor mesons (T=a{sub 2}, f{sub 2} and K{sub 2}*) can be produced in decays of {tau} leptons. In this paper we compute the branching ratios of {tau}{yields}T{pi}{nu} decays by assuming the dominance of intermediate virtual states to model the form factors involved in the relevant hadronic matrix elements. The exclusive f{sub 2}(1270){pi}{sup -} decay mode turns out to have the largest branching ratio, of O(10{sup -4}). Our results indicate that the contribution of tensor meson intermediate states to the three-pseudoscalar channels of {tau} decays are rather small.
Shape of mesons in holographic QCD
Torabian, Mahdi; Yee, Ho-Ung
2009-10-15
Based on the expectation that the constituent quark model may capture the right physics in the large N limit, we point out that the orbital angular momentum of the quark-antiquark pair inside light mesons of low spins in the constituent quark model may provide a clue for the holographic dual string model of large N QCD. Our discussion, relying on a few suggestive assumptions, leads to a necessity of world-sheet fermions in the bulk of dual strings that can incorporate intrinsic spins of fundamental QCD degrees of freedom. We also comment on the interesting issue of the size of mesons in holographic QCD.
Sharma, Neelesh; Verma, R. C.; Dhir, Rohit
2011-01-01
In this paper, we investigate phenomenologically two-body weak decays of the bottom mesons emitting pseudoscalar/vector meson and a tensor meson. Form factors are obtained using the improved Isgur-Scora-Grinstein-Wise II model. Consequently, branching ratios for the Cabibbo-Kobayashi-Maskawa-favored and Cabibbo-Kobayashi-Maskawa-suppressed decays are calculated.
Issues in light meson spectroscopy: The case for meson spectroscopy at CEBAF
Godfrey, S.
1994-04-01
The author reviews some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional q{bar q} mesons. The author therefore begins by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section the author discusses the opportunities that CEBAF can offer for the study of meson spectroscopy.
Summary of the [eta]-meson sessions
Chrien, R.E.
1993-01-01
This summary describes the contents of the nineteen talks related to research on the [eta] meson and presented at the Workshop of Future Directions. The subjects of this area include threshold [eta] production, [eta]-nuclear spectroscopy, baryon spectroscopy, [eta] decays, facilities, and instrumentation.
Summary of the {eta}-meson sessions
Chrien, R.E.
1993-06-01
This summary describes the contents of the nineteen talks related to research on the {eta} meson and presented at the Workshop of Future Directions. The subjects of this area include threshold {eta} production, {eta}-nuclear spectroscopy, baryon spectroscopy, {eta} decays, facilities, and instrumentation.
Coherent ω-Meson Photoproduction off Deuteron
NASA Astrophysics Data System (ADS)
Chetry, Taya; Hicks, Kenneth; CLAS Collaboration
2016-03-01
Coherent ω photoproduction from the deuteron has been studied using CLAS at Jefferson Lab, Virginia, as a function of the photon energy and the 4-momentum transfer. Tagged photons with beam energies between 0.8 and 3.6 GeV were produced using the bremsstrahlung process incident on a deuterium target, during the run period g10. The final state particles detected are an energetic deuteron and a pair of charged pions. These events were constrained to have neutral pion missing mass, to ensure an exclusive reaction where an ω-meson decays into a π+, a π- and a π0. This study allows to test models of hadronic scattering of ω-mesons from the nucleon, as it is not possible to produce beams of ω-mesons. A preliminary differential cross section of the ω-meson in the coherent process is presented. In addition, this final state is useful to investigate a possible d* dibaryon resonance that has been seen in other reaction channels at CLAS, as well as being seen earlier in partial-wave analysis of pion-deuteron scattering at a mass of about 2145 MeV.
Monte Carlo Nucleon Meson Transport Code System.
Energy Science and Technology Software Center (ESTSC)
2000-11-17
Version 00 NMTC/JAERI97 is an upgraded version of the code system NMTC/JAERI, which was developed in 1982 at JAERI and is based on the CCC-161/NMTC code system. NMTC/JAERI97 simulates high energy nuclear reactions and nucleon-meson transport processes.
Extracting excited mesons from the finite volume
Doring, Michael
2014-12-01
As quark masses come closer to their physical values in lattice simulations, finite volume effects dominate the level spectrum. Methods to extract excited mesons from the finite volume are discussed, like moving frames in the presence of coupled channels. Effective field theory can be used to stabilize the determination of the resonance spectrum.
Charmonium meson and hybrid radiative transitions
Guo, Peng; Yépez-Martínez, Tochtli; Szczepaniak, Adam P.
2014-06-01
We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of cc¯ hybrids to charmonium mesons. The results are compared to potential quark models and lattices calculations.
QED effects in the pseudoscalar meson sector
NASA Astrophysics Data System (ADS)
Horsley, R.; Nakamura, Y.; Perlt, H.; Pleiter, D.; Rakow, P. E. L.; Schierholz, G.; Schiller, A.; Stokes, R.; Stüben, H.; Young, R. D.; Zanotti, J. M.
2016-04-01
In this paper we present results on the pseudoscalar meson masses from a fully dynamical simulation of QCD+QED, concentrating particularly on violations of isospin symmetry. We calculate the π +- π 0 splitting and also look at other isospin violating mass differences. We have presented results for these isospin splittings in [1]. In this paper we give more details of the techniques employed, discussing in particular the question of how much of the symmetry violation is due to QCD, arising from the different masses of the u and d quarks, and how much is due to QED, arising from the different charges of the quarks. This decomposition is not unique, it depends on the renormalisation scheme and scale. We suggest a renormalisation scheme in which Dashen's theorem for neutral mesons holds, so that the electromagnetic self-energies of the neutral mesons are zero, and discuss how the self-energies change when we transform to a scheme such as overline{M S} , in which Dashen's theorem for neutral mesons is violated.
[ital CPT], strings, and meson factories
Kostelecky, V.A. ); Potting, R. )
1995-04-01
Spontaneous breaking of [ital CPT] is possible in string theory. We show that it can arise at a level within reach of experiments at meson factories currently being built or designed. For [phi], [ital B], and [tau]-charm factories, we discuss the likely experimental string signatures and provide estimates of the bounds that might be attained in these machines.
CPT violation and B-meson oscillations
Kostelecky, V. Alan; Van Kooten, Richard J.
2010-11-15
Recent evidence for anomalous CP violation in B-meson oscillations can be interpreted as resulting from CPT violation. This yields the first sensitivity to CPT violation in the B{sub s}{sup 0} system, with the relevant coefficient for CPT violation constrained at the level of parts in 10{sup 12}.
Meson wave function from holographic models
Vega, Alfredo; Schmidt, Ivan; Branz, Tanja; Gutsche, Thomas; Lyubovitskij, Valery E.
2009-09-01
We consider the light-front wave function for the valence quark state of mesons using the AdS/CFT correspondence, as has been suggested by Brodsky and Teramond. Two kinds of wave functions, obtained in different holographic Soft-Wall models, are discussed.
Charming Mesons with Baryons and Nuclei
NASA Astrophysics Data System (ADS)
Tolos, Laura
2013-11-01
The properties of charmed mesons in nuclear matter and nuclei are reviewed. Different frameworks are discussed paying a special attention to unitarized coupled-channel approaches which incorporate heavy-quark spin symmetry. Several charmed baryon states with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2+ and 3/2+ baryons. These states are compared to experimental data. Moreover, the properties of open-charm mesons in matter are analyzed. The in-medium solution accounts for Pauli blocking effects, and for the meson self-energies in a self-consistent manner. The behavior in the nuclear medium of the rich spectrum of dynamically-generated baryon states is studied as well as their influence in the self-energy and, hence, the spectral function of open charm. The possible experimental signatures of the in-medium properties of open charm are finally addressed, such as the formation of charmed nuclei, in connection with the future FAIR facility.
Skyrmions and vector mesons: a symmetric approach
Caldi, D.G.
1984-01-01
We propose an extension of the effective, low-energy chiral Lagrangian known as the Skyrme model, to one formulated by a non-linear sigma model generalized to include vector mesons in a symmetric way. The model is based on chiral SU(6) x SU(6) symmetry spontaneously broken to static SU(6). The rho and other vector mesons are dormant Goldstone bosons since they are in the same SU(6) multiplet as the pion and other pseudoscalars. Hence the manifold of our generalized non-linear sigma model is the coset space (SU(6) x SU(6))/Su(6). Relativistic effects, via a spin-dependent mass term, break the static SU(6) and give the vectors a mass. The model can then be fully relativistic and covariant. The lowest-lying Skyrmion in this model is the whole baryonic 56-plet, which splits into the octet and decuplet in the presence of relativistic SU(6)-breaking. Due to the built-in SU(6) and the presence of vector mesons, the model is expected to have better phenomenological results, as well as providing a conceptually more unified picture of mesons and baryons. 29 references.
Meson Spectroscopy at JLab@12 GeV
Celentano, Andrea
2013-03-01
Meson, being the simplest hadronic bound system, is the ideal "laboratory" to study the interaction between quarks, to understand the role of the gluons inside hadrons and to investigate the origin of color confinement. To perform such studies it is important to measure the meson spectrum, with precise determination of resonance masses and properties, looking for rare qbar q states and for unconventional mesons with exotic quantum numbers (i.e. mesons with quantum numbers that are not compatible with a qbar q structure). With the imminent advent of the 12 GeV upgrade of Jefferson Lab a new generation of meson spectroscopy experiments will start: "Meson-Ex" in Hall B and "GLUEX" in Hall D. Both will use photo-production to explore the spectrum of mesons in the light-quark sector, in the energy range of few GeVs.
Spin O decay angular distribution for interfering mesons in electroproduction
Funsten, H.; Gilfoyle, G.
1994-04-01
Self analyzing meson electroproduction experiments are currently being planned for the CEBAF CLAS detector. These experiments deduce the spin polarization of outgoing unstable spin s (?)0 mesons from their decay angular distribution, W({theta},{psi}). The large angular acceptance of the CLAS detector permits kinematic tracking of a sufficient number of these events to accurately determine electroproduction amplitudes from the deduced polarization. Maximum polarization information is obtained from W({theta},{psi}) for decay into spin 0 daughters. The helicity of the decaying meson is transferred to the daughter`s relative orbital angular momentum m-projection; none is {open_quotes}absorbed{close_quotes} into daughter helicities. The decaying meson`s helicity maximally appears in W({theta},{psi}). W({theta},{psi}) for spin 0 daughters has been derived for (1) vector meson electroproduction and (2) general interfering mesons produced by incident pions. This paper derives W({theta},{psi}) for electroproduction of two interfering mesons that decay into spin 0 daughters. An application is made to the case of interfering scalar and vector mesons. The derivation is an extension of work by Schil using the general decay formalism of Martin. The expressions can be easily extended to the case of N interfering mesons since interference occurs pairwise in the observable W ({theta},{psi}), a quadratic function of the meson amplitudes. The derivation uses the virtual photon density matrix of Schil which is transformed by a meson electroproduction transition operator, T. The resulting density matrix for the interfering mesons is then converted into a corresponding statistical tensor and contracted into the efficiency tensor for spin 0 daughters.
Decays of doubly charmed meson molecules
NASA Astrophysics Data System (ADS)
Molina, R.; Nagahiro, H.; Hosaka, A.
2016-01-01
If the X(3872), Y(3940) and X(4160) are D*D ¯+c .c ., D*D ¯* and DS*D¯S* molecules, respectively, there should be doubly charmed mesons (D(*)D(*)). In this talk we predict two states with JP = 1+ in the charm = 2 sector, one DD* state around 3850 MeV, other D*D* state with mass around 3970 MeV, and other two similar states in the (charm = 2; strangeness = sector. Besides that, we evaluate the decay widths of doubly charm mesons D*D*(1+), into DDπ and DDγ. These decays are mediated by anomalous couplings D*D* - DD*, with the subsequent decay of D* into Dπ or Dγ.
Time reversal violation for entangled neutral mesons
NASA Astrophysics Data System (ADS)
Bernabéu, J.
2013-07-01
A direct evidence for Time Reversal Violation (TRV) means an experiment that, considered by itself, clearly shows TRV independent of, and unconnected to, the results for CP Violation. No existing result before the recent BABAR experiment with entangled neutral B mesons had demonstrated TRV in this sense. There is a unique opportunity for a search of TRV with unstable particles thanks to the Einstein-Podolsky-Rosen (EPR) Entanglement between the two neutral mesons in B, and PHI, Factories. The two quantum effects of the first decay as a filtering measurement and the transfer of information to the still living partner allow performing a genuine TRV asymmetry with the exchange of "in" and "out" states. With four independent TRV asymmetries, BABAR observes a large deviation of T-invariance with a statistical significance of 14 standard deviations, far more than needed to declare the result as a discovery. This is the first direct observation of TRV in the time evolution of any system.
Semileptonic B-Meson Decays at Babar
NASA Astrophysics Data System (ADS)
Sigamani, Michael
2011-10-01
Presented are selected results from semileptonic B-meson decays at BABAR. Two measurements of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| are reported, using moments of the hadronic-mass spectrum in inclusive bar B -> Xc l ^ - bar v decays, and also exclusive bar B -> Dl ^ - bar vl decays. These results are based on data samples of 232 (inclusive bar B -> Xc l ^ - bar v) and 460 (exclusive bar B -> Dl ^ - bar vl ) million Υ (4S) -> Bbar B decays recorded by the BABAR detector at the PEP-II e+e-storage rings. Semileptonic events are identified by requiring a lepton (e or μ) in events tagged by a full reconstruction of one of the B mesons in the Bbar B pair.
Meson exchange and neutral weak currents
Beck, D.H.
1994-04-01
Measurements of parity-violating electron scattering asymmetries to determine weak neutral currents in nuclei will be effected by the presence of meson exchange currents. Present low momentum transfer calculations, based on a flavor independent framework, show these effects to be small. In general, however, as the momentum transfer increases to values typical of deep-inelastic scattering, fragmentation functions show a clear flavor dependence. It is suggested that a good experimental starting point for understanding the flavor dependence of meson production and exchange currents is the Q{sup 2} dependence of parity-violating asymmetry in inclusive single pion electroproduction. A CEBAF facility with doubled energy is necessary to approach momentum transfers where this process begins to scale.
Production of polarized vector mesons off nuclei
Kopeliovich, B. Z.; Nemchik, J.; Schmidt, Ivan
2007-08-15
Using the light-cone QCD dipole formalism we investigate manifestations of color transparency (CT) and coherence length (CL) effects in electroproduction of longitudinally (L) and transversally (T) polarized vector mesons. Motivated by forthcoming data from the HERMES experiment we predict both the A and Q{sup 2} dependence of the L/T ratios for {rho}{sup 0} mesons produced coherently and incoherently off nuclei. For an incoherent reaction the CT and CL effects add up and result in a monotonic A dependence of the L/T ratio at different values of Q{sup 2}. In contrast, for a coherent process the contraction of the CL with Q{sup 2} causes an effect opposite to that of CT and we expect quite a nontrivial A dependence.
Weak Decays of Excited B Mesons
NASA Astrophysics Data System (ADS)
Grinstein, B.; Martin Camalich, J.
2016-04-01
We investigate the decays of the excited (b q ¯) mesons as probes of the short-distance structure of the weak Δ B =1 transitions. These states are unstable under the electromagnetic or strong interactions, although their widths are typically suppressed by phase space. Compared to the pseudoscalar B meson, the purely leptonic decays of the vector B* are not chirally suppressed and are sensitive to different combinations of the underlying weak effective operators. An interesting example is Bs*→ℓ+ℓ-, which has a rate that can be accurately predicted in the standard model. The branching fraction is B ˜10-11, irrespective of the lepton flavor and where the main uncertainty stems from the unmeasured and theoretically not well known Bs* width. We discuss the prospects for producing this decay mode at the LHC and explore the possibility of measuring the Bs*→ℓℓ amplitude, instead, through scattering experiments at the Bs* resonance peak.
Electroproduction of tensor mesons in QCD
NASA Astrophysics Data System (ADS)
Braun, V. M.; Kivel, N.; Strohmaier, M.; Vladimirov, A. A.
2016-06-01
Due to multiple possible polarizations hard exclusive production of tensor mesons by virtual photons or in heavy meson decays offers interesting possibilities to study the helicity structure of the underlying short-distance process. Motivated by the first measurement of the transition form factor γ∗γ → f 2(1270) at large momentum transfers by the BELLE collaboration we present an improved QCD analysis of this reaction in the framework of collinear factorization including contributions of twist-three quark-antiquark-gluon operators and an estimate of soft end-point corrections using light-cone sum rules. The results appear to be in good agreement with the data, in particular the predicted scaling behavior is reproduced in all cases.
The lightest hybrid meson supermultiplet in QCD
Dudek, Jozef J
2011-10-01
We interpret the spectrum of meson states recently obtained in non-perturbative lattice QCD calculations in terms of constituent quark-antiquark bound states and states, called 'hybrids', in which the q{bar q} pair is supplemented by an excitation of the gluonic field. We identify a lightest supermultiplet of hybrid mesons with J{sup PC} = (0,1,2){sup {-+}}, 1{sup -} built from a gluonic excitation of chromomagnetic character coupled to q{bar q} in an S-wave. The next lightest hybrids are suggested to be quark orbital excitations with the same gluonic excitation, while the next distinct gluonic excitation is significantly heavier. Existing models of gluonic excitations are compared to these findings and possible phenomenological consequences explored.
Non-conventional mesons at PANDA
NASA Astrophysics Data System (ADS)
Giacosa, Francesco
2015-04-01
Non-conventional mesons, such as glueballs and tetraquarks, will be in the focus of the PANDA experiment at the FAIR facility. In this lecture we recall the basic properties of QCD and describe some features of unconventional states. We focus on the search of the not-yet discovered glueballs and the use of the extended Linear Sigma Model for this purpose, and on the already discovered but not-yet understood X, Y, Z states.
Electromagnetic charge radii of pseudoscalar mesons
Bagchi, B.; Lahiri, A.; Niyogi, S.
1989-06-01
The charge radii of the pseudoscalar mesons ..pi../sup +/, /ital K//sup +/, and /ital K//sup 0/ are analyzed in an extended vector-dominance framework and the results are compared with those which follow the nonrelativistic quark model and constituent-quark triangle loop approach. Further, estimates of the root-mean-square relative coordinate parameter are obtained which are in conformity with normal theoretical expectations.
Understanding the baryon and meson spectra
Pennington, Michael R.
2013-10-01
A brief overview is given of what we know of the baryon and meson spectra, with a focus on what are the key internal degrees of freedom and how these relate to strong coupling QCD. The challenges, experimental, theoretical and phenomenological, for the future are outlined, with particular reference to a program at Jefferson Lab to extract hadronic states in which glue unambiguously contributes to their quantum numbers.
Strangeness and meson-nucleon sigma terms
Dahiya, Harleen; Sharma, Neetika
2011-10-21
The chiral constituent quark model ({chi}CQM) has been extended to calculate the flavor structure of the nucleon through the meson-nucleon sigma terms which have large contributions from the quark sea and are greatly affected by chiral symmetry breaking and SU(3) symmetry breaking. The hidden strangeness component in the nucleon has also been investigated and its significant contribution is found to be consistent with the recent available experimental observations.
Rare B Meson Decays at the Tevatron
Hopkins, Walter
2012-01-01
Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the b {yields} s{mu}{sup +}{mu}{sup -} and B{sub s,d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays. We report recent results at a center of mass energy of {radical}s = 1.96 TeV from CDF II using 7 fb{sup -1} at the Fermilab Tevatron Collider.
Mesonic spectroscopy of minimal walking technicolor
Del Debbio, Luigi; Lucini, Biagio; Patella, Agostino; Pica, Claudio; Rago, Antonio
2010-07-01
We investigate the structure and the novel emerging features of the mesonic nonsinglet spectrum of the minimal walking technicolor theory. Precision measurements in the nonsinglet pseudoscalar and vector channels are compared to the expectations for an IR-conformal field theory and a QCD-like theory. Our results favor a scenario in which minimal walking technicolor is (almost) conformal in the infrared, while spontaneous chiral symmetry breaking seems less plausible.
Helicity operators for mesons in flight on the lattice
Christopher E. Thomas; Edwards, Robert G.; Dudek, Jozef J.
2012-01-20
Motivated by the desire to construct meson-meson operators of definite relative momentum in order to study resonances in lattice QCD, we present a set of single-meson interpolating fields at non-zero momentum that respect the reduced symmetry of a cubic lattice in a finite cubic volume. These operators follow from the subduction of operators of definite helicity into irreducible representations of the appropriate little groups. We show their effectiveness in explicit computations where we find that the spectrum of states interpolated by these operators is close to diagonal in helicity, admitting a description in terms of single-meson states of identified J^{PC}. Lastly, the variationally determined optimal superpositions of the operators for each state give rapid relaxation in Euclidean time to that state, ideal for the construction of meson-meson operators and for the evaluation of matrix elements at finite momentum.
Towards a Theoretical Understanding of the XYZ Mesons from QCD
NASA Astrophysics Data System (ADS)
Braaten, Eric
2016-03-01
The XYZ mesons are mesons that contain a heavy quark and antiquark but have properties that seem to require additional constituents. Some of them are electrically charged, so they must be tetraquark mesons whose additional constituents are a light quark and antiquark. The list of XYZ mesons has grown to about two dozen over the last decade. A promising approach to understanding these mesons within QCD is the Born-Oppenheimer approximation, which reduces the problem to the solution of the Schrödinger equation in potentials that can be calculated using lattice QCD. The Born-Oppenheimer approximation has not yet revealed the pattern of the XYZ mesons, but it provides a compelling framework for understanding them from the fundamental theory.
Radius of the ρ meson determined from its decay constant
NASA Astrophysics Data System (ADS)
Krutov, A. F.; Polezhaev, R. G.; Troitsky, V. E.
2016-02-01
We present a unified model describing electroweak properties of the π and ρ mesons. Using a general method of the relativistic parametrization of matrix elements of local operators, adjusted for the nondiagonal in the total angular momentum case, we calculate the ρ -meson lepton-decay constant fρ using the same parameters of free constituent quarks that have ensured exclusively good results for the π meson previously. The only free parameter, characterizing quark interactions, which include an additional spin-spin contribution and hence differ from the π -meson case, is fixed by matching the decay constant to its experimental value. The mean square charge radius is calculated, ⟨rρ2⟩=(0.56 ±0.04 ) fm2 . This result confirms, for the ρ -meson case, the conjecture of equality between electromagnetic and strong radii of hadrons. This conjecture was tested previously for proton, π and K mesons.
Helicity operators for mesons in flight on the lattice
Christopher E. Thomas; Edwards, Robert G.; Dudek, Jozef J.
2012-01-20
Motivated by the desire to construct meson-meson operators of definite relative momentum in order to study resonances in lattice QCD, we present a set of single-meson interpolating fields at non-zero momentum that respect the reduced symmetry of a cubic lattice in a finite cubic volume. These operators follow from the subduction of operators of definite helicity into irreducible representations of the appropriate little groups. We show their effectiveness in explicit computations where we find that the spectrum of states interpolated by these operators is close to diagonal in helicity, admitting a description in terms of single-meson states of identified JPC.more » Lastly, the variationally determined optimal superpositions of the operators for each state give rapid relaxation in Euclidean time to that state, ideal for the construction of meson-meson operators and for the evaluation of matrix elements at finite momentum.« less
Time reversal violation for entangled neutral mesons
Bernabeu, J.
2014-07-23
A direct evidence for Time Reversal Violation (TRV) means an experiment that, considered by itself, clearly shows TRV independent of, and unconnected to, the results for CP Violation. No existing result before the recent BABAR experiment with entangled neutral B mesons had demonstrated TRV in this sense. There is a unique solution for the test of TRV with unstable particles thanks to the Einstein-Podolsky-Rosen (EPR) Entanglement between the two neutral mesons in B, and φ, Factories. The two quantum effects of the decays as filtering measurements of the meson states and the transfer of information of the first decay to the still living partner allow performing a genuine TRV asymmetry with the exchange of “in” and “out” states. With four independent TRV asymmetries, BABAR observes a large deviation of T-invariance with a statistical significance of 14 standard deviations, far more than needed to declare the result as a discovery. This is the first direct observation of TRV in the time evolution of any system. The perspectives for future additional studies of TRV are discussed.
Time reversal violation for entangled neutral mesons
NASA Astrophysics Data System (ADS)
Bernabeu, J.
2014-07-01
A direct evidence for Time Reversal Violation (TRV) means an experiment that, considered by itself, clearly shows TRV independent of, and unconnected to, the results for CP Violation. No existing result before the recent BABAR experiment with entangled neutral B mesons had demonstrated TRV in this sense. There is a unique solution for the test of TRV with unstable particles thanks to the Einstein-Podolsky-Rosen (EPR) Entanglement between the two neutral mesons in B, and φ, Factories. The two quantum effects of the decays as filtering measurements of the meson states and the transfer of information of the first decay to the still living partner allow performing a genuine TRV asymmetry with the exchange of "in" and "out" states. With four independent TRV asymmetries, BABAR observes a large deviation of T-invariance with a statistical significance of 14 standard deviations, far more than needed to declare the result as a discovery. This is the first direct observation of TRV in the time evolution of any system. The perspectives for future additional studies of TRV are discussed.
Hard Exclusive Meson Production at COMPASS
NASA Astrophysics Data System (ADS)
Ter Wolbeek, Johannes
2016-02-01
The concept of Generalized Parton Distributions (GPDs) combines two-dimensional spatial information given by form factors, with longitudinal momentum information from Parton Distribution Functions. GPDs provide comprehensive description of the nucleon structure involving a wealth of new information. For instance, according to Ji’s sum rule, the GPDs H and E enable access to the total angular momenta of quarks, antiquarks and gluons. While H can be approached using measurements of electroproduction cross sections, asymmetry measurements in hard exclusive meson production off transversely polarized targets can help to constrain the GPD E and chiral-odd GPDs. In 2007 and 2010 the COMPASS experiment at CERN collected data by scattering a 160GeV/c muon beam off a transversely polarized NH3 target. Exclusive vector-meson production μ + p → μ‧ + p + V with a ρ0 or ω meson in the final state is studied and five single-spin and three double-spin azimuthal asymmetries are measured.
Vector Meson Form Factors and Wave Functions from Holographic QCD
Hovhannes Grigoryan; Anatoly Radyushkin
2007-10-10
Based on the holographic dual model of QCD, we study 2- and 3-point functions of vector currents and derive form factors as well as wave functions for the vector mesons. As a result, generalized vector-meson dominance representation for form factors is obtained with a very specific VMD pattern. The calculated electric radius of the rho-meson is shown to be in a good agreement with predictions from lattice QCD.
Search for medium effects on light vector mesons
Djalali, C; Nasseripour, R; Weygand, D P; Wood, M H
2007-02-01
The photoproduction of vector mesons on various nuclei has been studied using the Cebaf Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. The rho, omega, and phi mesons are observed via their decay to e^{+}e^{₋}. The rho spectral function is extracted from the data on carbon, iron, and titanium. We observe no effects on the mass of the rho meson, some widening in titanium and iron is observed consistent with standard collisional broadening.
The Meson Spectroscopy Program at the Jefferson Laboratory
Filippi, Alessandro
2015-06-01
The experimental techniques that will be applied by the next generation meson spectroscopy experiments at JLab are described. For the first time, these experiments will be able to exploit the features of a photon beam of unprecedented intensity and momentum resolution, that will allow to perform precision studies of meson states with masses below 3 GeV/c^{2}. Photon induced reactions will enhance the production of spin-1 mesons, that are of particular interest according to the most recent Lattice QCD calculations of the lightest exotic hybrid meson.
Phi meson propagation in a hot hadronic gas
Alvarez-Ruso, Luis; Koch, Volker
2002-02-20
The Hidden Local Symmetry Lagrangian is used to study the interactions of phi mesons with other pseudoscalar and vector mesons in a hadronic gas at finite temperature. We have found a significantly small phi mean free path (less than 2.4 fm at T > 170 MeV) due to large collision rates with rho mesons, kaons and predominantly K* in spite of their heavy mass. This implies that phi mesons produced after hadronization in relativistic heavy ion collisions will not leave the hadronic system without scattering. The effect of these interactions on the time evolution of the phi density in the expanding hadronic fireball is investigated.
Search for gluonic excitations in light unconventional mesons
Paul Eugenio
2007-07-01
Studies of meson spectra via strong decays provide insight regarding QCD at the confinement scale. These studies have led to phenomenologicalmodels for QCD such as the constituent quark model. However, QCD allows for a much richer spectrum of meson states which include extra states such as exotics, hybrids, multi-quarks, and glueballs. First discussion of the status of exotic meson searches is given followed by a discussion of plans at Jefferson Lab to double the energy of the machine to 12 GeV, which will allow us to access photoproduction of mesons in search for gluonic excited states.
Scattering amplitudes to all orders in meson exchange
Silbar, R.R.; Mattis, M.P.
1990-01-01
As the number of colors in QCD, N{sub C}, becomes large, it is possible to sum up all meson-exchange contributions, however arbitrarily complicated, to meson-baryon and baryon-baryon scattering. A semi-classical structure for the two-flavor theory emerges, in close correspondence to vector-meson-augmented Skyrme models. In this limit, baryons act as extended static sources for the classical meson fields. This leads to non-linear differential equations for the classical meson fields which can be solved numerically for static radial (hedgehog-like) solutions. The non-linear terms in the equations of motion for the quantized meson fields can then be simplified, to leading order in 1/N{sub C}, by replacing all factors of the meson field but one by the previously-found classical field. This results in linear, Schroedinger-like equations, which are easily solved. For the meson-baryon case the solution can be subsequently analyzed to obtain the phase shifts for the scattering and, from these, the baryon resonance spectrum of the model. As the warm-up, we have carried out this calculation for the simple case of {sigma} mesons only, finding sensible results. 8 refs., 3 figs.
In-medium properties of light vector mesons
C. Djalali; R. Nasseripour; D. P. Weygand; M. H. Wood
2007-08-01
The photoproduction of vector mesons on various nuclei has been studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. All three vector mesons ρ, ω and phi are observed via their decay to e+e-. The possible in-medium effects on the properties of the ρ meson are of particular interest. The ρ spectral function is extracted from the data on carbon, iron and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no effects on the mass of the ρ meson, some widening in titanium and iron is observed consistent with the collisional broadening.
Search for medium modifications of the rho meson.
Nasseripour, R; Wood, M H; Djalali, C; Weygand, D P; Tur, C; Mosel, U; Muehlich, P; Adams, G; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Battaglieri, M; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Carnahan, B; Casey, L; Chen, S; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; Dashyan, N; De Masi, R; De Vita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Dickson, R; Dodge, G E; Doughty, D; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Feldman, G; Feuerbach, R J; Funsten, H; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gordon, C I O; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Li, Ji; Livingston, K; Lu, H Y; Maccormick, M; Markov, N; Mattione, P; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mehrabyan, S; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Mueller, J; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Sabatié, F; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S S; Stepanyan, S; Stokes, B E; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Todor, L; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Weinstein, L B; Williams, M; Wolin, E; Yegneswaran, A; Zana, L; Zhang, B; Zhang, J; Zhao, B; Zhao, Z W
2007-12-31
The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and varphi, are observed via their decay to e;{+}e;{-}, in order to reduce the effects of final-state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, 2H, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson. PMID:18233570
Barnes, T. |
1992-12-31
In this talk I summarize recent calculations of meson-meson scattering amplitudes in the nonrelativistic quark potential model, which assume that the scattering mechanism is one-gluon-exchange followed by constituent exchange (OGE+CEX). We refer to the scattering diagrams as ``quark Born diagrams``. For the cases chosen to isolate this mechanism, I=2 {pi}{pi} and I=3/2 K{pi}, the theoretical results are in remarkably good agreement with experimental S- and P-wave phase shifts and PCAC scattering lengths, given standard potential-model parameters.
Barnes, T. Tennessee Univ., Knoxville, TN . Dept. of Physics)
1992-01-01
In this talk I summarize recent calculations of meson-meson scattering amplitudes in the nonrelativistic quark potential model, which assume that the scattering mechanism is one-gluon-exchange followed by constituent exchange (OGE+CEX). We refer to the scattering diagrams as quark Born diagrams''. For the cases chosen to isolate this mechanism, I=2 [pi][pi] and I=3/2 K[pi], the theoretical results are in remarkably good agreement with experimental S- and P-wave phase shifts and PCAC scattering lengths, given standard potential-model parameters.
The hybrid mesons quest: the MesonEx experiment at Jefferson Laboratory
NASA Astrophysics Data System (ADS)
Rizzo, A.; CLAS Collaboration
2016-02-01
The meson spectroscopy plays nowadays a central role in the investigation of hadron structure thanks to the possible existence of exotic hybrid mesons, quark-antiquark-gluon bound states. Their explicit gluonic degrees of freedom which should clearly emerge from a Partial Wave Analysis (PWA) of the corresponding Dalitz plot of the exotic particle decay, may result in final JPC configurations not allowed in the constituent quark model. Besides this clear signature, hybrid mesons are also expected to have a large particle multiplicity decays, requiring for their search an experimental apparatus with high performances in terms of rate capability, resolution and almost a full acceptance to apply PWA methods. New-generation experiments are planned at Thomas Jefferson National Laboratory (VA, USA) for which an unprecedented statistics of large multiplicity decay events with fully reconstructed kinematics will be available. In particular for the MesonEx (CLAS12) experiment in Hall B, a wide scientific program that will start in 2016 has been deployed to study the meson spectrum at energies up to 11 GeV. A key role in such program is played by the Forward Tagger apparatus of the experiment, which will allow to extend the study of meson electro-production to very low Q2 values, in a quasi-real photo production kinematical region, where the production of hybrid mesons is expected to be favorite. Currently a new analysis framework for the search of the hybrid mesons is being set up by the HASPECT network, an international structure which gather people involved into theoretical and experimental hadronic physics all over the world. The goals of the network is to develop new analysis models and statistical techniques to unfold the signal and background distributions in high-statistics datasets. In this work are briefly presented the first preliminary results from the application of a statistical technique, namely the sPlot, to the data already acquired by the CLAS experiment for
Decay constants of p and d wave heavy light mesons
Veseli, Sinisa; Dunietz, Isard
1996-07-01
We investigate decay constants of P- and D-wave heavy-light mesons within the mock-meson approach. Numerical estimates are obtained using the relativistic quark model. We also comment on recent calculations of heavy-light pseudo-scalar and vector decay constants.
Absorption of the omega and phi mesons in nuclei
Chaden Djalali, Michael H. Wood, Michael Paolone, Rakhsha Nasseripour, Dennis P. Weygand
2012-04-01
The properties of hadrons, such as their masses and widths, are predicted to be modified in dense and/or hot nuclear matter. Particular attention has been given to the modifications of vector-meson properties in ordinary nuclear matter where chiral symmetry is predicted to be partially restored due to a change in the quark condensate. Different models predict relatively large measurable changes in the mass and/or the width of these mesons. The e{sup +}e{sup -} decay channel of these mesons has negligible final-state interactions (FSI), providing an ideal tool to study their possible in-medium modifications Due to its short lifetime, the {rho} meson has a substantial probability of decaying in the nucleus and its study has been previously reported. Due to their long lifetimes, the {omega} and {phi} mesons are ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. These mesons have been photo-produced in several targets ranging from deuterium to lead. Nuclear transparencies ratios have been derived for different decay channels. These ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the {omega} meson is stronger than that reported by the CBELSATAPS experiment. These results are compared to recent theoretical models.
First measurement of the B S meson mass
NASA Astrophysics Data System (ADS)
Buskulic, D.; De Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Veenhof, R.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jacobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; St. Denis, R.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Gao, Y.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; LeClaire, B. W.; Lishka, C.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Sharma, V.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.
1993-07-01
In a sample of about 1.1 million hadronic Z decays recorded with the ALEPH detector during the 1990-1992 running of LEP, two unambiguous B S meson candidates were observed. From these events the mass of the B S meson has been measured to be 5.3686 ± 0.0056 (stat.) ± 0.0015 (syst.) GeV.
New-particle spectroscopy, quarkonium and gluonic mesons
Bloom, E.D.
1982-10-01
Recent experimental results on quarkonium and gluonic mesons are presented and discussed. Comparisons with theory are made. Quarkonium predictions seem to agree well with experiment. The question of the experimental verification of gluonic mesons is clouded by the difficulty of the theoretical interpretation.
Beauty vector meson decay constants from QCD sum rules
NASA Astrophysics Data System (ADS)
Lucha, Wolfgang; Melikhov, Dmitri; Simula, Silvano
2016-01-01
We present the outcomes of a very recent investigation of the decay constants of nonstrange and strange heavy-light beauty vector mesons, with special emphasis on the ratio of any such decay constant to the decay constant of the corresponding pseudoscalar meson, by means of Borel-transformed QCD sum rules. Our results suggest that both these ratios are below unity.
Status of Meson Photoproduction Experiments with CLAS
Pasyuk, Eugene A.
2014-01-01
A large part of the experimental program in Hall B of the Jefferson Lab is dedicated to baryon spectroscopy. Meson photoproduction experiments are essential part of this program. CEBAF Large Acceptance Spectrometer (CLAS) and availability of circularly and linearly polarized tagged photon beams in combination with longitudinally and transversely polarized frozen spin targets provide unique conditions for this type of experiments. For the first time, a complete or nearly complete measurement became possible and will allow model independent extraction of the reaction amplitude. The measurements were complete with both proton and deuteron targets. An overview of the collected experimental data will be presented.
Rare B meson decays at the Tevatron
Hopkins, Walter; /Cornell U., Phys. Dept.
2011-08-01
Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the B{sub s,d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and b {yields} s{mu}{sup +}{mu}{sup -} decays. We report recent results at a center of mass energy of {radical}s = 1.96 TeV from the CDF II and D0 collaborations using between 3.7 fb{sup -1} and 6.9 fb{sup -1} taken during Run II of the Fermilab Tevatron Collider.
Meson Photoproduction Experiments at ELPH, Tohoku University
NASA Astrophysics Data System (ADS)
Ishikawa, Takatsugu; Fujimura, Hisako; Fukasawa, Hiroshi; Hashimoto, Ryo; He, Qinghua; Honda, Yuki; Iwata, Takahiro; Kaida, Shun; Kasagi, Jirohta; Kawano, Atsushi; Kuwasaki, Shuzo; Maeda, Kazushige; Masumoto, Shin'ichi; Miyabe, Manabu; Miyahara, Fusashi; Mochizuki, Kei'ichi; Muramatsu, Norihito; Nakamura, Akihiko; Nawa, Ken'ichi; Ogushi, Shoei; Okada, Yasuyuki; Onodera, Yoshihito; Ozawa, Kyoichiro; Sakamoto, Yasunobu; Sato, Mamoru; Shimizu, Hajime; Sugai, Hiroyuki; Suzuki, Koutaku; Tajima, Yasuhisa; Takahashi, Shin'ichiro; Taniguchi, Yusuke; Tsuchikawa, Yusuke; Yamazaki, Hirohito; Yamazaki, Ryuji; Yoshida, Hiroshi Y.
Meson photoproduction experiments have been conducted with an electromagnetic (EM) calorimeter FOREST at Research Center for Electron Photon Science (ELPH), Tohoku University. A narrow resonance observed at W = 1670 MeV in η photoproduction on the neutron is of great interest, which is a candidate of an anti-decuplet pentaquark baryon although its origin is still controversial. The preliminary results of the cross sections for π0 and η photoproduction on the deuteron are presented. The next generation FOREST experiments have been planned to study S11(1535) properties in the nuclear medium by searching for η-mesic nucleus states. The planned experiments are also shown in this contribution.
Scalar Mesons, Multiquark States and Supersymmetry
Catto, Sultan
2008-08-31
Quark models with potentials derived from QCD, including the quark-diquark model for excited hadrons leading to a symmetry between mesons and baryons gives mass formulae in very good agreement with experiment and goes a long way in explaining the approximate symmetries and supersymmetries of the hadronic spectrum, including the symmetry breaking mechanism. We give a description of the only algebra describing color degrees of freedom based on split octonionic units and leading to a mathematical understanding of formation of diquarks as well as multiquark states.
Theoretical aspects of light meson spectroscopy
Barnes, T. |
1995-12-31
In this pedagogical review the authors discuss the theoretical understanding of light hadron spectroscopy in terms of QCD and the quark model. They begin with a summary of the known and surmised properties of QCD and confinement. Following this they review the nonrelativistic quark potential model for q{anti q} mesons and discuss the quarkonium spectrum and methods for identifying q{anti q} states. Finally, they review theoretical expectations for non-q{anti q} states (glueballs, hybrids and multiquark systems) and the status of experimental candidates for these states.
MESON CORRELATION FUNCTIONS AT HIGH TEMPERATURES.
WISSEL, S.; DATTA, S.; KARSCH, F.; LAERMANN, E.; SHCHEREDIN, S.
2005-07-25
We present preliminary results for the correlation- and spectral functions of different meson channels on the lattice. The main focus lies on gaining control over cut-off as well as on the finite-volume effects. Extrapolations of screening masses above the deconfining temperature are guided by the result of the free (T = {infinity}) case on the lattice and in the continuum. We study the quenched non-perturbatively improved Wilson-clover fermion as well as the hypercube fermion action which might show less cut-off effects.
Meson Production and Baryon Resonances at CLAS
Volker Burkert
2011-02-01
I give a brief overview of the exploration of baryon properties in meson photo- and electroproduction. These processes provide ample information for the study of electromagnetic couplings of baryon resonances and to search for states, yet to be discovered. The CLAS detector, combined with the use of energy-tagged polarized photons and polarized electrons, as well as polarized targets and the measurement of recoil polarization, provide the tools for a comprehensive nucleon resonance program. I briefly present the status of this program, prospects for the next few years, and plans for the Jefferson Lab 12 GeV upgrade.
Phenomenological Implications of the Nucleon's Meson Cloud
NASA Astrophysics Data System (ADS)
Hobbs, T. J.
2015-09-01
The long-distance structure of the interacting nucleon receives important contributions from its couplings to light hadronic degrees of freedom—a light meson cloud—while an analogous nonperturbative mechanism is expected to generate an intrinsic charm (IC) component to the proton wavefunction. We investigate both possibilities, keeping for the former a special eye to improving the theoretical understanding of the pion-nucleon vertex in light of proposed measurements. Regarding the latter possibility of IC, we highlight recent results obtained by a global QCD analysis of the light-front model proposed in Hobbs et al. (Phys Rev D 89:074008, 2014).
Charmed-strange mesons revisited: Mass spectra and strong decays
NASA Astrophysics Data System (ADS)
Song, Qin-Tao; Chen, Dian-Yong; Liu, Xiang; Matsuki, Takayuki
2015-03-01
Inspired by the present experimental status of charmed-strange mesons, we perform a systematic study of the charmed-strange meson family in which we calculate the mass spectra of the charmed-strange meson family by taking a screening effect into account in the Godfrey-Isgur model and investigate the corresponding strong decays via the quark pair creation model. These phenomenological analyses of charmed-strange mesons not only shed light on the features of the observed charmed-strange states, but also provide important information on future experimental search for the missing higher radial and orbital excitations in the charmed-strange meson family, which will be a valuable task in LHCb, the forthcoming Belle II, and PANDA.
Meson mass at real and imaginary chemical potentials
NASA Astrophysics Data System (ADS)
Kashiwa, Kouji; Matsuzaki, Masayuki; Kouno, Hiroaki; Sakai, Yuji; Yahiro, Masanobu
2009-04-01
Chemical-potential dependence of pi and sigma meson masses is analyzed at both real and imaginary chemical potentials, μR and μI, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model that possesses both the extended Z3 symmetry and chiral symmetry. In the μI region, the meson masses have the Roberge-Weiss periodicity. The μI dependence of the meson masses becomes stronger as temperature increases. We argue that meson masses and physical quantities in the μR region will be determined from lattice QCD data on meson masses in the μI region by using the PNJL model, if the data are measured in the future.
Probing the perturbative dynamics of exclusive meson pair production
NASA Astrophysics Data System (ADS)
Harland-Lang, L. A.; Khoze, V. A.; Ryskin, M. G.; Stirling, W. J.
2013-10-01
We present the results of a recent novel application of the 'hard exclusive' perturbative formalism to the process gg → MMbar at large angles, where M (Mbar) is a light meson (anti-meson). As well as discussing the important theoretical features of the relevant leading-order gg → qqbar (gg) qqbar (gg) 6-parton amplitudes, we also comment on their phenomenological implications. In particular, we consider the central exclusive production of meson pairs at comparatively large transverse momentum k⊥, which is expected to proceed via this mechanism. We show that this leads to various non-trivial predictions for a range of exclusive processes, and that the cross sections for the η‧ and η mesons display significant sensitivity to any valence gg component of the meson wavefunctions.
Meson mass at real and imaginary chemical potentials
Kashiwa, Kouji; Sakai, Yuji; Yahiro, Masanobu; Matsuzaki, Masayuki; Kouno, Hiroaki
2009-04-01
Chemical-potential dependence of pi and sigma meson masses is analyzed at both real and imaginary chemical potentials, {mu}{sub R} and {mu}{sub I}, by using the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) model that possesses both the extended Z{sub 3} symmetry and chiral symmetry. In the {mu}{sub I} region, the meson masses have the Roberge-Weiss periodicity. The {mu}{sub I} dependence of the meson masses becomes stronger as temperature increases. We argue that meson masses and physical quantities in the {mu}{sub R} region will be determined from lattice QCD data on meson masses in the {mu}{sub I} region by using the PNJL model, if the data are measured in the future.
QCD description of backward vector meson hard electroproduction
NASA Astrophysics Data System (ADS)
Pire, B.; Semenov-Tian-Shansky, K.; Szymanowski, L.
2015-05-01
We consider backward vector meson exclusive electroproduction off nucleons in the framework of collinear QCD factorization. Nucleon to vector meson transition distribution amplitudes (TDAs) arise as building blocks for the corresponding factorized amplitudes. In the near-backward kinematics, the suggested factorization mechanism results in the dominance of the transverse cross section of vector meson production (σT≫σL ) and in the characteristic 1 /Q8-scaling behavior of the cross section. We evaluate nucleon to vector meson TDAs in the cross-channel nucleon exchange model and present estimates of the differential cross section for backward ρ0, ω and ϕ meson production off protons. The resulting cross sections are shown to be measurable in the forthcoming JLab@12 GeV experiments.
Charmed Mesons in Nuclei with Heavy-Quark Spin Symmetry
NASA Astrophysics Data System (ADS)
Tolos, L.; Garcia-Recio, C.; Nieves, J.; Romanets, O.; Salcedo, L. L.
2013-08-01
We study the properties of charmed pseudoscalar and vector mesons in dense matter within a unitary meson-baryon coupled-channel model which incorporates heavy-quark spin symmetry. This is accomplished by extending the SU(3) Weinberg-Tomozawa Lagrangian to incorporate spin-flavor symmetry and implement a suitable flavor symmetry breaking. Several resonances with negative parity are generated dynamically by the s-wave interaction between pseudoscalar and vector meson multiplets with 1/2+ and 3/2+ baryons. Those states are then compared to experimental data as well as theoretical models. Next, Pauli-blocking effects and meson self-energies are introduced in a self-consistent manner to obtain the open-charm meson spectral functions in a dense nuclear environment. We finally discuss the formation of D-mesic nuclei.
Sharma, Neelesh; Verma, R. C.
2010-11-01
Two-body hadronic weak decays of B{sub c} meson emitting pseudoscalar and heavy scalar mesons are investigated using the Spectator Quark Model. Decay amplitudes are obtained using the factorization scheme; consequently, branching ratios are predicted in the Isgur-Scora-Grinstein-Wise (ISGW II) model.
Weak Decays of Excited B Mesons.
Grinstein, B; Martin Camalich, J
2016-04-01
We investigate the decays of the excited (bq[over ¯]) mesons as probes of the short-distance structure of the weak ΔB=1 transitions. These states are unstable under the electromagnetic or strong interactions, although their widths are typically suppressed by phase space. Compared to the pseudoscalar B meson, the purely leptonic decays of the vector B^{*} are not chirally suppressed and are sensitive to different combinations of the underlying weak effective operators. An interesting example is B_{s}^{*}→ℓ^{+}ℓ^{-}, which has a rate that can be accurately predicted in the standard model. The branching fraction is B∼10^{-11}, irrespective of the lepton flavor and where the main uncertainty stems from the unmeasured and theoretically not well known B_{s}^{*} width. We discuss the prospects for producing this decay mode at the LHC and explore the possibility of measuring the B_{s}^{*}→ℓℓ amplitude, instead, through scattering experiments at the B_{s}^{*} resonance peak. PMID:27104698
NASA Astrophysics Data System (ADS)
Papandreou, Zisis
2006-02-01
A study of several rare η decays near threshold was carried out at the C-6 (π-) beamline of the Alternating Gradient Synchrotron at Brookhaven National Laboratory with the Crystal Ball detector, an electromagnetic calorimeter with nearly 4π geometric acceptance that is comprised of 672 optically isolated NaI(Tl) crystals with a thickness of 15.7 radiation lengths. Results from the search for the CP forbidden decay η → 4π0 and the investigation of the quadratic slope parameter in η → 3π0 decay will be profiled, among others. The focus of the talk will be on the η → π0γγ rare decay: its relative branching ratio was extracted to be B1 = (8.3 ± 2.8 ± 1.2) × 10-4, based on the analysis of 3 × 107 detected η mesons. This leads to a partial width for the eta meson of Γ(η → π0γγ) = (0.32 ± 0.15) eV/c2, a value much lower than past measurements and in line with Chiral Perturbation Theory calculations.
Meson Electro-/Photo-Production from QCD
NASA Astrophysics Data System (ADS)
Briceño, Raúl A.
2016-07-01
Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and Δ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of Q^2 > 1.5 GeV^2 . In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.
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.
NASA Technical Reports Server (NTRS)
Takahashi, Y.; Eby, P. B.
1985-01-01
Possibilities of observing abundances of phi mesons and narrow hadronic pairs, as results of QGP and Chiral transitions, are considered for nucleus-nucleus interactions. Kinematical requirements in forming close pairs are satisfied in K+K decays of S(975) and delta (980) mesons with small phi, and phi (91020) mesons with large PT, and in pi-pi decays of familiar resonance mesons only in a partially restored chiral symmetry. Gluon-gluon dominance in QGP can enhance phi meson production. High hadronization rates of primordial resonance mesons which form narrow hadronic pairs are not implausible. Past cosmic ray evidences of anomalous phi production and narrow pair abundances are considered.
Interaction of eta mesons with nuclei.
Kelkar, N G; Khemchandani, K P; Upadhyay, N J; Jain, B K
2013-06-01
Back in the mid-1980s, a new branch of investigation related to the interaction of eta mesons with nuclei came into existence. It started with the theoretical prediction of possible exotic states of eta mesons and nuclei bound by the strong interaction and later developed into an extensive experimental program to search for such unstable states as well as understand the underlying interaction via eta-meson producing reactions. The vast literature of experimental as well as theoretical works that studied various aspects of eta-producing reactions such as the π(+)n → ηp, pd → (3)Heη, p (6)Li → (7)Be η and γ (3)He → η X, to name a few, had but one objective in mind: to understand the eta-nucleon (ηN) and hence the η-nucleus interaction which could explain the production data and confirm the existence of some η-mesic nuclei. In spite of these efforts, there remain uncertainties in the knowledge of the ηN and hence the η-nucleus interaction. Therefore, this review is an attempt to bind together the findings in these works and draw some global and specific conclusions which can be useful for future explorations.The ηN scattering length (which represents the strength of the η-nucleon interaction) using different theoretical models and analyzing the data on η production in pion, photon and proton induced reactions was found to be spread out in a wide range, namely, 0.18 ≤ Re aηN ≤ 1.03 fm and 0.16 ≤ Rm aηN ≤ 0.49 fm. Theoretical searches of heavy η-mesic nuclei based on η-nucleus optical potentials and lighter ones based on Faddeev type few-body approaches predict the existence of several quasibound and resonant states. Although some hints of η-mesic states such as (3)(η)He and (25)(η)Mg do exist from previous experiments, the promise of clearer signals for the existence of η-mesic nuclei lies in the experiments to be performed at the J-PARC, MAMI and COSY facilities in the near future. This review is aimed at giving an overall status
Interaction of eta mesons with nuclei
NASA Astrophysics Data System (ADS)
Kelkar, N. G.; Khemchandani, K. P.; Upadhyay, N. J.; Jain, B. K.
2013-06-01
Back in the mid-1980s, a new branch of investigation related to the interaction of eta mesons with nuclei came into existence. It started with the theoretical prediction of possible exotic states of eta mesons and nuclei bound by the strong interaction and later developed into an extensive experimental program to search for such unstable states as well as understand the underlying interaction via eta-meson producing reactions. The vast literature of experimental as well as theoretical works that studied various aspects of eta-producing reactions such as the π+n → ηp, pd → 3Heη, p 6Li → 7Be η and γ 3He → η X, to name a few, had but one objective in mind: to understand the eta-nucleon (ηN) and hence the η-nucleus interaction which could explain the production data and confirm the existence of some η-mesic nuclei. In spite of these efforts, there remain uncertainties in the knowledge of the ηN and hence the η-nucleus interaction. Therefore, this review is an attempt to bind together the findings in these works and draw some global and specific conclusions which can be useful for future explorations. The ηN scattering length (which represents the strength of the η-nucleon interaction) using different theoretical models and analyzing the data on η production in pion, photon and proton induced reactions was found to be spread out in a wide range, namely, 0.18 ⩽ ℜe aηN ⩽ 1.03 fm and 0.16 ⩽ ℑm aηN ⩽ 0.49 fm. Theoretical searches of heavy η-mesic nuclei based on η-nucleus optical potentials and lighter ones based on Faddeev type few-body approaches predict the existence of several quasibound and resonant states. Although some hints of η-mesic states such as ^3_{\\eta} He and ^{25}_{\\eta} Mg do exist from previous experiments, the promise of clearer signals for the existence of η-mesic nuclei lies in the experiments to be performed at the J-PARC, MAMI and COSY facilities in the near future. This review is aimed at giving an overall
Absorption of the omega and phi Mesons in Nuclei
M. H. Wood, R. Nasseripour, M. Paolone, C. Djalali, D. P. Weygand, the CLAS Collaboration
2010-09-01
Due to their long lifetimes, the $\\omega$ and $\\phi$ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from $^{2}$H, C, Ti, Fe, and Pb targets. This paper reports the first measurement of the ratio of nuclear transparencies for the $e^{+}e^{-}$ channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels.
Light meson decays from photon-induced reactions with CLAS
NASA Astrophysics Data System (ADS)
Kunkel, Michael C.
2016-05-01
Photo-production experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Laboratory produce data sets with unprecedented statistics for light mesons. With these data sets, measurements of transition form factors for η, ω, and η' mesons via conversion decays can be performed using the invariant mass distribution of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference can be performed using a Dalitz plot analysis of the meson decay. An overview of the first results, from existing CLAS data, and future prospects within the newly upgraded CLAS12 apparatus are given.
Cross sections for inelastic meson-meson scattering via quark-antiquark annihilation
NASA Astrophysics Data System (ADS)
Shen, Zhen-Yu; Xu, Xiao-Ming; Weber, H. J.
2016-08-01
We study inelastic meson-meson scattering that is governed by quark-antiquark annihilation and creation involving a quark and an antiquark annihilating into a gluon, and subsequently the gluon creating another quark-antiquark pair. The resultant hadronic reactions include for I =1 : π π →ρ ρ , K K ¯→K*K¯*, K K¯*→K*K¯*, K*K ¯→K*K¯*, as well as π π →K K ¯, π ρ →K K¯*, π ρ →K*K ¯, and K K ¯→ρ ρ . In each reaction, one or two Feynman diagrams are involved in the Born approximation. We derive formulas for the unpolarized cross section, the transition amplitude, and the transition potential for quark-antiquark annihilation and creation. The unpolarized cross sections for the reactions are calculated at six temperatures, and prominent temperature dependence is found. It is due to differences among mesonic temperature dependence in hadronic matter.
Meson photoproduction from the nucleon at CLAS
Daniel P. Watts
2012-01-01
The excitation spectrum of the nucleon provides a stringent constraint on the dynamics and interactions of its internal constituents and therefore probes the mechanism of confinement in the light quark sector. Our detailed knowlege of this excitation spectrum is poor, with many predicted states not yet observed in experiment and many 'established' states having poorly known properties. To address these shortcomings a worldwide effort is currently underway exploiting the latest generation of electron and photon beams in detailed studies of meson photoproduction from nucleon targets. A major contribution to this effort will come from the experimental programme at Jefferson Lab exploiting the frozen spin target (FROST) with the CLAS spectrometer. The status of this project will be presented along with preliminary results and analyses.
Meson Spectroscopy At Jlab At 12 Gev
Fegan, Stuart
2014-12-01
The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.
Nonleptonic weak decays of charmed mesons
NASA Astrophysics Data System (ADS)
Buccella, F.; Lusignoli, M.; Miele, G.; Pugliese, A.; Santorelli, P.
1995-04-01
A previous analysis of two-body Cabibbo-allowed nonleptonic decays of D0 mesons and of Cabibbo-allowed and first-forbidden decays of D+ and D+s has been adjourned using more recent experimental data and extended to the Cabibbo-forbidden decays of D0. Annihilation and W-exchange contributions as well as final state interaction effects (assumed to be dominated by nearby resonances) have been included and are in fact crucial to obtain a reasonable agreement with the experimental data, which show large flavor SU(3) violations. New fitting parameters are necessary to describe rescattering effects for Cabibbo-forbidden D0 decays, given the lack of experimental information on isoscalar resonances. We keep their number to a minimum, three, using phenomenologically based considerations. We also discuss CP-violating asymmetries.
Model discrimination in pseudoscalar-meson photoproduction
NASA Astrophysics Data System (ADS)
Nys, J.; Ryckebusch, J.; Ireland, D. G.; Glazier, D. I.
2016-08-01
To learn about a physical system of interest, experimental results must be able to discriminate among models. We introduce a geometrical measure to quantify the distance between models for pseudoscalar-meson photoproduction in amplitude space. Experimental observables, with finite precision, map to probability distributions in amplitude space, and the characteristic width scale of such distributions needs to be smaller than the distance between models if the observable data are going to be useful. We therefore also introduce a method for evaluating probability distributions in amplitude space that arise as a result of one or more measurements, and show how one can use this to determine what further measurements are going to be necessary to be able to discriminate among models.
Photoproduction of scalar mesons at CLAS
NASA Astrophysics Data System (ADS)
Chandavar, Shloka; Hicks, Kenneth; Weygand, Dennis; CLAS Collaboration
2013-10-01
A single gluon, which carries color charge, cannot exist independently outside a hadron. Lattice QCD calculations in pure SU(3), however, predict the existence of glueballs which are bound states of two or more gluons. In the real world, the challenge to identify glueballs experimentally is the fact they mix with meson states. The f0 (1500) is one of several candidates for the lightest glueball, with JPC =0++ . We investigate the presence of this particle in photoproduction by analyzing the reaction γp -->fJ p -->KS0KS0 p --> 2 (π+π-) p . This reaction was studied using data from the g12 experiment performed using the CLAS detector at Jefferson Lab. A preliminary partial wave analysis, performed on the KS0KS0 invariant mass spectrum, will be presented. These results update those presented for this reaction channel at previous conferences. This work is supported by grant from NSF.
Production of charmed mesons in Z decays
NASA Astrophysics Data System (ADS)
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Pietrzyk, B.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Marinelli, N.; Natali, S.; Nuzzo, S.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhang, L.; Zhao, W.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Girone, M.; Hagelberg, R.; Harvey, J.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Maggi, M.; Markou, C.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Pater, J. R.; Perlas, J. A.; Perrodo, P.; Pusztaszeri, J.-F.; Ranjard, F.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Tomalin, I. R.; Veenhof, R.; Wachsmuth, H.; Wasserbaech, S.; Wiedemann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Bardadin-Otwinowska, M.; Barres, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Saadi, F.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Johnson, S. D.; Møllerud, R.; Nilsson, B. S.; Kyriakis, A.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, B.; Fouque, G.; Passalacqua, L.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Focardi, E.; Moneta, L.; Parrini, G.; Corden, M.; Delfino, M.; Georgiopoulos, C.; Ikeda, M.; Jaffe, D. E.; Levinthal, D.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Pepe=Altarelli, M.; Salomone, S.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Thorn, S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Graefe, G.; Hanke, P.; Hepp, V.; Karger, C.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Beuselinck, M.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Hassard, J. F.; Lieske, N. M.; Moutoussi, A.; Nash, J.; Patton, S.; Payne, D. G.; Phillips, M. J.; San Martin, G.; Sedgbeer, J. K.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Vogl, R.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttal, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Walther, S. M.; Wanke, R.; Wolf, B.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Calvet, D.; Carr, J.; Coyle, P.; Diaconu, C.; Drinkard, J.; Etienne, F.; Nicod, D.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Jakobs, K.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, G.; Richter, R.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, H.; Stiegler, U.; Denis, R. St.; Wolf, G.; Alemany, R.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Musolino, G.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Luisiani, A.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Valassi, A.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Gao, Y.; Green, M. G.; Johnson, D. L.; March, P. V.; Medcalf, T.; Mir, Ll. M.; Quazi, I. S.; Strong, J. A.; Bertin, V.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Edwards, M.; Norton, P. R.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Babbage, W.; Booth, C. N.; Buttar, C.; Cartwright, S.; Combley, F.; Dawson, I.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Smolik, L.; Bosisio, L.; Della Marina, R.; Giannini, G.; Bobbo, B.; Pitis, L.; Ragusa, F.; Bellantoni, L.; Chen, W.; Conway, J. S.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Hayes, O. J.; Nachtman, J. M.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I.; Sharma, V.; Shi, Z. H.; Turk, J. D.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.
1994-03-01
The production of charmed mesonsmathop {D^0 }limits^{( - )} , D ± , and D *± is studied in a sample of 478,000 hadronic Z decays. The production rates are measured to be 10052_2005_Article_BF01559519_TeX2GIFE1.gif begin{gathered} {Γ (Z to D^{* ± } X)}/{Γ _{had }} = 0.187 ± 0.015(exp .) ± 0.013(BR), \\ {Γ (Z to D^ ± X)}/{Γ _{had }} = 0.251 ± 0.026(exp .) ± 0.025(BR), \\ {Γ (Z to mathop {D^0 }limits^{( - )} X)}/{Γ _{had }} = 0.518 ± 0.052(exp .) ± 0.035(BR), \\ where the errors from this analysis are separated from those coming from the D branching ratios (BR). The D *± momentum distribution is extracted separately forZ to cbar c andZ to bbar b events with the help of event shape variables. It is consistent with the prediction of the JETSET Monte Carlo program after adjustment of the charm fragmentation function. Constraining the shape of theZ to bbar b contribution, the average fraction of the beam energy taken by a D * meson produced in the fragmentation of a charm quark is extracted by a parametric fit to be < X E > c =0.495±0.011±0.007. Evidence for D **0 ( D 1(2420)0 and/or D {2/*}(2460)0) production is found in theD^{* ± } π ^ mp channel, accounting for a fraction (18±5±2)% of all D *± production. The relative production of vector and pseudoscalar mesons is dicussed, together with the possible effects of D ** production. The c-quark forward-backward Z-pole asymmetry is detrmined from that of high momentum D *± to be A {/FB 0,c }=(7.7±4.4)%.
Improved measurement of the B 0 and B + meson lifetimes
NASA Astrophysics Data System (ADS)
Buskulic, D.; de Bonis, I.; Decamp, D.; Ghez, P.; Goy, C.; Lees, J. P.; Lucotte, A.; Minard, M. N.; Odier, P.; Pietrzyk, B.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Delfino, M.; Efthymiopoulos, I.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Juste, A.; Martinez, M.; Orteu, S.; Pacheco, A.; Padilla, C.; Pascual, A.; Perlas, J. A.; Riu, I.; Sanchez, F.; Teubert, F.; Colaleo, A.; Creanza, D.; de Palma, M.; Gelao, G.; Girone, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Marinelli, N.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Alemany, R.; Bazarko, A. O.; Bonvicini, G.; Cattaneo, M.; Comas, P.; Coyle, P.; Drevermann, H.; Forty, R. W.; Frank, M.; Hagelberg, R.; Harvey, J.; Janot, P.; Jost, B.; Kneringer, E.; Knobloch, J.; Lehraus, I.; Martin, E. B.; Mato, P.; Minten, A.; Miquel, R.; Mir, Ll. M.; Moneta, L.; Oest, T.; Palla, F.; Pater, J. R.; Pusztaszeri, J. F.; Ranjard, F.; Rensing, P.; Rolandi, L.; Schlatter, D.; Schmelling, M.; Schneider, O.; Tejessy, W.; Tomalin, I. R.; Venturi, A.; Wachsmuth, H.; Wagner, A.; Wildish, T.; Ajaltouni, Z.; Barrès, A.; Boyer, C.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Rossignol, J. M.; Fearnley, T.; Hansen, J. B.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Nilsson, B. S.; Wäänänen, A.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Siotis, I.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Bourdon, P.; Rougé, A.; Rumpf, M.; Valassi, A.; Verderi, M.; Videau, H.; Candlin, D. J.; Parsons, M. I.; Focardi, E.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Jaffe, D. E.; Antonelli, A.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Casper, D.; Chiarella, V.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Curtis, L.; Dorris, S. J.; Halley, A. W.; Knowles, I. G.; Lynch, J. G.; O'Shea, V.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Thomson, F.; Thorn, S.; Turnbull, R. M.; Becker, U.; Geweniger, C.; Graefe, G.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E. E.; Putzer, A.; Rensch, B.; Schmidt, M.; Sommer, J.; Stenzel, H.; Tittel, K.; Werner, S.; Wunsch, M.; Abbaneo, D.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Dornan, P. J.; Moutoussi, A.; Nash, J.; Sedgbeer, J. K.; Stacey, A. M.; Williams, M. D.; Dissertori, G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Betteridge, A. P.; Bowdery, C. K.; Colrain, P.; Crawford, G.; Finch, A. J.; Foster, F.; Hughes, G.; Sloan, T.; Williams, M. I.; Galla, A.; Greene, A. M.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H. G.; van Gemmeren, P.; Zeitnitz, C.; Aubert, J. J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Bujosa, G.; Calvet, D.; Carr, J.; Diaconu, C.; Etienne, F.; Konstantinidis, N.; Payre, P.; Rousseau, D.; Talby, M.; Sadouki, A.; Thulasidas, M.; Trabelsi, K.; Aleppo, M.; Ragusa, F.; Abt, I.; Assmann, R.; Bauer, C.; Blum, W.; Dietl, H.; Dydak, F.; Ganis, G.; Gotzhein, C.; Jakobs, K.; Kroha, H.; Lütjens, G.; Lutz, G.; Männer, W.; Moser, H. G.; Richter, R.; Rosado-Schlosser, A.; Schael, S.; Settles, R.; Seywerd, H.; St. Denis, R.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J. F.; Heusse, Ph.; Jacquet, M.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A. M.; Nikolic, I.; Park, H. J.; Park, I. C.; Schune, M. H.; Simion, S.; Veillet, J. J.; Videau, I.; Azzurri, P.; Bagliesi, G.; Batignani, G.; Bettarini, S.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Ciulli, V.; Dell'Orso, R.; Fantechi, R.; Ferrante, I.; Foà, L.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Lusiani, A.; Marrocchesi, P. S.; Messineo, A.; Rizzo, G.; Sanguinetti, G.; Sciabà, A.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Vannini, C.; Verdini, P. G.; Walsh, J.; Blair, G. A.; Bryant, L. M.; Cerutti, F.; Chambers, J. T.; Gao, Y.; Green, M. G.; Medcalf, T.; Perrodo, P.; Strong, J. A.; von Wimmersperg-Toeller, J. H.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Haywood, S.; Maley, P.; Norton, P. R.; Thompson, J. C.; Wright, A. E.; Bloch-Devaux, B.; Colas, P.; Emery, S.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Marx, B.; Perez, P.; Rander, J.; Renardy, J. F.; Roussarie, A.; Schuller, J. P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Black, S. N.; Dann, J. H.; Johnson, R. P.; Kim, H. Y.; Litke, A. M.; McNeil, M. A.; Taylor, G.; Booth, C. N.; Boswell, R.; Brew, C. A. J.; Cartwright, S.; Combley, F.; Koksal, A.; Letho, M.; Newton, W. M.; Reeve, J.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Büscher, V.; Cowan, G.; Grupen, C.; Lutters, G.; Minguet-Rodriguez, J.; Rivera, F.; Saraiva, P.; Smolik, L.; Stephan, F.; Apollonio, M.; Bosisio, L.; Della Marina, R.; Giannini, G.; Gobbo, B.; Musolino, G.; Rothberg, J.; Wasserbaech, S.; Armstrong, S. R.; Bellantoni, L.; Elmer, P.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; González, S.; Grahl, J.; Greening, T. C.; Harton, J. L.; Hayes, O. J.; Hu, H.; McNamara, P. A.; Nachtman, J. M.; Orejudos, W.; Pan, Y. B.; Saadi, Y.; Schmitt, M.; Scott, I. J.; Sharma, V.; Walsh, A. M.; Wu, Sau Lan; Wu, X.; Yamartino, J. M.; Zheng, M.; Zobernig, G.
1996-03-01
The lifetimes of the B 0 and B + mesons have been measured with the Aleph detector at LEP, using approximately 3 million hadronic Z decays collected in the period 1991 1994. In the first of three methods, semileptonic decays of B 0 and B + mesons were partially reconstructed by identifying events containing a lepton with an associated D*- orbar D^0 meson. The second method used fully reconstructed B 0 and B + mesons. The third method, used to measure the B 0 lifetime, employed a partial reconstruction technique to identify B 0→ D*- π + X decays. The combined results are begin{gathered} tau _0 = 1.55 ± 0.06 ± 0.03 ps, \\ tau _ + = 1.58 ± 0.09 ± 0.03 ps, \\ tfrac{{tau _ + }}{{tau _0 }} = 1.03 ± 0.08 ± 0.02. \\ .
Search for medium modification of the $\\rho$ meson
R. Nasseripour; M. H. Wood; C. Djalali; D. P. Weygand; C. Tur; U. Mosel; P. Muehlich; CLAS Collaboration
2007-08-01
The photoproduction of vector mesons on various nuclei has been studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. The vector mesons, $\\rho$, $\\omega$, and $\\phi$, are observed via their decay to $e^+e^-$, in order to reduce the effects of final state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the $\\rho$ meson. The $\\rho$ spectral function is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no significant mass shift for the $\\rho$ meson; however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.
Absorption of the {omega} and {phi} Mesons in Nuclei
Wood, M. H.; Nasseripour, R.; Berman, B. L.; Briscoe, W. J.; Munevar, E.; Strakovsky, I. I.; Paolone, M.; Djalali, C.; Gothe, R. W.; Graham, L.; Tedeschi, D. J.; Tkachenko, S.; Zhao, Z. W.; Weygand, D. P.; Batourine, V.; Burkert, V. D.; Carman, D. S.; Deur, A.; Guo, L.; Nadel-Turonski, P.
2010-09-10
Because of their long lifetimes, the {omega} and {phi} mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from {sup 2}H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e{sup +}e{sup -} channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the {omega} meson is stronger than that reported by the CBELSA-TAPS experiment and cannot be explained by recent theoretical models.
Toward the excited isoscalar meson spectrum from lattice QCD
Dudek, Jozef J.; Edwards, Robert G.; Guo, Peng; Thomas, Christopher E.
2013-11-18
We report on the extraction of an excited spectrum of isoscalar mesons using lattice QCD. Calculations on several lattice volumes are performed with a range of light quark masses corresponding to pion masses down to about ~400 MeV. The distillation method enables us to evaluate the required disconnected contributions with high statistical precision for a large number of meson interpolating fields. We find relatively little mixing between light and strange in most J^{PC} channels; one notable exception is the pseudoscalar sector where the approximate SU(3)_{F} octet, singlet structure of the η, η' is reproduced. We extract exotic J^{PC} states, identified as hybrid mesons in which an excited gluonic field is coupled to a color-octet qqbar pair, along with non-exotic hybrid mesons embedded in a qq¯-like spectrum.
Toward the excited isoscalar meson spectrum from lattice QCD
Dudek, Jozef J.; Edwards, Robert G.; Guo, Peng; Thomas, Christopher E.
2013-11-18
We report on the extraction of an excited spectrum of isoscalar mesons using lattice QCD. Calculations on several lattice volumes are performed with a range of light quark masses corresponding to pion masses down to about ~400 MeV. The distillation method enables us to evaluate the required disconnected contributions with high statistical precision for a large number of meson interpolating fields. We find relatively little mixing between light and strange in most JPC channels; one notable exception is the pseudoscalar sector where the approximate SU(3)F octet, singlet structure of the η, η' is reproduced. We extract exotic JPC states, identifiedmore » as hybrid mesons in which an excited gluonic field is coupled to a color-octet qqbar pair, along with non-exotic hybrid mesons embedded in a qq¯-like spectrum.« less
Analysis tools for MesonEx at CLAS12
NASA Astrophysics Data System (ADS)
Glazier, D. I.
2016-05-01
The JLAB upgrade will soon be completed and the new CLAS12 detector system will collect large volumes of data allowing detailed investigations of many aspects of hadron physics. The focus of the MesonEx experiment is on the production of mesonic states by low Q2 virtual photons, or quasi-real photons. Studying such mesonic states is a particularly challenging data analysis problem, requiring well understood detector systems, clean signal and background separation, handling of large volumes of data and crucially a close collaboration between experimentalists and theorists to ensure the most sophisticated theoretical methods are used to interrogate the data. Here we briefly outline some of the analysis and methods that are being used to prepare for the MesonEx experiment.
Light Meson Decays from Photon-Induced Reactions with CLAS
NASA Astrophysics Data System (ADS)
Kunkel, Michael; CLAS Collaboration; Light Meson Decay (LMD) Team
2015-04-01
Photo-production experiments with the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Laboratory produce data sets with unprecedented statistics of light mesons. With these data sets, measurements of transition form factors for η, ω, and η ' via conversion decays can be performed using a line shape analysis on the invariant mass of the final state dileptons. Tests of fundamental symmetries and information on the light quark mass difference can be performed using a Dalitz plot analysis of the meson decay. In addition, the data allows for a search for dark matter, such as the heavy photon via conversion decays of light mesons and physics beyond the Standard Model can be searched for via invisible decays of η mesons. An overview of the first results and future prospects will be given.
Selection rules for hadronic transitions of XYZ mesons.
Braaten, Eric; Langmack, Christian; Smith, D Hudson
2014-06-01
Many of the XYZ mesons discovered in the last decade can be identified as bound states of a heavy quark and antiquark in Born-Oppenheimer (BO) potentials defined by the energy of gluon and light-quark fields in the presence of static color sources. The mesons include quarkonium hybrids, which are bound states in excited flavor-singlet BO potentials, and quarkonium tetraquarks, which are bound states in BO potentials with light-quark+antiquark flavor. The deepest hybrid potentials are known from lattice QCD calculations. The deepest tetraquark potentials can be inferred from lattice QCD calculations of static adjoint mesons. Selection rules for hadronic transitions are derived and used to identify XYZ mesons that are candidates for ground-state energy levels in the BO potentials for charmonium hybrids and tetraquarks. PMID:24949759
Semileptonic B and Bs decays into orbitally excited charmed mesons
NASA Astrophysics Data System (ADS)
Segovia, J.; Albertus, C.; Entem, D. R.; Fernández, F.; Hernández, E.; Pérez-García, M. A.
2011-11-01
The BABAR Collaboration has recently reported products of branching fractions that include B meson semileptonic decays into final states with charged and neutral D1(2420) and D2*(2460), two narrow orbitally excited charmed mesons. We evaluate these branching fractions, together with those concerning D0*(2400) and D1'(2430) mesons, within the framework of a constituent quark model. The calculation is performed in two steps, one of which involves a semileptonic decay and the other is mediated by a strong process. Our results are in agreement with the experimental data. We also extend the study to semileptonic decays of Bs into orbitally excited charmed-strange mesons, providing predictions to the possible measurements to be carried out at LHC.
SEARCH FOR IN-MEDIUM MODIFICATIONS OF THE ρ MESON
WEYGAND, D P; DJALALI, C; NASSERIPOUR, R; WOOD, M
2007-01-01
The photoproduction of vector mesons on various nuclei has been studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory, and here we present preliminary results. All three vector mesons, ρ, ω,and φ, are observed via their decay to e^{+}e^{-}, in order to reduce the effects of final state interactions in the nucleus. Of particular interest is possible in-medium effects on the properties of the ρ meson. The ρ spectral function is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no effects on the mass of the ρ meson, however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.
Nuclear photoproduction of vector mesons within a Monte Carlo approach
NASA Astrophysics Data System (ADS)
González, I.; Guzmán, F.; Deppman, A.
2014-05-01
We present recent improvements in the crisp code for nuclear reaction simulation. The photoproduction of vector mesons was included in the code, which can evaluate also final state interaction of these mesons with the nucleus. Effects such as shadowing, subthreshold production, and Pauli blocking can be observed. The model is described in detail and some important quantities, such as cross section and nuclear transparency, are calculated as examples of the potential of our code.
Eta Meson Production in Proton-Proton and Nuclear Collisions
NASA Technical Reports Server (NTRS)
Norbury, John W.; Dick, Frank
2008-01-01
Total cross sections for eta meson production in proton - proton collisions are calculated. The eta meson is mainly produced via decay of the excited nucleon resonance at 1535 MeV. A scalar quantum field theory is used to calculate cross sections, which also include resonance decay. Comparison between theory and experiment is problematic near threshold when resonance decay is not included. When the decay is included, the comparison between theory and experiment is much better.
Using anti pp annihilation to find exotic mesons
Sharpe, S.R.
1987-10-01
Present data suggests that a number of mesons have been found which cannot be accommodated in standard anti qq multiplets. Theory suggests that such exotic mesons should exist in the spectrum of Quantum Chromodynamics, but provides little guide to their properties. It is argued that a high luminosity, low energy anti pp machine would be a powerful tool with which to search for such exotics.
Neutrino Production of Mesons in the Generalized Parton Picture
NASA Astrophysics Data System (ADS)
McAskill, Tracy
The handbag model and its usefulness in generating cross sections for light pseudoscalar mesons is investigated here. The soft part of the handbag model is first parametrized to fit well-known models of generalized parton distributions (GPD's), then cross sections are calculated directly from the GPD's. This is then directly extended to the calculation of neutrino cross sections for the production of the same type of light mesons.
Highly excited and exotic meson spectroscopy from lattice QCD
Christopher Thomas
2011-05-01
I will discuss recent progress in extracting highly excited and exotic meson spectra using lattice QCD. New results in the light meson sector will be presented, where a combination of techniques have enabled us to confidently identify the spin of extracted states. Highlights include many states with exotic quantum numbers and, for the first time in a lattice QCD calculation, spin-four states. I will conclude with comments on future prospects.
Coupling vector and pseudoscalar mesons to study baryon resonances
Khemchandani, K. P.; Kaneko, H.; Hosaka, A.; Martinez Torres, A.; Nagahiro, H.
2011-11-01
A study of meson-baryon systems with total strangeness -1 is made within a framework based on the chiral and hidden local symmetries. These systems consist of octet baryons, pseudoscalar and vector mesons. The pseudoscalar meson-baryon (PB) dynamics has been earlier found determinant for the existence of some strangeness -1 resonances, for example, {Lambda}(1405), {Lambda}(1670), etc. The motivation of the present work is to study the effect of coupling the closed vector meson-baryon (VB) channels to these resonances. To do this, we obtain the PB{yields}PB and VB{yields}VB amplitudes from the t-channel diagrams and the PB{r_reversible}VB amplitudes are calculated using the Kroll-Ruddermann term where, considering the vector meson dominance phenomena, the photon is replaced by a vector meson. The calculations done within this formalism reveal a very strong coupling of the VB channels to the {Lambda}(1405) and {Lambda}(1670). In the isospin 1 case, we find evidence for a double pole structure of the {Sigma}(1480) which, like the isospin 0 resonances, is also found to couple strongly to the VB channels. The strong coupling of these low-lying resonances to the VB channels can have important implications on certain reactions producing them.
Medium Modification of the Light Vector Mesons in Nuclei
Nasseripour, R.; Djalali, C.; Wood, M.; Weygand, D.
2008-10-13
Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the {rho} vector mesons were investigated via their rare leptonic decay to e+e{sup -}. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The {rho} meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the rho meson in the nuclear medium rule out large medium effects. Transparency studies of the {omega} and {phi} vector mesons allows a determination of their widths in the medium.
Effects of δ mesons in relativistic mean field theory
NASA Astrophysics Data System (ADS)
Singh, Shailesh K.; Biswal, S. K.; Bhuyan, M.; Patra, S. K.
2014-04-01
The effect of δ- and ω-ρ-meson cross couplings on asymmetry nuclear systems are analyzed in the framework of an effective field theory motivated relativistic mean field formalism. The calculations are done on top of the G2 parameter set, where these contributions are absent. To show the effect of δ meson on the nuclear system, we split the isospin coupling into two parts: (i) gρ due to ρ meson and (ii) gδ for δ meson. Thus, our investigation is based on varying the coupling strengths of the δ and ρ mesons to reproduce the binding energies of the nuclei Ca48 and Pb208. We calculate the root mean square radius, binding energy, single particle energy, density, and spin-orbit interaction potential for some selected nuclei and evaluate the Lsym and Esym coefficients for nuclear matter as function of δ- and ω-ρ-meson coupling strengths. As expected, the influence of these effects are negligible for the symmetric nuclear system, but substantial for the contribution with large isospin asymmetry.
Mesons in strong magnetic fields: (I) General analyses
NASA Astrophysics Data System (ADS)
Hattori, Koichi; Kojo, Toru; Su, Nan
2016-07-01
We study properties of neutral and charged mesons in strong magnetic fields | eB | ≫ ΛQCD2 with ΛQCD being the QCD renormalization scale. Assuming long-range interactions, we examine magnetic-field dependences of various quantities such as the constituent quark mass, chiral condensate, meson spectra, and meson wavefunctions by analyzing the Schwinger-Dyson and Bethe-Salpeter equations. Based on the density of states obtained from these analyses, we extend the hadron resonance gas (HRG) model to investigate thermodynamics at large B. As B increases the meson energy behaves as a slowly growing function of the meson's transverse momenta, and thus a large number of meson states is accommodated in the low energy domain; the density of states at low temperature is proportional to B2. This extended transverse phase space in the infrared regime significantly enhances the HRG pressure at finite temperature, so that the system reaches the percolation or chiral restoration regime at lower temperature compared to the case without a magnetic field; this simple picture would offer a gauge invariant and intuitive explanation of the inverse magnetic catalysis.
Properties of mesons in a strong magnetic field
NASA Astrophysics Data System (ADS)
Zhang, Rui; Fu, Wei-jie; Liu, Yu-xin
2016-06-01
By extending the Φ -derivable approach in the Nambu-Jona-Lasinio model to a finite magnetic field we calculate the properties of pion, σ , and ρ mesons in a magnetic field at finite temperature not only in the quark-antiquark bound state scheme but also in the pion-pion scattering resonant state scenario. Our calculation as a result makes manifest that the masses of π 0 and σ meson can be nearly degenerate at the pseudo-critical temperature which increases with increasing magnetic field strength, and the π ^{± } mass ascends suddenly at almost the same critical temperature. Meanwhile the ρ mesons' masses decrease with the temperature but increase with the magnetic field strength. We also check the Gell-Mann-Oakes-Renner relation and find that the relation can be violated clearly with increasing temperature, and the effect of the magnetic field becomes pronounced around the critical temperature. With different criteria, we analyze the effect of the magnetic field on the chiral phase transition and find that the pseudo-critical temperature of the chiral phase cross, T_c^{χ }, is always enhanced by the magnetic field. Moreover, our calculations indicate that the ρ mesons will get melted as the chiral symmetry has not yet been restored, but the σ meson does not disassociate even at very high temperature. Particularly, it is the first to show that there does not exist a vector meson condensate in the QCD vacuum in the pion-pion scattering scheme.
Mesons in strong magnetic fields: (I) General analyses
Hattori, Koichi; Kojo, Toru; Su, Nan
2016-03-21
Here, we study properties of neutral and charged mesons in strong magnetic fields |eB| >> Λ2QCD with ΛQCD being the QCD renormalization scale. Assuming long-range interactions, we examine magnetic-field dependences of various quantities such as the constituent quark mass, chiral condensate, meson spectra, and meson wavefunctions by analyzing the Schwinger–Dyson and Bethe–Salpeter equations. Based on the density of states obtained from these analyses, we extend the hadron resonance gas (HRG) model to investigate thermodynamics at large B. As B increases the meson energy behaves as a slowly growing function of the meson's transverse momenta, and thus a large number ofmore » meson states is accommodated in the low energy domain; the density of states at low temperature is proportional to B2. This extended transverse phase space in the infrared regime significantly enhances the HRG pressure at finite temperature, so that the system reaches the percolation or chiral restoration regime at lower temperature compared to the case without a magnetic field; this simple picture would offer a gauge invariant and intuitive explanation of the inverse magnetic catalysis.« less
Residual meson-meson interaction from lattice gauge simulation in a simple QED{sub 2+1} model
J. Canosa; H. Fiebig
1995-08-01
The residual interaction for a meson-meson system is computed utilizing the cumulant, or cluster, expansion of the momentum-space time correlation matrix. The cumulant expansion serves to define asymptotic, or free, meson-meson operators. The definition of an effective interaction is then based on a comparison of the full (interacting) and the free (noninteracting) time correlation matrices. The proposed method, which may straight forwardly be transcribed to other hadron-hadron systems, here is applied to a simple 2+1 dimensional U(1) lattice gauge model tuned such that it is confining. Fermions are treated in the staggered scheme. The effective interaction exhibits a repulsive core and attraction at intermediate relative distances. These findings are consistent with an earlier study of the same model utilizing L{umlt u}scher's method where scattering phase shifts are obtained directly.
Intrinsic and dynamically generated scalar meson states
NASA Astrophysics Data System (ADS)
Shakin, C. M.; Wang, Huangsheng
2001-01-01
Recent work by Maltman has given us confidence that our assignment of scalar meson states to various nonets based upon our generalized Nambu-Jona-Lasinio (NJL) model is correct. [For example, in our model the a0(980) and the f0(980) are in the same nonet as the K*0(1430).] In this work we make use of our model to provide a precise definition of ``preexisting'' resonances and ``dynamically generated'' resonances when considering various scalar mesons. [This distinction has been noted by Meissner in his characterization of the f0(400-1200) as nonpreexisting.] We define preexisting (or intrinsic) resonances as those that appear as singularities of the qq¯ T matrix and are in correspondence with qq¯ states bound in the confining field. [Additional singularities may be found when studying the T matrices describing π-π or π-K scattering, for example. Such features may be seen to arise, in part, from t-channel and u-channel ρ exchange in the case of π-π scattering, leading to the introduction of the σ(500-600). In addition, threshold effects in the qq¯ T matrix can give rise to significant broad cross section enhancements. The latter is, in part, responsible for the introduction of the κ(900) in a study of π-K scattering, for example.] We suggest that it is only the intrinsic resonances which correspond to qq¯ quark-model states, and it is only the intrinsic states that are to be used to form quark-model qq¯ nonets of states. [While the κ(900) and σ(500-600) could be placed in a nonet of dynamically generated states, it is unclear whether there is evidence that requires the introduction of other members of such a nonet.] In this work we show how the phenomena related to the introduction of the σ(500-600) and the κ(900) are generated in studies of π-π and π-K scattering, making use of our generalized Nambu-Jona-Lasinio model. We also calculate the decay constants for the a0 and K*0 mesons and compare our results with those obtained by Maltman. We find
NASA Astrophysics Data System (ADS)
Loktik, Oleg
In this thesis, we present the first 2+1 dynamical flavor lattice calculation of the B meson decay constants, fBd and fBs , as well as B0 - B0 mixing parameters in the infinite heavy quark mass limit. We use the chirality-preserving domain-wall formulation for light quarks. We employ an improved lattice formulation of the static approximation for heavy quarks and the Iwasaki gauge action for gluons. An important part of this thesis is the perturbative calculation which relates lattice operators to their continuum counterparts in the MS(NDR) scheme. This calculation had not been done previously for the aforementioned choice of lattice action, and it is discussed in detail in this thesis. Combining our numerical work with the results of the perturbative calculation, we obtain fstatBd = 231(10) +18-23 MeV, fstatBs = 261(10)(22) MeV, and for the mixing parameters, fstatBd BstatBd mb = 237(13) +19-26 MeV, fstatBs BstatBs mb = 262(12)(22) MeV, and xi ( fstatBs BstatBs )/( fstatBd BstatBd ) = 1.11(7) +13-4 , where the first error is statistical and the second is systematic.
On Decays of B Mesons to a Strange Meson and an Eta or Eta' Meson at Babar
Hirschauer, James Francis
2009-01-01
We describe studies of the decays of B mesons to final states ηK*(892), ηK*_{0}(S-wave), ηK*_{2}(1430), and η'K based on data collected with the BABAR detector at the PEP-II asymmetric-energy e^{+}e^{-} collier at the Stanford Linear Accelerator Center. We measure branching fractions and charge asymmetries for the decays B → ηK*, where K* indicates a spin 0, 1, or 2 Kπ system, making first observations of decays to final states ηK^{0*}_{0}(S-wave), ηK^{+*}_{0} (S-wave), and ηK^{0*}_{2}(1430). We measure the time-dependent CP-violation parameters S and C for the decays B^{0} → η'K^{0}, observing CP violation in a charmless B decay with 5σ significance considering both statistical and systematic uncertainties.
Cheng Haiyang; Chua Chunkhiang; Yang Kweichou
2006-01-01
The hadronic charmless B decays into a scalar meson and a pseudoscalar meson are studied within the framework of QCD factorization. Based on the QCD sum rule method, we have derived the leading-twist light-cone distribution amplitudes of scalar mesons and their decay constants. Although the light scalar mesons f{sub 0}(980) and a{sub 0}(980) are widely perceived as primarily the four-quark bound states, in practice it is difficult to make quantitative predictions based on the four-quark picture for light scalars. Hence, predictions are made in the 2-quark model for the scalar mesons. The short-distance approach suffices to explain the observed large rates of f{sub 0}(980)K{sup -} and f{sub 0}(980)K{sup 0} that receive major penguin contributions from the b{yields}sss process. When f{sub 0}(980) is assigned as a four-quark bound state, there exist extra diagrams contributing to B{yields}f{sub 0}(980)K. Therefore, a priori the f{sub 0}(980)K rate is not necessarily suppressed for a four-quark state f{sub 0}(980). The predicted B{sup 0}{yields}a{sub 0}{sup {+-}}(980){pi}{sup {+-}} and a{sub 0}{sup +}(980)K{sup -} rates exceed the current experimental limits, favoring a four-quark nature for a{sub 0}(980). The penguin-dominated modes a{sub 0}(980)K and a{sub 0}(1450)K receive predominant weak annihilation contributions. There exists a twofold experimental ambiguity in extracting the branching ratio of B{sup -}{yields}K{sub 0}*{sup 0}(1430){pi}{sup -}, which can be resolved by measuring other K{sub 0}*(1430){pi} modes in conjunction with the isospin symmetry consideration. Large weak annihilation contributions are needed to explain the K{sub 0}*(1430){pi} data. The decay B{sup 0}{yields}{kappa}{sup +}K{sup -} provides a nice ground for testing the 4-quark and 2-quark nature of the {kappa} meson. It can proceed through W-exchange and hence is quite suppressed if {kappa} is made of two quarks, while it receives a tree contribution if {kappa} is predominately a four
New results on mesons containing strange quarks
Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D'Amore, J.; Dunwoodie, W.; Endorf, R.; Fujii, K.; Hayashii, H.; Iwata, S.
1987-01-01
Recent results of strange and strangeonium mesons are presented. The data come from a high sensitivity study (4.1 ev/nb) of K/sup -/p interactions at 11 GeV/c using the LASS spectrometer at SLAC. The complete leading orbitally-excited K* series up through J/sup P/ = 5/sup -/ and a substantial number of the expected underlying states are observed decaying into K/sup -/..pi../sup +/, anti K/sub 3//sup 0/..pi../sup +/..pi../sup -/, and K eta final states, and new measurements are made of their masses, widths, and branching ratios. Production of strangeonium states via hypercharge exchange is observed into K/sub 3//sup 0/K/sub 3//sup 0/, K/sup -/K/sup +/, and K/sub 3//sup 0/K/sup + -/..pi../sup - +/ final states. The leading orbitally-excited phi series through J/sup P/ = 3/sup -/ is clearly seen and evidence is presented for additional high spin structure in the 2.2 GeV/c/sup 2/ region. No f/sub 2/(1720) is observed. The K/sub 3//sup 0/K/sup + -/..pi../sup - +/ spectrum is dominated by 1/sup +/(K* anti K + anti K* K) production in the region below 1.6 GeV/c/sup 2/. These results are compared with data on the same systems produced by different production mechanisms. 12 refs., 28 figs.
Leskovec, Luka; Lang, C. B.; Mohler, Daniel; Prelovsek, Sasa; Woloshyn, R. M.
2015-11-12
We study the positive parity charmed strange mesons using lattice QCD, the only reliable ab initio method to study QCD at low energies. Especially the experimentally observed $D_{s0}^*(2317)$ and $D_{s1}(2460)$ have challenged theory for quite some time. The dynamical lattice QCD simulations are performed at two distinct pion masses, $m_{\\pi}$ = 266 MeV and 156 MeV, using both $\\bar{c}s$ as well as $DK$ and $D^*K$ scattering operators in the construction of the correlation matrix in order to take into the account threshold effects. While the $J^P = 0^+$ channel benefited most from the inclusion of scattering operators, it was also crucial for the case of the $D_{s1}(2460)$. Using the L\\"uscher method, which relates the finite volume spectrum to the infinite volume scattering matrix, we were able to determine the near threshold behavior of the scattering amplitude. From it we extracted the binding momenta and the masses of the below-threshold bound states $D_{s0}^*(2317)$ and $D_{s1}(2460)$ by determining the pole positions of the scattering amplitudes. Our results compare well with experiment, resolving a long standing discrepancy between theory and experiment.
Electromagnetic Studies of Mesons, Nucleons, and Nuclei
Baker, Oliver K.
2013-08-20
Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty.
Dark photons from charm mesons at LHCb
NASA Astrophysics Data System (ADS)
Ilten, Philip; Thaler, Jesse; Williams, Mike; Xue, Wei
2015-12-01
We propose a search for dark photons A' at the LHCb experiment using the charm meson decay D*(2007 )0→D0A'. At nominal luminosity, D*0→D0γ decays will be produced at about 700 kHz within the LHCb acceptance, yielding over 5 trillion such decays during Run 3 of the LHC. Replacing the photon with a kinetically mixed dark photon, LHCb is then sensitive to dark photons that decay as A'→e+e-. We pursue two search strategies in this paper. The displaced strategy takes advantage of the large Lorentz boost of the dark photon and the excellent vertex resolution of LHCb, yielding a nearly background-free search when the A' decay vertex is significantly displaced from the proton-proton primary vertex. The resonant strategy takes advantage of the large event rate for D*0→D0A' and the excellent invariant-mass resolution of LHCb, yielding a background-limited search that nevertheless covers a significant portion of the A' parameter space. Both search strategies rely on the planned upgrade to a triggerless-readout system at LHCb in Run 3, which will permit the identification of low-momentum electron-positron pairs online during data taking. For dark photon masses below about 100 MeV, LHCb can explore nearly all of the dark photon parameter space between existing prompt-A' and beam-dump limits.
Decoherence induced CPT violation and entangled neutral mesons
Bernabeu, J.; Mavromatos, Nick E.; Sarkar, Sarben
2006-08-15
We discuss two classes of semimicroscopic theoretical models of stochastic spacetime foam in quantum gravity and the associated effects on entangled states of neutral mesons, signalling an intrinsic breakdown of CPT invariance. One class of models deals with a specific model of foam, initially constructed in the context of noncritical (Liouville) string theory, but viewed here in the more general context of effective quantum-gravity models. The relevant Hamiltonian perturbation, describing the interaction of the meson with the foam medium, consists of off-diagonal stochastic metric fluctuations, connecting distinct mass eigenstates (or the appropriate generalization thereof in the case of K-mesons), and it is proportional to the relevant momentum transfer (along the direction of motion of the meson pair). There are two kinds of CPT-violating effects in this case, which can be experimentally disentangled: one (termed '{omega}-effect') is associated with the failure of the indistinguishability between the neutral meson and its antiparticle, and affects certain symmetry properties of the initial state of the two-meson system; the second effect is generated by the time evolution of the system in the medium of the spacetime foam, and can result in time-dependent contributions of the {omega}-effect type in the time profile of the two-meson state. Estimates of both effects are given, which show that, at least in certain models, such effects are not far from the sensitivity of experimental facilities available currently or in the near future. The other class of quantum-gravity models involves a medium of gravitational fluctuations which behaves like a 'thermal bath'. In this model both of the above-mentioned intrinsic CPT violation effects are not valid.
Yukawa Meson, Sakata Model and Baryon-Lepton Symmetry Revisited
NASA Astrophysics Data System (ADS)
Marshak, R. E.
It is difficult for me to grasp that this symposium is celebrating the jubilee of meson theory since I was a junior at Columbia College in 1935. I recall hearing a colloquium by Paul Dirac that year telling an enraptured audience about the infinite sea of negative energy states but I do not recall any special note being taken of the birth of an equally revolutionary concept, the Yukawa meson. Perhaps the reason was the publication of Hideki Yukawa's paper in an inaccessible Japanese journal, perhaps Dirac's electron theory was dealing with the well-known electromagnetic force whereas Yukawa' meson theory was put forth to understand the nature of two new forces - the nuclear and the weak. Whatever the reason, the situation changed drastically when I migrated to Cornell (to do my thesis under Hans Bethe during the years 1937sim39) and found a deep interest in meson theory. Thus, my own scientific career has almost spanned the period since the birth of meson theory but, what is more to the point, it has been strongly influenced by the work of Yukawa and his collaborators. It therefore gives me great pleasure to be able to talk at this MESON 50 symposium. As one of the oldest speakers, I shall respond in a loose way to Professor Maki's invitation to cover ``topics concerning the historical developments of hadron physics''. I shall select several major themes from the Japanese work that have had special interest for me. My remarks will fall under the four headings: (A) Yukawa Meson; (B) Sakata Model; (C) Baryon-Lepton Symmetry; and (D) Extensions of Baryon-Lepton Symmetry.
Hadronic D decays involving even-parity light mesons
Cheng, H.-Y.; Chiang, C.-W.
2010-04-01
We study the hadronic D meson decays into a pseudoscalar meson P and an even-parity meson M, where M represents a scalar meson S, an axial-vector meson A, or a tensor meson T. These decays are first analyzed in the flavor-diagram approach. Fits to the SP modes with S being a nonstrange scalar meson show that neither the simple qq picture nor the q{sup 2}q{sup 2} scheme is favored by data. Current measurements on the AP decays are insufficient for a meaningful analysis. Some TP data are inconsistent with the others. In certain cases, the W-annihilation diagrams indicated by the data are unexpectedly large. As a comparison, we also compute their decay rates in the factorization approach using form factors extracted from the covariant light-front model. We find that factorization works well for Cabibbo-allowed D{sup +{yields}}SP, AP decays free of the weak annihilation contributions (W-exchange or W-annihilation). For the other SP and AP modes, it is necessary to include weak annihilation contributions to account for the data. However, factorization fails for D{yields}TP decays for some unknown reason; the predicted rates are in general too small by at least 2 orders of magnitude compared to experiment. We also examine the finite-width effects of resonances. Some decay modes which are kinematically forbidden become physically allowed due to the finite width of the resonance. We show that the branching fraction of D{sup +{yields}{sigma}{pi}+} extracted from three-body decays is enhanced by a factor of 2, whereas B(D{sup 0{yields}}f{sub 2}(1270)K{sup 0}) is reduced by a factor of 4 by finite-width effects.
Open bottom mesons in a hot asymmetric hadronic medium
NASA Astrophysics Data System (ADS)
Pathak, Divakar; Mishra, Amruta
2015-04-01
The in-medium masses and optical potentials of B and B ¯ mesons are studied in an isospin asymmetric, strange, hot, and dense hadronic environment using a chiral effective model. The chiral SU(3 ) model originally designed for the light-quark sector, is generalized to include the heavy-quark sector (c and b ) to derive the interactions of the B and B ¯ mesons with the light hadrons. Owing to the large mass of bottom quark, we use only the empirical form of these interactions for the desired purpose, while treating the bottom degrees of freedom to be frozen in the medium. Hence, all medium effects are attributable to the in-medium interaction of the light-quark content of these open bottom mesons. Both B and B ¯ mesons are found to experience net attractive interactions in the medium, leading to lowering of their masses in the medium. The mass degeneracy of particles and antiparticles, (B+, B-) as well as (B0, B¯ 0), is observed to be broken in the medium, owing to equal and opposite contributions from a vectorial Weinberg-Tomozawa interaction term. Addition of hyperons to the medium lowers further the in-medium mass for each of these four mesons, while a nonzero isospin asymmetry is observed to break the approximate mass degeneracy of each pair of isospin doublets. These medium effects are found to be strongly density dependent and bear a considerably weaker temperature dependence. The results obtained in the present investigation are compared to predictions from the quark-meson coupling model, heavy meson effective theory, and the QCD sum rule approach.
Suppressed decays of D(s)(+) mesons to two pseudoscalar mesons.
Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Naik, P; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Sanghi, B; Shipsey, I P J; Xin, B
2007-11-01
Using data collected near the D{s}{*+}D{s}{-} peak production energy E_{cm}=4170 MeV by the CLEO-c detector, we study the decays of D{s}{+} mesons to two pseudoscalar mesons. We report on searches for the singly Cabibbo-suppressed D{s}{+} decay modes K{+}eta, K{+}eta', pi{+}K{S}{0}, K{+}pi{0}, and the isospin-forbidden decay mode D{s}{+}-->pi{+}pi{0}. We normalize with respect to the Cabibbo-favored D{s}{+} modes pi{+}eta, pi{+}eta', and K{+}K{S}{0}, and obtain ratios of branching fractions: B(D{s}{+}-->K{+}eta)/B(D{s}{+}-->pi{+}eta)=(8.9+/-1.5+/-0.4)%, B(D{s}{+}-->K{+}eta')/B(D{s}{+}-->pi{+}eta')=(4.2+/-1.3+/-0.3)%, B(D{s}{+}-->pi{+}K{S}{0})/B(D{s}{+}-->K{+}K{S}{0})=(8.2+/-0.9+/-0.2)%, B(D{s}{+}-->K{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})=(5.5+/-1.3+/-0.7)%, and B(D{s}{+}-->pi{+}pi{0})/B(D{s}{+}-->K{+}K{S}{0})<4.1% at 90% C.L., where the uncertainties are statistical and systematic, respectively. PMID:18233066
Medium Modification of the Light Vector Mesons in Nuclei
Nasseripour, Rakhsha; Djalali, Chaden; Wood, Michael; Weygand, Dennis
2008-11-01
Theoretical calculations predict the modification of properties of vector mesons, such as a shift in their masses and/or broadening of their widths in dense nuclear matter. These effects can be related to partial restoration of chiral symmetry at high density or temperature. Photoproduction of vector mesons off nuclei were performed at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). The data were taken with a beam of tagged photons with energies up to 4 GeV on various nuclear targets. The properties of the rho vector mesons were investigated via their rare leptonic decay to e+e?. This decay channel is preferred over hadronic modes in order to eliminate final state interactions in the nuclear matter. The combinatorial background in the mass spectrum was removed by a self-normalizing mixed-event technique. The rho meson mass distributions were extracted for each of the targets. Statistically significant results regarding medium modification of the rho meson in the nuc
Observation of in-medium modifications of the omega meson.
Trnka, D; Anton, G; Bacelar, J C S; Bartholomy, O; Bayadilov, D; Beloglazov, Y A; Bogendörfer, R; Castelijns, R; Crede, V; Dutz, H; Ehmanns, A; Elsner, D; Ewald, R; Fabry, I; Fuchs, M; Essig, K; Funke, Ch; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Höffgen, S; Hoffmeister, P; Horn, I; Hössl, J; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Klein, Frank; Klein, Fritz; Klempt, E; Konrad, M; Kopf, B; Kotulla, M; Krusche, B; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Nanova, M; Novotny, R; Ostrick, M; Pant, L M; van Pee, H; Pfeiffer, M; Roy, A; Radkov, A; Schadmand, S; Schmidt, Ch; Schmieden, H; Schoch, B; Shende, S; Suft, G; Sumachev, V V; Szczepanek, T; Süle, A; Thoma, U; Varma, R; Walther, D; Weinheimer, Ch; Wendel, Ch
2005-05-20
The photoproduction of omega mesons on nuclei has been investigated using the Crystal Barrel/TAPS experiment at the ELSA tagged photon facility in Bonn. The aim is to study possible in-medium modifications of the omega meson via the reaction gamma + A --> omega + X --> pi(0)gamma + X('). Results obtained for Nb are compared to a reference measurement on a LH2 target. While for recoiling, long-lived mesons (pi(0), eta, and eta;(')), which decay outside of the nucleus, a difference in the line shape for the two data samples is not observed, we find a significant enhancement towards lower masses for omega mesons produced on the Nb target. For momenta less than 500 MeV/c an in-medium omega meson mass of M(medium) = [722(+4)(-4)(stat)+35-5(syst)] MeV/c(2) has been deduced at an estimated average nuclear density of 0.6rho(0). PMID:16090166
Hyperfine meson splittings: chiral symmetry versus transverse gluon exchange
Felipe J. Llanes-Estrada; Stephen R. Cotanch; Adam P. Szczepaniak; Eric S. Swanson
2004-02-01
Meson spin splittings are examined within an effective Coulomb gauge QCD Hamiltonian incorporating chiral symmetry and a transverse hyperfine interaction necessary for heavy quarks. For light and heavy quarkonium systems the pseudoscalar-vector meson spectrum is generated by approximate BCS-RPA diagonalizations. This relativistic formulation includes both S and D waves for the vector mesons which generates a set of coupled integral equations. A smooth transition from the heavy to the light quark regime is found with chiral symmetry dominating the /pi-/rho mass difference. A good, consistent description of the observed meson spin splittings and chiral quantities, such as the quark condensate and the /pi mass, is obtained. Similar comparisons with TDA diagonalizations, which violate chiral symmetry, are deficient for light pseudoscalar mesons indicating the need to simultaneously include both chiral symmetry and a hyperfine interaction. The /eta{sub b} mass is predicted to be around 9400 MeV consistent with other theoretical expectations and above the unconfirmed 9300 MeV candidate. Finally, for comparison with lattice results, the J reliability parameter is also evaluated.
Method to study complex systems of mesons in lattice QCD
Detmold, William; Savage, Martin J.
2010-07-30
Correlation functions involving many hadrons allow finite density systems to be explored with Lattice QCD. Recently, systems with up to 12more » $$\\pi^+$$'s or $K^+$'s have been studied to determine the the $3$-$$\\pi^+$$ and $3$-$K^+$ interactions and the corresponding chemical potential has been determined as a function of density in each case. We derive recursion relations between correlation functions that allow us to extend this work to systems of arbitrary numbers of mesons and to systems containing arbitrary different types of mesons such as $$\\pi^+$$'s, $K^+$'s, $D^0$'s and $B^+$'s. These relations allow for the study of finite-density systems in arbitrary volumes, and the study of high-density systems. Systems comprised of up to N=12 m mesons can be explored with Lattice QCD calculations utilizing $m$ different sources for the quark propagators. As the recursion relations require only a small, N-independent, number of operations to derive the N+1 meson contractions from the N meson contractions, they are compuationally feasible.« less
Nonresonant Background in Isobaric Models of Photoproduction of η-Mesons on Nucleons
NASA Astrophysics Data System (ADS)
Tryasuchev, V. A.; Alekseev, B. A.; Yakovleva, V. S.; Kondratyeva, A. G.
2016-07-01
Within the framework of isobaric models of pseudoscalar meson photoproduction, the nonresonant background of photoproduction of η-mesons on nucleons is investigated as a function of energy. A bound on the magnitude of the pseudoscalar coupling constant of the η-meson with a nucleon is obtained: g {ηNN/ 2}/4π ≤ 0.01, and a bound on vector meson exchange models is also obtained.
Nonresonant Background in Isobaric Models of Photoproduction of η-Mesons on Nucleons
NASA Astrophysics Data System (ADS)
Tryasuchev, V. A.; Alekseev, B. A.; Yakovleva, V. S.; Kondratyeva, A. G.
2016-07-01
Within the framework of isobaric models of pseudoscalar meson photoproduction, the nonresonant background of photoproduction of η-mesons on nucleons is investigated as a function of energy. A bound on the magnitude of the pseudoscalar coupling constant of the η-meson with a nucleon is obtained: g η NN 2 /4π ≤ 0.01, and a bound on vector meson exchange models is also obtained.
Properties of L=1 B(1) and B(2)* mesons.
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; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clément, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; de Jong, P; De La Cruz-Burelo, E; Martins, C De Oliveira; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutierrez, P; Gutierrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Y Garzón, G J Otero; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pompos, A; Pope, B G; Popov, A V; Potter, C; da Silva, W L Prado; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, J; Snow, G R; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Strauss, E; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, S; Uvarov, L; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vokac, P; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Weber, G; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Williams, M R J; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yu, C; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G
2007-10-26
This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson. PMID:17995320
D meson-nucleon hadron and nuclear systems
Yasui, Shigehiro; Sudoh, Kazutaka
2010-12-28
We discuss the new exotic nuclei which contains charm and bottom flavors. We consider the possibility of exotic nuclei with D-bar and B mesons. As simplest systems, we consider the systems of D-bar and B bound with one nucleon and two nucleons. As an interaction between D-bar(B) meson and nucleon, we regard the heavy quark symmetry as important. The potential between D-bar(B) meson is supplied by one pion exchange potential as long range force based on heavy quark symmetry. We investigate possible D-barN(BN) bound state with several quantum numbers. We further discuss the possibility of the existence of D-barNN(BNN) as systems with baryon number two.
Hadronic molecules with a D ¯ meson in a medium
NASA Astrophysics Data System (ADS)
Caramés, T. F.; Fontoura, C. E.; Krein, G.; Tsushima, K.; Vijande, J.; Valcarce, A.
2016-08-01
We study the effect of a hot and dense medium on the binding energy of hadronic molecules with open-charm mesons. We focus on a recent chiral quark-model-based prediction of a molecular state in the N D ¯ system. We analyze how the two-body thresholds and the hadron-hadron interactions are modified when quark and meson masses and quark-meson couplings change in a function of the temperature and baryon density according to predictions of the Nambu-Jona-Lasinio model. We find that in some cases the molecular binding is enhanced in medium as compared to their free-space binding. We discuss the consequences of our findings for the search for exotic hadrons in high-energy heavy-ion collisions as well as in the forthcoming facilities FAIR or J-PARC.
Measurement of the B sup 0 -meson lifetime
Wagner, S.R.; Hinshaw, D.A.; Ong, R.A.; Snyder, A.; Abrams, G.; Adolphsen, C.E.; Akerlof, C.; Alexander, J.P.; Alvarez, M.; Amidei, D.; Baden, A.R.; Ballam, J.; Barish, B.C.; Barklow, T.; Barnett, B.A.; Bartelt, J.; Blockus, D.; Bonvicini, G.; Boyarski, A.; Boyer, J.; Brabson, B.; Breakstone, A.; Brom, J.M.; Bulos, F.; Burchat, P.R.; Burke, D.L.; Butler, F.; Calvino, F.; Cence, R.J.; Chapman, J.; Cords, D.; Coupal, D.P.; DeStaebler, H.C.; Dorfan, D.E.; Dorfan, J.M.; Drell, P.S.; Feldman, G.J.; Fernandez, E.; Field, R.C.; Ford, W.T.; Fordham, C.; Frey, R.; Fujino, D.; Gan, K.K.; Gidal, G.; Gladney, L.; Glanzman, T.; Gold, M.S.; Goldhaber, G.; Green, A.; Grosse-Wiesmann, P.; Haggerty, J.; Hanson, G.; Harr, R.; Harris, F.A.; Hawkes, C.M.; Hayes, K.; Herrup, D.; Heusch, C.A.; Himel, T.; Hollebeek, R.J.; Hutchinson, D.; Hylen, J.; Innes, W.R.; Jaffre, M.; Jaros, J.A.; Juricic, I.; Kadyk, J.A.; Karlen, D.; Kent, J.; Klein, S.R.; Koska, W.; Kozanecki, W.; Lankford, A.J.; Larsen, R.R.; LeClair
1990-03-05
We report a measurement of the lifetime of the {ital B}{sup 0} meson based upon 29-GeV {ital e}{sup +}{ital e}{sup {minus}} annihilation data taken with the Mark II detector at the SLAC storage ring PEP. The {ital B}{sup 0} mesons are tagged by their decays into {ital D}{sup *{minus}}{ital e}{sup +}{nu} and {ital D}{sup *{minus}}{mu}{sup +}{nu}, where the {ital D}{sup *{minus}} is tagged by its decay into {pi}{sup {minus}}{ital {bar D}}{sup 0}. We reconstruct the decay vertices of 15 {ital B}{sup 0}-meson candidates and measure the {ital B}{sup 0} lifetime to be 1.20{sup +0.52}{sub {minus}0.36}{sup +0.16}{sub 0.14} psec.
Mesonic Decay of Charm Hypernuclei Λc+
NASA Astrophysics Data System (ADS)
Ghosh, Sabyasachi; Fontoura, Carlos E.; Krein, Gastão
2016-03-01
Λc+ hypernuclei are expected to have binding energies and other properties similar to those of strange hypernuclei in view of the similarity between the quark structures of the strange and charmed hyperons, namely Λ(uds) and Λc+(udc). One striking difference however occurs in their mesonic decays, as there is almost no Pauli blocking in the nucleonic decay of a charm hypernucleus because the final-state nucleons leave the nucleus at high energies. The nuclear medium nevertheless affects the mesonic decays of charm hypernucleus because the nuclear mean fields modify the masses of the charm hyperon. In the present communication we present results of a first investigation of the effects of finite baryon density on different weak mesonic decay channels of the Λc+ baryon. We found a non-negligible reduction of the decay widths as compared to their vacuum values.
Color transparency in incoherent electroproduction of {rho} mesons off nuclei
Nemchik, J.; Kopeliovich, B. Z.; Potashnikova, I. K.
2013-04-15
Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of {rho} meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q{sup 2}. Motivated by the last CLAS data we predict the A, Q{sup 2} and l{sub c} dependence of nuclear transparency for {rho}{sup 0} mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.
Photoproduction of Mesons on Quasi-Free Nucleons
NASA Astrophysics Data System (ADS)
Keshelashvili, I.
2014-11-01
The investigation of excited baryon states is important to understand the underling nature/symmetries of hadronic matter. Historically, the first nucleon excitation experiments have been done using charged pion and kaon secondary beams. Later the antiproton-proton scattering has also been involved. However, since the beginning of the 90's meson photoproduction reactions have been considered as a powerful tool in baryon spectroscopy. In this contribution, we overview our experimental programs conducted at the bremsstrahlung photon beams of the MAMI accelerator in Mainz and the ELSA accelerator in Bonn. The results are differential and total cross sections for photoproduction of light neutral mesons and of meson pairs off quasi-free nucleons bound in the deuteron (and sometimes other light nuclei). The scientific programs of this experiments also include single and double polarization measurements as well.
Meson production in two-photon interactions at LHC energies
Da Silva, D. T.; Goncalves, V. P.; Sauter, W. K.
2013-03-25
The LHC opens a new kinematical regime at high energy, where several questions related to the description of the high-energy regime of the Quantum Chromodynamics (QCD) remain without satisfactory answers. Some open questions are the search for non-q-bar q resonances, the determination of the spectrum of q-bar q states and the identification of states with anomalous {gamma}{gamma} couplings. A possible way to study these problems is the study of meson production in two-photon interactions. In this contribution we calculate the meson production in two-photon interactions at LHC energies considering proton - proton collisions and estimate the total cross section for the production of the mesons {pi}, a, f, {eta} and {chi}.
Distribution amplitudes of radially-excited π and K mesons
NASA Astrophysics Data System (ADS)
Li, B.-L.; Chang, L.; Gao, F.; Roberts, C. D.; Schmidt, S. M.; Zong, H.-S.
2016-06-01
A symmetry-preserving truncation of the two-body bound state problem in relativistic quantum field theory is used to compute the leading-twist parton distribution amplitudes (PDAs) for the first radial excitations of the π and K mesons. In common with ground states in these channels, the PDAs are found to be dilated with respect to the relevant conformal-limit form and skewed toward the heavier valence quark in asymmetric systems. In addition, the PDAs of radially excited pseudoscalar mesons are not positive definite, owing to the fact that dynamical chiral symmetry breaking (DCSB) forces the leptonic decay constant of such states to vanish in the chiral limit. These results highlight that DCSB is expressed visibly in every pseudoscalar meson constituted from light quarks. Hence, so long as its impact is empirically evident in the pseudoscalar members of a given spectrum level, it is unlikely that chiral symmetry is restored in any of the hadrons that populate this level.
Mssm Predictions on Lepton Flavor Violation Decays of Vector Mesons
NASA Astrophysics Data System (ADS)
Yang, Jing; Sun, Ke-Sheng
2012-12-01
In the minimal supersymmetric extension of the Standard Model (MSSM) the interactions between the SUSY particles and the Standard Model (SM) particles can contribute to the lepton flavor violation (LFV) decays of vector mesons at loop level. Taking the constraint on the lightest Higgs mass around 126 GeV, we study these decays by a scan over the parameter space which gives the predictions on μ-e conversion and τ→μγ satisfying the experimental bounds. The branching ratios of the vector mesons decays into eμ are strongly suppressed. However, the branching ratios of the heavy flavor mesons decays into τμ can reach the experimental sensitivity in near future. Therefore, the experimental signals of these decays may serve as a probe of the MSSM.
Probing the Gluon Self-Interaction in Light Mesons
Fischer, Christian S.; Williams, Richard
2009-09-18
We investigate masses and decay constants of light mesons from a coupled system of Dyson-Schwinger and Bethe-Salpeter equations. We explicitly take into account dominant non-Abelian contributions to the dressed quark-gluon vertex stemming from the gluon self-interaction. We construct the corresponding Bethe-Salpeter kernel that satisfies the axial-vector Ward-Takahashi identity. Our numerical treatment fully includes all momentum dependencies with all equations solved completely in the complex plane. This approach goes well beyond the rainbow-ladder approximation and permits us to investigate the influence of the gluon self-interaction on the properties of mesons. As a first result we find indications of a nonperturbative cancellation of the gluon self-interaction contributions and pion cloud effects in the mass of the rho meson.
Charm Meson Spectroscopy at BaBar and CLEO-C
Zghiche, A.; /Annecy, LAPP
2007-10-16
In this mini-review we report on the most recent progress in charm meson spectroscopy. We discuss the precision measurements performed by the BABAR and CLEO-c experiments in the non strange charm meson part and we present the newly discovered strange charmed meson excited states.
Study of Heavy-Light Mesons Properties Via the Variational Method for Cornell Interaction
NASA Astrophysics Data System (ADS)
Hassanabadi, H.; Ghafourian, M.; Rahmani, S.
2016-04-01
Using the variational method we calculate mesonic wave function. We report masses and decay constants for heavy-light mesons. Leptonic decay widths of charmed and beauty mesons are also calculated. The obtained results are compared with the available experimental and theoretical data.
Light O{sup ++} Mesons: Scalargators in Florida
Pennington, M. R.
2010-08-05
Light scalar mesons abound in hadron processes, like the alligators in the Florida Everglades. Moreover, scalars are intimately tied to the vacuum structure of QCD. They are the product of many decays. Consequently, a rich source of recent information about them has come from experiments producing heavy flavour mesons. Indeed, scalars will continue to dominate many of the processes to be studied at forthcoming facilities like BESIII in Beijing, FAIR at GSI Darmstadt and the GlueX experiment at JLab, making an understanding (or at least an excellent and theoretically consistent description) essential for the physics missions of these facilities.
Electromagnetic production of vector mesons at low energies
Oh, Y.; Titov, A. I.; Lee, T.-S. H.
2000-05-17
The authors have investigated exclusive photoproduction of light vector mesons ({omega}, {rho} and {phi}) on the nucleon at low energies. In order to explore the questions concerning the so-called missing nucleon resonances, they first establish the predictions from a model based on the Pomeron and meson exchange mechanisms. They have also explored the contributions due to the mechanisms involving s- and u-channel intermediate nucleon state. Some discrepancies found at the energies near threshold and large scattering angles suggest a possibility of using this reaction to identify the nucleon resonances.
Compton scattering, meson exchange, and the polarizabilities of bound nucleons
NASA Astrophysics Data System (ADS)
Feldman, G.; Mellendorf, K. E.; Eisenstein, R. A.; Federspiel, F. J.; Garino, G.; Igarashi, R.; Kolb, N. R.; Lucas, M. A.; MacGibbon, B. E.; Mize, W. K.; Nathan, A. M.; Pywell, R. E.; Wells, D. P.
1996-11-01
Elastic photon scattering cross sections on 16O have been measured in the energy range 27-108 MeV. These data are inconsistent with a conventional interpretation in which the electric and magnetic polarizabilities of the bound nucleon are unchanged from the free values and the meson-exchange seagull amplitude is taken in the zero-energy limit. Agreement with the data can be achieved by invoking either strongly modified polarizabilities or a substantial energy dependence to the meson-exchange seagull amplitude. It is argued that these seemingly different explanations are experimentally indistinguishable and probably physically equivalent.
Lattice results for low moments of light meson distribution amplitudes
Arthur, R.; Boyle, P. A.; Broemmel, D.; Flynn, J. M.; Rae, T. D.; Sachrajda, C. T. C.; Donnellan, M. A.
2011-04-01
As part of the UKQCD and RBC collaborations'N{sub f}=2+1 domain-wall fermion phenomenology programme, we calculate the first two moments of the light-cone distribution amplitudes of the pseudoscalar mesons {pi} and K and the (longitudinally polarized) vector mesons {rho}, K{sup *}, and {phi}. We obtain the desired quantities with good precision and are able to discern the expected quark-mass dependence of SU(3)-flavor breaking effects. An important ingredient of the calculation is the nonperturbative renormalization of lattice operators using a regularization-independent momentum scheme.
Heavy-light mesons in a relativistic model
NASA Astrophysics Data System (ADS)
Liu, Jing-Bin; Yang, Mao-Zhi
2016-07-01
We study the heavy-light mesons in a relativistic model, which is derived from the Bethe-Salpeter equation by applying the Foldy-Wouthuysen transformation to the heavy quark. The kernel we choose is based on scalar confinement and vector Coulomb potentials. The transverse interaction of the gluon exchange is also taken into account in this model. The spectra and wave functions of D, Ds, B, Bs meson states are obtained. The spectra are calculated up to the order of 1/m Q, and wave functions are treated to leading order. Supported by National Natural Science Foundation of China (11375088, 10975077, 10735080, 11125525)
Charged-particle multiplicities in B-meson decay
Alam, M.S.; Csorna, S.E.; Fridman, A.; Hicks, R.G.; Panvini, R.S.; Andrews, D.; Avery, P.; Berkelman, K.; Cabenda, R.; Cassel, D.G.; DeWire, J.W.; Ehrlich, R.; Ferguson, T.; Gilchriese, M.G.D.; Gittelman, B.; Hartill, D.L.; Herrup, D.; Herzlinger, M.; Holzner, S.; Kandaswamy, J.; Kreinick, D.L.; Mistry, N.B.; Morrow, F.; Nordberg, E.; Perchonok, R.; Plunkett, R.; Silverman, A.; Stein, P.C.; Stone, S.; Weber, D.; Wilcke, R.; Sadoff, A.J.; Bebek, C.; Haggerty, J.; Hempstead, M.; Izen, J.M.; Loomis, W.A.; MacKay, W.W.; Pipkin, F.M.; Rohlf, J.; Tanenbaum, W.; Wilson, R.; Chadwick, K.; Chauveau, J.; Ganci, P.; Gentile, T.; Kagan, H.; Kass, R.; Melissinos, A.C.; Olsen, S.L.; Poling, R.; Rosenfeld, C.; Rucinski, G.; Thorndike, E.H.; Green, J.; Sannes, F.; Skubic, P.; Snyder, A.; Stone, R.; Brody, A.; Chen, A.; Goldberg, M.; Horwitz, N.; Lipari, P.; Kooy, H.; Moneti, G.C.; Pistilli, P.
1982-08-09
The charged multiplicity has been measured at the UPSILON(4S) and a value of 5.75 +- 0.1 +- 0.2 has been obtained for the mean charged multiplicity in B-meson decay. Combining this result with the measurement of prompt letpons from B decay, the values 4.1 +- 0.35 +- 0.2 and 6.3 +- 0.2 +- 0.2 are found for the semileptonic and nonleptonic charged multiplicities, respectively. If b..-->..c dominance is assumed for the weak decay of the B meson, then the semileptonic multiplicity is consistent with the recoil mass determined from the lepton momentum spectrum.
Study of Scalar Mesons and Related Radiative Decays
Deirdre Black; Masayasu Harada; Joseph Schechter
2002-06-01
After a brief review of the puzzling light scalar meson sector of QCD, a brief summary will be given of a paper concerning radiative decays involving the light scalars. There, a simple vector meson dominance model is constructed in an initial attempt to relate a large number of the radiative decays involving a putative scalar nonet to each other. As an application it is illustrated why a{sub 0}(980)-f{sub 0}(980) mixing is not expected to greatly alter the f{sub 0}/a{sub 0} production ratio for radiative {phi} decays.
Rare Electroweak Decays of K and B Mesons
Swee-Ping, Chia
2009-07-07
A phenomenological model is employed to treat the rare decays of mesons with neutrino-antineutrino pair production or charged lepton-antilepton production. The model takes advantage of the fact that inside the hadrons, quarks and antiquarks are tightly bound, and they behave like free particles. As such, the rare decay process can be described in terms of the corresponding quark-level decay process, but with the quarks developing 'dressed' masses because of QCD effects. The 'dressed' quark masses are estimated from the weak decays of the hadrons. With this set of 'dressed' quark masses, a reasonable description of the rare decays of the K and B mesons is obtained.
Hybrid Meson Potentials and the Gluonic van der Waals Force
O. Lakhina; E.S. Swanson
2004-03-01
The chromoelectric polarizability of mesons governs the strength of the gluonic van der Waals force and therefore of non-quark-exchange processes in hadronic physics. We compute the polarizability of heavy mesons with the aid of lattice gauge theory and the Born--Oppenheimer adiabatic expansion. We find that the operator product expansion breaks down at surprisingly large quarks masses due to nonperturbative gluodynamics and that previous conclusions concerning J/{psi}--nuclear matter interactions and J/{psi} dissociation in the quark-gluon plasma must be substantially modified.
Charmed meson decay constants in three-flavor lattice QCD
Aubin, C.; Bernard, C.; DeTar, C.; Di Pierro, M.; Freeland, Elizabeth D.; Gottlieb, Steven; Heller, U.M.; Hetrick, J.E.; El-Khadra, Aida X.; Kronfeld, Andreas S.; Levkova, L.; Mackenzie, P.B.; Menscher, D.; Maresca, F.; Nobes, M.; Okamoto, M.; Renner, D.B.; Simone, J.; Sugar, R.; Toussaint, D.; Trottier, H.D.; /Art Inst. of Chicago /Columbia U. /Washington U., St. Louis /Utah U. /DePaul U. /Indiana U. /APS, New York /U. Pacific, Stockton /Illinois U., Urbana /Fermilab /Cornell U., LEPP /Arizona U. /UC, Santa Barbara /Simon Fraser U.
2005-06-01
The authors present the first lattice QCD calculation with realistic sea quark content of the D{sup +}-meson decay constant f{sub D+}. They use the MILC Collaboration's publicly available ensembles of lattice gauge fields, which have a quark sea with two flavors (up and down) much lighter than a third (strange). They obtain f{sub D+} = 201 {+-} 3 {+-} 17 MeV, where the errors are statistical and a combination of systematic errors. They also obtain f{sub D{sub s}} = 249 {+-} 3 {+-} 16 MeV for the D{sub s} meson.
Quark masses and the meson spectrum: A holographic approach
NASA Astrophysics Data System (ADS)
Afonin, S. S.; Pusenkov, I. V.
2015-09-01
Based on experimental data, we can assume that the radial spectrum of vector mesons with a hidden quark flavor has a Regge form and propose its concrete form. The parameters of the Regge spectrum turn out to depend strongly on the mass of the quarks forming the mesons. We consider the problem of finding the form of these dependences in the framework of the holographic approach to strong interactions. The obtained results agree well with the phenomenology and with models of Veneziano-like dual amplitudes.
D meson hadronic decays at CLEO-c
Yang, Fan; /Fermilab
2011-01-01
The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.
Heavy-light charm mesons spectroscopy and decay widths
NASA Astrophysics Data System (ADS)
Upadhyay, Alka; Batra, Meenakshi; Gupta, Pallavi
2016-05-01
We present the mass formula for heavy-light charm meson at one loop, using heavy quark effective theory. Formulating an effective Lagrangian, the masses of the ground state heavy mesons have been studied in the heavy quark limit, including leading corrections from finite heavy quark masses and nonzero light quark masses, using a constrained fit for the eight equations with 11 parameters including three coupling constants g, h, and g^' }. Masses determined using this approach are fitted to the experimentally known decay widths to estimate the strong coupling constants, showing a better match with available theoretical and experimental data.
Electroweak meson production reaction in the nucleon resonance region
Sato, Toru
2015-10-15
We report on our recent study of the the neutrino-nucleon reaction in the nucleon resonance region. The dynamical reaction model of meson production reaction on the nucleon for the pion and photon induced reaction has been developed in order to investigate the spectrum of nucleon excited state. We have extended this model in order to describe the weak meson production reactions with the πN, ηN, KΛ, KΣ and ππN final states. We also studied the role of the final state interaction in the photon and the neutrino induced pion production reaction on the deuteron around the Δ(1232) resonance region.
Meson Structure in a Relativistic Many-Body Approach
Llanes-Estrada, Felipe J.; Cotanch, Stephen R.
2000-02-07
Results from an extensive relativistic many-body analysis utilizing a realistic effective QCD Hamiltonian are presented for the meson spectrum. A comparative numerical study of the BCS, Tamm-Dancoff (TDA), and RPA treatments provides new, significant insight into the condensate structure of the vacuum, the chiral symmetry governance of the pion, and the meson spin, orbital, and flavor mass splitting contributions. In contrast to a previous glueball application, substantial quantitative differences are computed between TDA and RPA for the light quark sector with the pion emerging as a Goldstone boson only in the RPA. (c) 2000 The American Physical Society.
Study of B Meson Decays with Excited η and η' Mesons
NASA Astrophysics Data System (ADS)
Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G. S.; Battaglia, M.; Brown, D. N.; Button-Shafer, J.; Cahn, R. N.; Groysman, Y.; Jacobsen, R. G.; Kadyk, J. A.; Kerth, L. T.; Kolomensky, Yu. G.; Kukartsev, G.; Lopes Pegna, D.; Lynch, G.; Mir, L. M.; Orimoto, T. J.; Osipenkov, I. L.; Ronan, M. T.; Tackmann, K.; Tanabe, T.; Wenzel, W. A.; Del Amo Sanchez, P.; Hawkes, C. M.; Watson, A. T.; Held, T.; Koch, H.; Pelizaeus, M.; Schroeder, T.; Steinke, M.; Walker, D.; Asgeirsson, D. J.; Cuhadar-Donszelmann, T.; Fulsom, B. G.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Barrett, M.; Khan, A.; Saleem, M.; Teodorescu, L.; Blinov, V. E.; Bukin, A. D.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Bondioli, M.; Curry, S.; Eschrich, I.; Kirkby, D.; Lankford, A. J.; Lund, P.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Abachi, S.; Buchanan, C.; Foulkes, S. D.; Gary, J. W.; Liu, F.; Long, O.; Shen, B. C.; Zhang, L.; Paar, H. P.; Rahatlou, S.; Sharma, V.; Berryhill, J. W.; Campagnari, C.; Cunha, A.; Dahmes, B.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; Beck, T. W.; Eisner, A. M.; Flacco, C. J.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Schalk, T.; Schumm, B. A.; Seiden, A.; Wilson, M. G.; Winstrom, L. O.; Chen, E.; Cheng, C. H.; Fang, F.; Hitlin, D. G.; Narsky, I.; Piatenko, T.; Porter, F. C.; Andreassen, R.; Mancinelli, G.; Meadows, B. T.; Mishra, K.; Sokoloff, M. D.; Blanc, F.; Bloom, P. C.; Chen, S.; Ford, W. T.; Hirschauer, J. F.; Kreisel, A.; Nagel, M.; Nauenberg, U.; Olivas, A.; Smith, J. G.; Ulmer, K. A.; Wagner, S. R.; Zhang, J.; Gabareen, A. M.; Soffer, A.; Toki, W. H.; Wilson, R. J.; Winklmeier, F.; Altenburg, D. D.; Feltresi, E.; Hauke, A.; Jasper, H.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Klose, V.; Kobel, M. J.; Lacker, H. M.; Mader, W. F.; Nogowski, R.; Schubert, J.; Schubert, K. R.; Schwierz, R.; Sundermann, J. E.; Volk, A.; Bernard, D.; Bonneaud, G. R.; Latour, E.; Lombardo, V.; Thiebaux, Ch.; Verderi, M.; Clark, P. J.; Gradl, W.; Muheim, F.; Playfer, S.; Robertson, A. I.; Watson, J. E.; Xie, Y.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Franchini, P.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Santoro, V.; Anulli, F.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Buzzo, A.; Contri, R.; Lo Vetere, M.; Macri, M. M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Santroni, A.; Tosi, S.; Chaisanguanthum, K. S.; Morii, M.; Wu, J.; Dubitzky, R. S.; Marks, J.; Schenk, S.; Uwer, U.; Bard, D. J.; Dauncey, P. D.; Flack, R. L.; Nash, J. A.; Panduro Vazquez, W.; Tibbetts, M.; Behera, P. K.; Chai, X.; Charles, M. J.; Mallik, U.; Ziegler, V.; Cochran, J.; Crawley, H. B.; Dong, L.; Eyges, V.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gao, Y. Y.; Gritsan, A. V.; Guo, Z. J.; Lae, C. K.; Denig, A. G.; Fritsch, M.; Schott, G.; Arnaud, N.; Béquilleux, J.; D'Orazio, A.; Davier, M.; Grosdidier, G.; Höcker, A.; Lepeltier, V.; Le Diberder, F.; Lutz, A. M.; Pruvot, S.; Rodier, S.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, W. F.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Burke, J. P.; Chavez, C. A.; Forster, I. J.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Schofield, K. C.; Touramanis, C.; Bevan, A. J.; George, K. A.; di Lodovico, F.; Menges, W.; Sacco, R.; Cowan, G.; Flaecher, H. U.; Hopkins, D. A.; Paramesvaran, S.; Salvatore, F.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Allison, J.; Barlow, N. R.; Barlow, R. J.; Chia, Y. M.; Edgar, C. L.; Lafferty, G. D.; West, T. J.; Yi, J. I.; Anderson, J.; Chen, C.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Blaylock, G.; Dallapiccola, C.; Hertzbach, S. S.; Li, X.; Moore, T. B.; Salvati, E.; Saremi, S.; Cowan, R.; Dujmic, D.; Fisher, P. H.; Koeneke, K.; Sciolla, G.; Sekula, S. J.; Spitznagel, M.; Taylor, F.; Yamamoto, R. K.; Zhao, M.; Zheng, Y.; McLachlin, S. E.; Patel, P. M.; Robertson, S. H.; Lazzaro, A.; Palombo, F.; Bauer, J. M.; Cremaldi, L.; Eschenburg, V.; Godang, R.; Kroeger, R.; Sanders, D. A.; Summers, D. J.; Zhao, H. W.; Brunet, S.; Côté, D.; Simard, M.; Taras, P.; Viaud, F. B.; Nicholson, H.; de Nardo, G.; Fabozzi, F.; Lista, L.; Monorchio, D.; Sciacca, C.; Baak, M. A.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Benelli, G.; Corwin, L. A.; Honscheid, K.; Kagan, H.; Kass, R.; Morris, J. P.; Rahimi, A. M.; Regensburger, J. J.; Wong, Q. K.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Lu, M.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Gagliardi, N.; Gaz, A.; Margoni, M.; Morandin, M.; Pompili, A.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Voci, C.; Ben-Haim, E.; Briand, H.; Calderini, G.; Chauveau, J.; David, P.; Del Buono, L.; de La Vaissière, Ch.; Hamon, O.; Leruste, Ph.; Malclès, J.; Ocariz, J.; Perez, A.; Prendki, J.; Gladney, L.; Biasini, M.; Covarelli, R.; Manoni, E.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Marchiori, G.; Mazur, M. A.; Morganti, M.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Haire, M.; Biesiada, J.; Elmer, P.; Lau, Y. P.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Baracchini, E.; Bellini, F.; Cavoto, G.; Del Re, D.; di Marco, E.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Jackson, P. D.; Li Gioi, L.; Mazzoni, M. A.; Morganti, S.; Piredda, G.; Polci, F.; Renga, F.; Voena, C.; Ebert, M.; Hartmann, T.; Schröder, H.; Waldi, R.; Adye, T.; Castelli, G.; Franek, B.; Olaiya, E. O.; Ricciardi, S.; Roethel, W.; Wilson, F. F.; Emery, S.; Escalier, M.; Gaidot, A.; Ganzhur, S. F.; Hamel de Monchenault, G.; Kozanecki, W.; Vasseur, G.; Yèche, Ch.; Zito, M.; Chen, X. R.; Liu, H.; Park, W.; Purohit, M. V.; Wilson, J. R.; Allen, M. T.; Aston, D.; Bartoldus, R.; Bechtle, P.; Berger, N.; Claus, R.; Coleman, J. P.; Convery, M. R.; Dingfelder, J. C.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Glanzman, T.; Gowdy, S. J.; Graham, M. T.; Grenier, P.; Hast, C.; Hryn'Ova, T.; Innes, W. R.; Kaminski, J.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Li, S.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Marsiske, H.; Messner, R.; Muller, D. R.; O'Grady, C. P.; Ofte, I.; Perazzo, A.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Stelzer, J.; Su, D.; Sullivan, M. K.; Suzuki, K.; Swain, S. K.; Thompson, J. M.; Va'Vra, J.; van Bakel, N.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Yarritu, A. K.; Yi, K.; Young, C. C.; Burchat, P. R.; Edwards, A. J.; Majewski, S. A.; Petersen, B. A.; Wilden, L.; Ahmed, S.; Alam, M. S.; Bula, R.; Ernst, J. A.; Jain, V.; Pan, B.; Saeed, M. A.; Wappler, F. R.; Zain, S. B.; Krishnamurthy, M.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Izen, J. M.; Lou, X. C.; Ye, S.; Bianchi, F.; Gallo, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Bosisio, L.; Cartaro, C.; Cossutti, F.; Della Ricca, G.; Lanceri, L.; Vitale, L.; Azzolini, V.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D. A.; Oyanguren, A.; Albert, J.; Banerjee, Sw.; Bhuyan, B.; Hamano, K.; Kowalewski, R.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Harrison, P. F.; Ilic, J.; Latham, T. E.; Mohanty, G. B.; Band, H. R.; Chen, X.; Dasu, S.; Flood, K. T.; Hollar, J. J.; Kutter, P. E.; Pan, Y.; Pierini, M.; Prepost, R.; Wu, S. L.; Neal, H.
2008-08-01
Using 383×106 B Bmacr pairs from the BABAR data sample, we report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to K Kmacr * or ηππ final states with mass in the range (1.2 1.8)GeV/c2. We observe a significant enhancement at the low K Kmacr * invariant mass which is interpreted as B+→η(1475)K+, find evidence for the decay B+→η(1295)K+, and place upper limits on the decays B+→η(1405)K+, B+→f1(1285)K+, B+→f1(1420)K+, and B+→ϕ(1680)K+.
Study of B Meson Decays with Excited eta and eta-prime Mesons
Aubert, B.; Bona, M.; Boutigny, D.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prudent, X.; Tisserand, V.; Zghiche, A.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G.S.; Battaglia, M.; Brown, D.N.; Button-Shafer, J.; /Energy Sci. Network /Birmingham U. /Ruhr U., Bochum /Bristol U. /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. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /Frascati /Genoa U. /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /Paris U., VI-VII /Pennsylvania U. /Perugia U. /Pisa U. /Prairie View A-M /Princeton U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.
2008-04-18
Using 383 million B{bar B} pairs from the BABAR data sample, they report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to K{bar K}* or {eta}{pi}{pi} final states with mass in the range (1.2-1.8) GeV/c{sup 2}. They observe a significant enhancement at the low K{bar K}* invariant mass which is interpreted as B{sup +} {yields} {eta}(1475)K{sup +}, find evidence for the decay B{sup +} {yields} {eta}(1295)K{sup +}, and place upper limits on the decays B{sup +} {yields} {eta}(1405)K{sup +}, B{sup +} {yields} f{sub 1}(1285)K{sup +}, B{sup +} {yields} f{sub 1}(1420)K{sup +}, and B{sup +} {yields} {phi}(1680)K{sup +}.
Study of B meson decays with excited eta and eta' mesons.
Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Tico, J Garra; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Osipenkov, I L; Ronan, M T; Tackmann, K; Tanabe, T; Wenzel, W A; del Amo Sanchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Pelizaeus, M; Schroeder, T; Steinke, M; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Watson, J E; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; LoSecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Prendki, J; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hryn'ova, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H
2008-08-29
Using 383 x 10(6) BBover pairs from the BABAR data sample, we report results for branching fractions of six charged B-meson decay modes, where a charged kaon recoils against a charmless resonance decaying to KKover* or etapipi final states with mass in the range (1.2-1.8) GeV/c2. We observe a significant enhancement at the low KKover* invariant mass which is interpreted as B+-->eta(1475)K+, find evidence for the decay B+-->eta(1295)K+, and place upper limits on the decays B+-->eta(1405)K+, B+-->f1(1285)K+, B+-->f1(1420)K+, and B+-->phi(1680)K+. PMID:18851601
Scalar meson f{sub 0}(980) in heavy-meson decays.
El-Bennich, B.; Leitner, O.; Dedonder, J.-P.; Loiseau, B.; Physics; Lab. de Physique Nucleaire et de Hautes Energies; Lab. Nazionali di Frascati
2009-04-01
A phenomenological analysis of the scalar meson f{sub 0}(980) is performed that relies on the quasi-two-body decays D and D{sub s} {yields} f{sub 0}(980)P, with P = {pi}, K. The two-body branching ratios are deduced from experimental data on D or D{sub s} {yields} {pi}{pi}{pi}, K{sup -} K{pi} and from the f{sub 0}(980) {yields} {pi}{sup +}{pi}{sup -} and f{sub 0}(980) {yields} K{sup +}K{sup -} branching fractions. Within a covariant quark model, the scalar form factors for the transitions D and D{sub s} {yields} f{sub 0}(980) are computed. The weak D decay amplitudes, in which these form factors enter, are obtained in the naive factorization approach assuming a q{bar q} state for the scalar and pseudoscalar mesons. They allow to extract information on the f{sub 0}(980) wave function in terms of u{bar u}, d{bar d}, and s{bar s} pairs as well as on the mixing angle between the strange and nonstrange components. The weak transition form factors are modeled by the one-loop triangular diagram using two different relativistic approaches: covariant light-front dynamics and dispersion relations. We use the information found on the f{sub 0}(980) structure to evaluate the scalar and vector form factors in the transitions D and D{sub s} {yields} f{sub 0}(980), as well as to make predictions for B and B{sub s} {yields} f{sub 0}(980), for the entire kinematically allowed momentum range of q{sup 2}.
Observation and study of bottom-meson decays to a charm meson, a proton-antiproton pair, and pions
Hong, Tae Min
2010-04-27
Bottom-meson decays with baryons show two unusual features—the branching fractions are enhanced for multibody decays and the baryon-antibaryon subsystem recoils against the other decay products—and their reasons are not yet well understood. Moreover, measurements using explicit reconstruction techniques constitute only about 1% out of about 8% of such decays. This Dissertation reports the study of ten bottom-meson decays (labeled 0– 9) to a proton-antiproton pair, a charm meson, and a system of up to two pions, using the BABAR Experiment’s 455×10^{6} BB pairs produced with the PEP-II asymmetric-energy e^{+}e^{- }collider at the Stanford Linear Accelerator Center.
Bottom quark mass from {Upsilon} mesons
Hoang, A.H.
1999-01-01
The bottom quark pole mass M{sub b} is determined using a sum rule which relates the masses and the electronic decay widths of the {Upsilon} mesons to large {ital n} moments of the vacuum polarization function calculated from nonrelativistic quantum chromodynamics. The complete set of next-to-next-to-leading order [i.e., O({alpha}{sub s}{sup 2},{alpha}{sub s}v,v{sup 2}) where v is the bottom quark c.m. velocity] corrections is calculated and leads to a considerable reduction of theoretical uncertainties compared to a pure next-to-leading order analysis. However, the theoretical uncertainties remain much larger than the experimental ones. For a two parameter fit for M{sub b}, and the strong
Meson production in photon and neutrino experiments
Shimony, J.S.
1988-01-01
The reaction {gamma}p {yields} {rho}{sup 0}{sub fast}p{pi}{sup +}{pi}{sup {minus}} has been studied with the linearly polarized 20 GeV monochromatic photon beam at the SLAC Hybrid Facility, to test the prediction of s channel helicity conservation in inelastic diffraction for t{prime} < 0.4 (GeV/c){sup 2}. In a sample of 1934 events from this reaction, the {rho}{sup 0} decay angular distributions and spin density matrix elements are consistent with s channel helicity conservation. The {pi}{sup +}{pi}{sup {minus}} mass shape displays the same skewing as seen in the reaction {gamma}p {yields} p{pi}{sup +}{pi}{sup {minus}}, and the p{pi}{sup +}{pi}{sup {minus}} mass distribution compares well and scale according to the vector dominance model with that produced in {pi}{sup {plus minus}}p {yields} p{pi}{sup +}{pi}{sup {minus}}. Coherent production of the a{sub 1} meson has been observed through the reaction {nu}Fr {yields} {mu}{sup {minus}}a{sub 1}{sup +}Fr in the Tohoku 1m freon bubble chamber hybrid system. The bubble chamber was exposed to the Fermilab wideband neutrino beam, generated by 800 GeV protons at the Tevatron. The observed rate from the final charged current sample of 1792 events was 1.1 {plus minus} 0.47%, and the a{sub 1} - W coupling is calculated to be f{sup 2}{sub a}/f{sup 2}{sub {rho}} = 5.2 {plus minus} 2.2. A comparison of the cross section and the kinematical parameters with the theoretical predictions of the vector dominance model, gives reasonable agreement with the data. A Monte-Carlo study was performed to check the possibility of detecting the radiative decay of the D*{sub s} in our bubble chamber. Using the most favorable predicted rate through the {phi} branching ratio, it was determined that three times our data sample would be needed for a one {sigma} effect above background.
Chudakov, Eugene A.; Gevorkyan, Sergey; Somov, Alexander
2016-01-01
We consider photoproduction of omega mesons off complex nuclei to study interactions of transversely and longitudinally polarized vector mesons with nucleons. Whereas the total cross section for interactions of the transversely polarized vector mesons with nucleons sigma_T = sigma(V_T N) can be obtained from coherent photoproduction, measurements of vector meson photoproduction in the incoherent region provide a unique opportunity to extract the not-yet-measured total cross section for longitudinally polarized mesons sigma_L = sigma(V_L N). The predictions for the latter strongly depend on the theoretical approaches. This work is stimulated by the construction of the new experiment GlueX at Jefferson Lab, designed to study the photoproduction of mesons in a large beam energy range up to 12 GeV.