Meson-baryon interaction in the meson exchange picture
M. Döring
2010-09-29
This is the contribution to the proceedings of the MENU 2010 conference. The recent work of Ref. [7] is summarized. Elastic piN scattering and the reaction pi^+ p --> K^+ Sigma^+ 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.
Collision Broadening of the Phi Meson in Baryon Rich Hadronic Matter
Wade Smith; Kevin L. Haglin
1997-10-11
Phi meson-baryon cross sections, estimated within a one-boson-exchange model, serve as input for a calculation of the collision rates in hot hadronic matter. We find that the width of the \\phi meson is modified through collisions with baryons by 1-10 MeV at 160 MeV temperature depending on the baryon fugacity. Thermalization of the \\phi in high energy heavy ion collisions is discussed.
Low energy scattering phase shifts for meson-baryon systems
Detmold, William
2015-01-01
In this work, we calculate meson-baryon scattering phase shifts in four channels using lattice QCD methods. From a set of calculations at four volumes, corresponding to spatial sizes of 2, 2.5, 3, and 4 fm, and a pion mass of m_pi ~ 390 MeV, we determine the scattering lengths and effective ranges for these systems at the corresponding quark masses. We also perform the calculation at a lighter quark mass, m_pi ~ 230 MeV, on the largest volume. Using these determinations, along with those in previous work, we perform a chiral extrapolation of the scattering lengths to the physical point after correcting for the effective range contributions using the multi-volume calculations performed at m_pi ~ 390 MeV.
The rest masses of the electron and muon and of the stable mesons and baryons
E. L. Koschmieder
2007-07-30
The rest masses of the electron, the muon and of the stable mesons and baryons can be explained, within 1% accuracy, with the standing wave model, which uses only photons, neutrinos, charge and the weak nuclear force. We do not need hypothetical particles for the explanation of the masses of the electron, muon, mesons and baryons. We can also explain the charge of the electron, the spin of the electron, of the muon and of the stable baryons, without any additional assumption. We also have determined the rest masses of the electron-, muon- and tau neutrinos and found that the mass of the electron neutrino is equal to the fine structure constant times the mass of the muon neutrino.
Superconformal Baryon-Meson Symmetry and Light-Front Holographic QCD
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dosch, Hans Guenter; de Teramond, Guy F.; Brodsky, Stanley J.
2015-04-10
We construct an effective QCD light-front Hamiltonian for both mesons and baryons in the chiral limit based on the generalized supercharges of a superconformal graded algebra. The superconformal construction is shown to be equivalent to a semi-classical approximation to light-front QCD and its embedding in AdS space. The specific breaking of conformal invariance inside the graded algebra uniquely determines the effective confinement potential. The generalized supercharges connect the baryon and meson spectra to each other in a remarkable manner. In particular, the ?/b1 Regge trajectory is identified as the superpartner of the nucleon trajectory. However, the lowest-lying state on thismore »trajectory, the ?-meson is massless in the chiral limit and has no supersymmetric partner.« less
Strange Content of Baryons at RHIC
B. Hippolyte; for the STAR Collaboration
2003-06-14
Via the study of strange particle production within the STAR experiment, we try to address the surprising amount of baryon transport at the Relativistic Heavy Ion Collider (RHIC). We report here preliminary results showing that, at mid-rapidity and for the top energy of RHIC, the number of created baryons exceeds the number transported from the colliding nuclei. However, thanks to the large acceptance of the experimental setup, one could expect to observe the transition between the ``soft'' regime (low transverse momentum -$\\pt$- region corresponding to a bulk of hot and dense matter hadronizing) and the perturbative one (higher $\\pt$ region) where the fragmentation of incoming partons is supposed to dominate hadron production.}
Determining the Gluonic Content of Isoscalar Mesons
Frank E. Close; Glennys R. Farrar; Zhenping Li
1996-10-08
We develop tools to determine the gluonic content of a resonance of known mass, width and $J^{PC}$ from its branching fraction in radiative quarkonium decays and production cross section in $\\gamma \\gamma$ collisions. We test the procedures by applying them to known $q\\bar{q}$ mesons, then analyze four leading glueball candidates. We identify inconsistencies in data for $J/\\psi \\to \\gamma f_0(1500)$ and $J/\\psi \\to \\gamma f_J(1710)$ whose resolution can quantify their glueball status.When $\\Gamma(f_0(1500) \\to \\gamma \\gamma )$ and $\\Gamma(f_J(1710) \\to \\gamma \\gamma)$ are known, the $n\\bar{n}, s\\bar{s},gg$ mixing angles can be determined. The enigmatic situation in 1400-1500 MeV region of the isosinglet $0^{-+}$ sector is discussed.
Strong coupling constants of heavy baryons with light mesons in QCD
Aliev, T. M.; Azizi, K.; Savci, M.
2012-10-23
The strong coupling constants of the heavy spin-1/2 and spin-3/2 baryons with light pseudoscalar and vector mesons are calculated in the framework of the light cone QCD sum rules. Using the symmetry arguments, some structure independent relations among different correlation functions are obtained. It is shown that all possible transitions are described by only one invariant function, whose explicit expression is structure dependent.
Determining the gluonic content of isoscalar mesons
Close, F.E. [Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (England)] [Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX (England); Farrar, G.R. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States)] [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08855 (United States); Li, Z. [Physics Department, Peking University, Beijing, 100871, Peoples Republic of (China)] [Physics Department, Peking University, Beijing, 100871, Peoples Republic of (China)
1997-05-01
We develop tools to determine the gluonic content of a resonance of known mass, width, and J{sup PC} from its branching fraction in radiative quarkonium decays and production cross section in {gamma}{gamma} collisions. We test the procedures by applying them to known q{bar q} mesons, then analyze four leading glueball candidates. We identify inconsistencies in data for J/{psi}{r_arrow}{gamma}f{sub 0}(1500) and J/{psi}{r_arrow}{gamma}f{sub J}(1710) whose resolution can quantify their glueball status. When {Gamma}(f{sub 0}(1500){r_arrow}{gamma}{gamma}) and {Gamma}(f{sub J}(1710){r_arrow}{gamma}{gamma}) are known, the n{bar n},s{bar s},gg mixing angles can be determined. The enigmatic situation in the 1400-1500 MeV region of the isosinglet 0{sup {minus}+} sector is discussed. {copyright} {ital 1997} {ital The American Physical Society}
Effective field theories of baryons and mesons, or, what do quarks do?
Keaton, G.L. [Lawrence Berkeley Lab., CA (United States). Theoretical Physics Group
1995-06-26
This thesis is an attempt to understand the properties of the protons, pions and other hadrons in terms of their fundamental building blocks. In the first chapter the author reviews several of the approaches that have already been developed. The Nambu-Jona-Lasinio model offers the classic example of a derivation of meson properties from a quark Lagrangian. The chiral quark model encodes much of the intuition acquired in recent decades. The author also discusses the non-linear sigma model, the Skyrme model, and the constituent quark model, which is one of the oldest and most successful models. In the constituent quark model, the constituent quark appears to be different from the current quark that appears in the fundamental QCD Lagrangian. Recently it was proposed that the constituent quark is a topological soliton. In chapter 2 the author investigates this soliton, calculating its mass, radius, magnetic moment, color magnetic moment, and spin structure function. Within the approximations used, the magnetic moments and spin structure function cannot simultaneously be made to agree with the constituent quark model. In chapter 3 the author uses a different plan of attack. Rather than trying to model the constituents of the baryon, he begins with an effective field theory of baryons and mesons, with couplings and masses that are simply determined phenomenologically. Meson loop corrections to baryon axial currents are then computed in the 1/N expansion. It is already known that the one-loop corrections are suppressed by a factor 1/N; here it is shown that the two-loop corrections are suppressed by 1/N{sup 2}. To leading order, these corrections are exactly the same as would be calculated in the constituent quark model. This method therefore offers a different approach to the constituent quark.
Kress, Thomas H.
1998-05-29
Helicity density-matrix elements have been measured for K*{sup 0},{phi}(1020), D* and B* mesons produced inclusively in hadronic Z{sup 0} decays in the OPAL experiment at LEP. Apart from the B*, all show a preference for the helicity-zero state when the meson carries a large fraction of the available energy. The mechanisms which produce such spin alignment in the non-perturbative hadronization of the primary partons to the vector mesons is so far unexplained. Inclusive {lambda} baryons show significant longitudinal polarization at intermediate and high momentum. This may be related to the primary quark and antiquark polarization and the hadronization mechanism which produces the leading baryons.
Determining the Gluonic Content of Isoscalar Mesons
Glennys R. Farrar
1996-12-13
The gluonic widths of four leading glueball candidates are determined from their production in radiative quarkonium decays, allowing quantitative estimation of their glue content. Lattice predictions for the scalar and tensor channels seem to be in reasonable agareement with present data (allowing for mixing with $q \\bar{q}$ states). However there is a glueball-like-state in the pseudoscalar spectrum whose mass is considerably lower than expected from lattice estimates.
Aaltonen, T.; Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; /Purdue U. /Waseda U. /Dubna, JINR
2011-03-01
We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A{sub CP}(B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}) = +0.39 {+-} 0.15 (stat) {+-} 0.08 (syst), and botton baryons, A{sub CP}({Lambda}{sub b}{sup 0} {yields} p{pi}{sup -}) = + 0.03 {+-} 0.17 (stat) {+-} 0.05 (syst) and A{sub CP} ({Lambda}{sub b}{sup 0} {yields} pK{sup -}) = +0.37 {+-} 0.17 (stat) {+-} 0.03 (syst). In addition, they measure CP violation in B{sup 0} {yields} K{sup +}{pi}{sup -} decays with 3.5{sigma} significance, A{sub CP} (B{sup 0} {yields} K{sup +}{pi}{sup -}) = -0.086 {+-} 0.023 (stat) {+-} 0.009 (syst), in agreement with the current world average. Measurements of branching fractions of B{sub s}{sup 0} {yields} K{sup +}K{sup -} and B{sup 0} {yields} {pi}{sup +}{pi}{sup -} decays are also updated.
New thermal model with distinct freeze-out temperatures for baryons and mesons
De Assis, Leonardo P. G.; Duarte, Sergio B.; Chiapparini, Marcelo; Hirsch, Luciana R.; Delfino, Antonio Jr.
2013-05-06
A significant amount of experimental data for particle production in high-energy heavy ion collisions (10 - 200 GeV/A at center of mass) has been accumulated during last years. Many different theoretical attempts have tried to describe these data using thermal models in the approximation of global thermal equilibrium considering only one freeze-out temperature. However the thermal models often are not able to describe adequately the whole multiplicities of hadrons. For instance, the abundance of strange particles is overestimate and the pion yields are underestimated. In this work is presented a thermal hadronic model with two different temperatures in order to describe the baryonic and mesonic chemical freeze-out in ultra-relativistic heavy ion collisions. The model is used to fit the particle population ratios of the hadrons produced in the reaction. The proposal is not merely to incorporate one additional degree of freedom in the adjustment procedure of data, but to present and alternative scenario for the freeze out stage in the collisional proces s. This new reformulated version of thermal model was applied to a set of data, offering a rather good improvement in the fitting of the calculated particle ratios to the data. The results suggest that the introduced model makes the thermal approach more robust to handle with a larger number of colliding systems and a more comprehensive set of reaction observables.
On the baryonic contents of low mass galaxies
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gnedin, Nickolay Y
2012-07-16
The baryonic Tully-Fisher relation is an important observational constraint on cosmological and galactic models. However, it is critical to keep in mind that in observations only stars, molecular, and atomic gas are counted, while the contribution of the ionized gas is almost universally missed. The ionized gas is, however, expected to be present in the gaseous disks of dwarf galaxies simply because they are exposed to the cosmic ionizing background and to the stellar radiation that manages to escape from the central regions of the galactic disks into their outer layers. Such an expectation is, indeed, born out both bymore »cosmological numerical simulations and by simple analytical models.« less
Rare decays of B mesons and baryons at the Tevatron and the LHC
Volpi, Guido; /INFN, Pisa /Siena U.
2008-07-01
The experimental study of rare decays of hadrons containing the b quark has been a fertile ground for some time, and keeps being one of the most interesting subjects in high energy physics. It has improved our understanding of hadronic processes, and allows investigating various aspects of the Standard Model and searching for hints of physics beyond the Standard Model. Examples are the comparison of branching fractions of charmless modes with predictions of models, the constraints on CKM angles (B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B {yields} DK, with D in suppressed modes), the observation of purely leptonic modes (B{sup {+-}} {yields} {tau}{sup {+-}}{nu}), the recently established difference in A{sub CP} between B{sup 0} {yields} K{sup +}{pi}{sup -} and B{sup {+-}} {yields} K{sup {+-}}{pi}{sup 0}, suspected to be a hint new physics. All of them came from a long and successful experimental activity with e{sup +}e{sup -} collisions at the {Upsilon}(4S) resonance. With hadronic colliders now coming into play, the study of rare decays is reaching new heights. Given the high cross section for production of all kinds of B hadrons, the record luminosities now provided by the Tevatron collider, and the LHC program in view for the next years, there is the potential for a rich program of interesting new measurements, including even rarer modes as the B{sub (s)}{sup 0} {yields} {mu}{sup +}{mu}{sup -}, strongly suppressed in the standard model but very sensitive to many NP scenarios. The complexity of the hadronic collision environment, however, requires detectors with high precision and high quality tracking, and a trigger system capable of complex event selections at high rates. The CDF experiment, thanks to a fast trigger on impact parameter, has been able to reconstruct many rare B decays, including previously unobserved modes B{sub s}{sup 0} {yields} K{sup +}K{sup -} and B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}, the latter being particularly interesting for its relationship with the puzzling difference in CP asymmetry between neutral and charged modes. In this thesis we go beyond B mesons, and present the first measurements of Branching fractions and CP asymmetries in charmless b-baryon modes. We study two-body {Lambda}{sub b}{sup 0} decays into final states with a proton and a charged pion or kaon. Their branching fractions can be significantly affected by New Physics contributions; under supersymmetric models with R-parity violation, they can be increased by two orders of magnitude. Their CP-violating asymmetries are also interesting to measure in search for possible further anomalies: then may reach significant size {Omicron}(30%) in the Standard Model, and are also sensitive to possible new physics sources.
Observation and study of the baryonic B-meson decays B?D(*)pp?(?)(?)
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; et al
2012-05-30
We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×10? BB¯¯¯ pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e?e? collider. The branching fractions are measured for the following ten decays: B¯¯¯??D?pp?, B¯¯¯??D*?pp?, B¯¯¯??D?pp???, B¯¯¯??D*?pp???, B??D?pp???, B??D*?pp???, B¯¯¯??D?pp?????, B¯¯¯??D*?pp?????, B??D?pp?????, and B??D*?pp?????. The four B? and the two five-body B¯¯¯? modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(pp?) and M(D(*)?p) invariant-mass distributions show enhancements near threshold values. In the four-body mode B¯¯¯??D?pp???, themore »M(p??) distribution shows a narrow structure of unknown origin near 1.5 GeV/c². The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.« less
Observation and study of the baryonic B-meson decays B?D^{(*)}pp?(?)(?)
del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Hooberman, B.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Tanabe, T.; Hawkes, C. M.; Watson, A. T.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Randle-Conde, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Flanigan, J. M.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Karbach, T. M.; Merkel, J.; Petzold, A.; Spaan, B.; Wacker, K.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; 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.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; 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.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; 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.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Sciolla, G.; Zhao, M.; Lindemann, D.; 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.; Nguyen, X.; Simard, M.; Taras, P.; De Nardo, G.; 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.; Kass, R.; Morris, J. P.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; 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.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.
2012-05-30
We present results for B-meson decay modes involving a charm meson, protons, and pions using 455×10? BB¯¯¯ pairs recorded by the BaBar detector at the SLAC PEP-II asymmetric-energy e?e? collider. The branching fractions are measured for the following ten decays: B¯¯¯??D?pp?, B¯¯¯??D*?pp?, B¯¯¯??D?pp???, B¯¯¯??D*?pp???, B??D?pp???, B??D*?pp???, B¯¯¯??D?pp?????, B¯¯¯??D*?pp?????, B??D?pp?????, and B??D*?pp?????. The four B? and the two five-body B¯¯¯? modes are observed for the first time. The four-body modes are enhanced compared to the three- and the five-body modes. In the three-body modes, the M(pp?) and M(D(*)?p) invariant-mass distributions show enhancements near threshold values. In the four-body mode B¯¯¯??D?pp???, the M(p??) distribution shows a narrow structure of unknown origin near 1.5 GeV/c². The distributions for the five-body modes, in contrast to the others, are similar to the expectations from uniform phase-space predictions.
A Study in Blue: The Baryon Content of Isolated Low Mass Galaxies
Bradford, Jeremy D; Blanton, Michael R
2015-01-01
We study the baryon content of low mass galaxies selected from the Sloan Digital Sky Survey (SDSS DR8), focusing on galaxies in isolated environments where the complicating physics of galaxy-galaxy interactions are minimized. We measure neutral hydrogen (HI) gas masses and line-widths for 148 isolated galaxies with stellar mass between $10^7$ and $10^{9.5} M_{\\odot}$. We compare isolated low mass galaxies to more massive galaxies and galaxies in denser environments by remeasuring HI emission lines from the Arecibo Legacy Fast ALFA (ALFALFA) survey 40% data release. All isolated low mass galaxies either have large atomic gas fractions or large atomic gas fractions cannot be ruled out via their upper limits. We measure a median atomic gas fraction of $f_{\\rm gas} = 0.82 \\pm 0.13$ for our isolated low mass sample with no systems below 0.30. At all stellar masses, the correlations between galaxy radius, baryonic mass and velocity width are not significantly affected by environment. Finally, we estimate a median b...
Philipp Gubler; Keisuke Ohtani
2015-02-07
The behavior of the $\\phi$ meson at finite density is studied, making use of a QCD sum rule approach in combination with the maximum entropy method. It is demonstrated that a possible mass shift of the $\\phi$ in nuclear matter is strongly correlated to the strangeness content of the nucleon, which is proportional to the strange sigma term, $\\sigma_{sN} = m_s \\langle N | \\overline{s}s | N \\rangle$. Our results furthermore show that, depending on the value of $\\sigma_{sN}$, the $\\phi$ meson could receive both a positive or negative mass shift at nuclear matter density. We find that these results depend only weakly on potential modifications of the width of the $\\phi$ meson peak and on assumptions made on the behavior of four-quark condensates at finite density. To check the stability of our findings, we take into account several higher order corrections to the operator product expansion, including $\\alpha_s$-corrections, terms of higher order in the strange quark mass and terms of higher twist that have not been considered in earlier works.
Extracting meson-baryon contributions to the electroexcitation of the N (1675)-5/2 nucleon resonance
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aznauryan, Inna G.; Burkert, Volker D.
2015-07-01
We report on the determination of the electrocouplings for the transition from the proton to the N (1675)-5/2 resonance state using recent differential cross section data on ep ? e?+n by the CLAS collaboration at 1.8 ? Q² -5/2 helicity amplitudes show considerable coupling through the AP1/2 amplitude, that is significantly larger than predicted three-quark contribution to this amplitude. The amplitude AP3/2 is much smaller. Both results are consistent with the predicted sizes of the meson-baryonmore »contributions at Q² ? 1.8 GeV² from the dynamical coupled-channel model.« less
Baryon and chiral symmetry breaking
Gorsky, A. [Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia and Moscow Institute of Physics and Technology (MIPT), Dolgoprudny (Russian Federation); Krikun, A. [NORDITA, KTH Royal Institute of Technology and Stockholm University Stockholm, Sweden and Institute for Theoretical and Experimental Physics (ITEP), Moscow (Russian Federation)
2014-07-23
We briefly review the generalized Skyrmion model for the baryon recently suggested by us. It takes into account the tower of vector and axial mesons as well as the chiral symmetry breaking. The generalized Skyrmion model provides the qualitative explanation of the Ioffe’s formula for the baryon mass.
Alternative large Nc baryons and holography
Carlos Hoyos-Badajoz; Andreas Karch
2009-06-24
In gauge theories in the limit of a large number Nc of colors, baryons are usually described as heavy solitonic objects with mass of order Nc. We discuss an alternative large Nc description both directly in the field theory as well as using holography. In this alternative large Nc limit at least some of the baryons behave like mesons, that is they stay light even at large Nc and their interactions vanish in that limit. For Nc=3 these alternative large Nc baryons are equivalent to the standard baryons. In the holographic description it is manifest that the Regge slopes of mesons and alternative baryons are degenerate.
Alexander Milov
2008-12-21
This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to the light vector mesons; the modification of the spectral shape in search of Chiral symmetry restoration and suppression of the meson production in heavy ion collisions. The experimental results show that the spectral shape of light vector mesons are modified compared to the parameters measured in vacuum. The nature and the magnitude of the modification depends on the energy density of the media in which they are produced. The suppression patterns of light vector mesons are different from the measurements of other mesons and baryons. The mechanisms responsible for the suppression of the mesons are not yet understood. Systematic comparison of existing experimental results points to the missing data which may help to resolve the problem.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dudek, Jozef J.; Edwards, Robert G.
2012-03-21
In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbers $N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$ and $\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible withmore »a color octet gluonic excitation having $J^{P}=1^{+}$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.« less
Baryon Spectroscopy and Resonances
Robert Edwards
2011-12-01
A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of intense effort, notably the ordering of the Roper resonance in the low-lying Nucleon spectrum.
Charmed baryon spectroscopy with Belle
Lesiak, Tadeusz [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-142 Cracow (Poland)
2007-02-27
Recent studies concerning charmed baryon spectroscopy, performed by the Belle collaboration, are briefly described. We report the first observation of two new baryons {xi}cx(2980) and {xi}cx(3077), a precise determination of the masses of {xi}c(2645) and {xi}c(2815), observation of the {lambda}c(2940)+ and experimental constraints on the possible spin-parity of the {lambda}c(2880)+. Observations of several exclusive decays of B mesons to the final states containing charmed baryons are also briefly presented.
Physics Opportunities with Meson Beams
Briscoe, William J; Haberzettl, Helmut; Manley, D Mark; Naruki, Megumi; Strakovsky, Igor I; Swanson, Eric S
2015-01-01
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. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.
Physics Opportunities with Meson Beams
William J. Briscoe; Michael Döring; Helmut Haberzettl; D. Mark Manley; Megumi Naruki; Igor I. Strakovsky; Eric S. Swanson
2015-03-26
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. The present paper summarizes unresolved issues in hadron physics and outlines the vast opportunities and advances that only become possible with such a facility.
Quenched chiral perturbation theory for baryon form factors
Derek B. Leinweber
2001-12-17
A new intuitive method for the rapid calculation of the leading nonanalytic behavior of hadronic observables in quenched chiral perturbation theory is presented. After proving the technique in a consideration of baryon masses, the quenched magnetic moments of octet baryons are addressed. The technique provides a separation of magnetic moment contributions into full, sea, valence and quenched valence contributions, the latter being the conventional view of the quenched approximation. Both baryon mass and meson mass violations of SU(3)-flavor symmetry are accounted for. A comprehensive examination of the individual quark-sector contributions to octet baryon magnetic moments reveals that the u-quark contribution to the proton magnetic moment provides an optimal opportunity to directly view nonanalytic behavior associated with the quenched meson cloud of baryons in the quenched approximation.
M. Abu-Shady
2014-03-13
A baryonic chemical potential is included in the linear sigma model at finite temperature. The effective mesonic potential is numerically calculated using the midpoint technique. The meson masses are investigated as functions of the temperature at fixed value of baryonic chemical potential. The pressure and energy density are investigated as functions of temperature at fixed value of chemical potential. The obtained results are in good agreement in comparison with other techniques. We conclude that the calculated effective potential successfully predicts the meson properties and thermodynamic properties at finite baryonic chemical potential.
Liu, W.; Ko, Che Ming.
2003-01-01
Using hadronic Lagrangians that include the interaction of pentaquark Theta(+) baryon with K and N, we evaluate the cross sections for its production from meson-proton, proton-proton, and photon-proton reactions near threshold.,With empirical...
Kenji Fukushima
2014-10-01
We summarize recent developments in identifying the ground state of dense baryonic matter and beyond. The topics include deconfinement from baryonic matter to quark matter, a diquark mixture, topological effect coupled with chirality and density, and inhomogeneous chiral condensates.
Bernhard Ketzer
2012-08-25
The SU(3)_flavor constituent quark model has been quite successful to explain the properties as well as the observed spectrum of mesons with pseudoscalar and vector quantum numbers. Many radial and orbital excitations of quark-antiquark systems predicted by the model, however, have not yet been observed experimentally or assigned unambiguously. In addition, a much richer spectrum of mesons is expected from QCD, in which quarks interact which each other through the exchange of colored self-interacting gluons. Owing to this particular structure of QCD, configurations are allowed in which an excited gluonic field contributes to the quantum numbers J^{PC} of the meson. States with a valence color-octet qqbar' pair neutralized in color by an excited gluon field are termed hybrids. The observation of such states, however, is difficult because they will mix with ordinary qqbar' states with the same quantum numbers, merely augmenting the observed spectrum for a given J^{PC}. Since the gluonic field may carry quantum numbers other than 0^{++}, however, this can give rise to states with "exotic" quantum numbers J^{PC}=0^{--}, 0^{+-}, 1^{-+}, 2^{+-},... The lowest-lying hybrid multiplet is expected to contain a state with exotic quantum numbers J^{PC}=1^{-+}. The identification of such a state is considered a "smoking gun" for the observation of non-qqbar mesons. The search for hybrid states has been a central goal of hadron spectroscopy in the last 20 years. Ongoing and upcoming high-statistics experiments are expected to shed new light on the existence of such states in nature. In this paper, theoretical predictions for masses and decay modes as well as recent experimental evidence for hybrid meson states and future experimental directions are discussed.
C. A. Meyer; E. S. Swanson
2015-03-04
A review of the theoretical and experimental status of hybrid hadrons is presented. The states $\\pi_1(1400)$, $\\pi_1(1600)$, and $\\pi_1(2015)$ are thoroughly reviewed, along with experimental results from GAMS, VES, Obelix, COMPASS, KEK, CLEO, Crystal Barrel, CLAS, and BNL. Theoretical lattice results on the gluelump spectrum, adiabatic potentials, heavy and light hybrids, and transition matrix elements are discussed. These are compared with bag, string, flux tube, and constituent gluon models. Strong and electromagnetic decay models are described and compared to lattice gauge theory results. We conclude that while good evidence for the existence of a light isovector exotic meson exists, its confirmation as a hybrid meson awaits discovery of its iso-partners. We also conclude that lattice gauge theory rules out a number of hybrid models and provides a reference to judge the success of others.
Baryon Resonances Observed at BES
B. S. Zou
2008-02-01
The $\\psi$ decays provide a novel way to explore baryon spectroscopy and baryon structure. The baryon resonances observed from $\\psi$ decays at BES are reviewed. The implications and prospects at upgraded BESIII/BEPCII are discussed.
Pion Superfluidity and Meson Properties at Finite Isospin Density
Lianyi He; Meng Jin; Pengfei Zhuang
2009-09-27
We investigate pion superfluidity and its effect on meson properties and equation of state at finite temperature and isospin and baryon densities in the frame of standard flavor SU(2) NJL model. In mean field approximation to quarks and random phase approximation to mesons, the critical isospin chemical potential for pion superfluidity is exactly the pion mass in the vacuum, and corresponding to the isospin symmetry spontaneous breaking, there is in the pion superfluidity phase a Goldstone mode which is the linear combination of the normal sigma and charged pion modes. We calculate numerically the gap equations for the chiral and pion condensates, the phase diagrams, the meson spectra, and the equation of state, and compare them with that obtained in other effective models. The competitions between pion superfluidity and color superconductivity at finite baryon density and between pion and kaon superfluidity at finite strangeness density in flavor SU(3) NJL model are briefly discussed.
Precision measurement of the Lambda_b baryon lifetime
LHCb collaboration; R. Aaij; B. Adeva; M. Adinolfi; C. Adrover; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Alessio; M. Alexander; S. Ali; G. Alkhazov; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; S. Amerio; Y. Amhis; L. Anderlini; J. Anderson; R. Andreassen; J. E. Andrews; R. B. Appleby; O. Aquines Gutierrez; F. Archilli; A. Artamonov; M. Artuso; E. Aslanides; G. Auriemma; M. Baalouch; S. Bachmann; J. J. Back; C. Baesso; V. Balagura; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; W. Barter; Th. Bauer; A. Bay; J. Beddow; F. Bedeschi; I. Bediaga; S. Belogurov; K. Belous; I. Belyaev; E. Ben-Haim; G. Bencivenni; S. Benson; J. Benton; A. Berezhnoy; R. Bernet; M. -O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; T. Bird; A. Bizzeti; P. M. Bj\\ornstad; T. Blake; F. Blanc; J. Blouw; S. Blusk; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; A. Borgia; T. J. V. Bowcock; E. Bowen; C. Bozzi; T. Brambach; J. van den Brand; J. Bressieux; D. Brett; M. Britsch; T. Britton; N. H. Brook; H. Brown; I. Burducea; A. Bursche; G. Busetto; J. Buytaert; S. Cadeddu; O. Callot; M. Calvi; M. Calvo Gomez; A. Camboni; P. Campana; D. Campora Perez; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; H. Carranza-Mejia; L. Carson; K. Carvalho Akiba; G. Casse; L. Castillo Garcia; M. Cattaneo; Ch. Cauet; R. Cenci; M. Charles; Ph. Charpentier; P. Chen; N. Chiapolini; M. Chrzaszcz; K. Ciba; X. Cid Vidal; G. Ciezarek; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; C. Coca; V. Coco; J. Cogan; E. Cogneras; P. Collins; A. Comerma-Montells; A. Contu; A. Cook; M. Coombes; S. Coquereau; G. Corti; B. Couturier; G. A. Cowan; D. C. Craik; S. Cunliffe; R. Currie; C. D'Ambrosio; P. David; P. N. Y. David; A. Davis; I. De Bonis; K. De Bruyn; S. De Capua; M. De Cian; J. M. De Miranda; L. De Paula; W. De Silva; P. De Simone; D. Decamp; M. Deckenhoff; L. Del Buono; N. Déléage; D. Derkach; O. Deschamps; F. Dettori; A. Di Canto; H. Dijkstra; M. Dogaru; S. Donleavy; F. Dordei; A. Dosil Suárez; D. Dossett; A. Dovbnya; F. Dupertuis; P. Durante; R. Dzhelyadin; A. Dziurda; A. Dzyuba; S. Easo; U. Egede; V. Egorychev; S. Eidelman; D. van Eijk; S. Eisenhardt; U. Eitschberger; R. Ekelhof; L. Eklund; I. El Rifai; Ch. Elsasser; A. Falabella; C. Färber; G. Fardell; C. Farinelli; S. Farry; D. Ferguson; V. Fernandez Albor; F. Ferreira Rodrigues; M. Ferro-Luzzi; S. Filippov; M. Fiore; C. Fitzpatrick; M. Fontana; F. Fontanelli; R. Forty; O. Francisco; M. Frank; C. Frei; M. Frosini; S. Furcas; E. Furfaro; A. Gallas Torreira; D. Galli; M. Gandelman; P. Gandini; Y. Gao; J. Garofoli; P. Garosi; J. Garra Tico; L. Garrido; C. Gaspar; R. Gauld; E. Gersabeck; M. Gersabeck; T. Gershon; Ph. Ghez; V. Gibson; L. Giubega; V. V. Gligorov; C. Göbel; D. Golubkov; A. Golutvin; A. Gomes; P. Gorbounov; H. Gordon; M. Grabalosa Gándara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graugés; G. Graziani; A. Grecu; E. Greening; S. Gregson; P. Griffith; O. Grünberg; B. Gui; E. Gushchin; Yu. Guz; T. Gys; C. Hadjivasiliou; G. Haefeli; C. Haen; S. C. Haines; S. Hall; B. Hamilton; T. Hampson; S. Hansmann-Menzemer; N. Harnew; S. T. Harnew; J. Harrison; T. Hartmann; J. He; T. Head; V. Heijne; K. Hennessy; P. Henrard; J. A. Hernando Morata; E. van Herwijnen; A. Hicheur; E. Hicks; D. Hill; M. Hoballah; C. Hombach; P. Hopchev; W. Hulsbergen; P. Hunt; T. Huse; N. Hussain; D. Hutchcroft; D. Hynds; V. Iakovenko; M. Idzik; P. Ilten; R. Jacobsson; A. Jaeger; E. Jans; P. Jaton; A. Jawahery; F. Jing; M. John; D. Johnson; C. R. Jones; C. Joram; B. Jost; M. Kaballo; S. Kandybei; W. Kanso; M. Karacson; T. M. Karbach; I. R. Kenyon; T. Ketel; A. Keune; B. Khanji; O. Kochebina; I. Komarov; R. F. Koopman; P. Koppenburg; M. Korolev; A. Kozlinskiy; L. Kravchuk; K. Kreplin; M. Kreps; G. Krocker; P. Krokovny; F. Kruse; M. Kucharczyk; V. Kudryavtsev; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; D. Lambert; R. W. Lambert; E. Lanciotti; G. Lanfranchi; C. Langenbruch; T. Latham; C. Lazzeroni; R. Le Gac; J. van Leerdam; J. -P. Lees; R. Lefèvre; A. Leflat; J. Lefrançois; S. Leo; O. Leroy; T. Lesiak; B. Leverington; Y. Li; L. Li Gioi; M. Liles; R. Lindner; C. Linn; B. Liu; G. Liu; S. Lohn; I. Longstaff; J. H. Lopes; N. Lopez-March; H. Lu; D. Lucchesi; J. Luisier; H. Luo; F. Machefert; I. V. Machikhiliyan; F. Maciuc; O. Maev; S. Malde; G. Manca; G. Mancinelli; J. Maratas; U. Marconi; P. Marino; R. Märki; J. Marks; G. Martellotti; A. Martens; A. Martín Sánchez; M. Martinelli; D. Martinez Santos; D. Martins Tostes; A. Massafferri; R. Matev; Z. Mathe; C. Matteuzzi; E. Maurice; A. Mazurov; B. Mc Skelly; J. McCarthy; A. McNab; R. McNulty; B. Meadows; F. Meier; M. Meissner; M. Merk; D. A. Milanes; M. -N. Minard; J. Molina Rodriguez; S. Monteil; D. Moran; P. Morawski; A. Mordà; M. J. Morello; R. Mountain; I. Mous; F. Muheim; K. Müller; R. Muresan
2013-07-31
The ratio of the \\Lambda b baryon lifetime to that of the B0 meson is measured using 1.0/fb of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The \\Lambda b baryon is observed for the first time in the decay mode \\Lambda b -> J/\\psi pK-, while the B0 meson decay used is the well known B0 -> J/\\psi pi+K- mode, where the pi+ K- mass is consistent with that of the K*0(892) meson. The ratio of lifetimes is measured to be 0.976 +/- 0.012 +/- 0.006, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations of the B0 meson lifetime, the \\Lambda b lifetime is found to be 1.482 +/- 0.018 +/- 0.012 ps. In both cases the first uncertainty is statistical and the second systematic.
Charmed Bottom Baryon Spectroscopy
Brown, Zachary S.; Detmold, William; Meinel, Stefan; Orginos, Kostas
2014-11-01
The spectrum of doubly and triply heavy baryons remains experimentally unexplored to a large extent. Although the detection of such heavy particle states may lie beyond the reach of exper- iments for some time, it is interesting compute this spectrum from QCD and compare results between lattice calculations and continuum theoretical models. Several lattice calculations ex- ist for both doubly and triply charmed as well as doubly and triply bottom baryons. Here, we present preliminary results from the first lattice calculation of doubly and triply heavy baryons including both charm and bottom quarks. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. We present preliminary results for the ground state spectrum.
An Overview of Meson-Nuclear Physics
A. W. Thomas
2010-11-17
This conference covers an extremely broad range of topics and in just a few pages it is impossible to even touch on all the areas which will be discussed. We have chosen to summarise just one area where there has recently been impressive progress, namely our quantitative understanding of strangeness in the nucleon. We also discuss a couple of examples where theoretical progress is of direct importance for future experiments as well as for the interpretation of hitherto anomalous results. Finally we make some remarks on meson and baryon spectroscopy and the exciting array of new facilities that are coming on-line in the near future.
Suzuki, Mahiko
2005-05-13
We extend the perturbative argument of helicity amplitudes to the two-body baryonic decays of B decays.
Amplitude Analysis for Mesons and Baryons: Tools and Technology
C. Hanhart
2015-12-07
In these proceedings some facts about resonances are discussed focussing on the analytic properties of resonant amplitudes with special emphasis on model independent analyses. As an illustrative example of the latter point the decays B and B_s to J/psi pi pi are discussed in some detail.
Stealth Dark Matter: Dark scalar baryons through the Higgs portal
Thomas Appelquist; Richard C. Brower; Michael I. Buchoff; George T. Fleming; Xiao-Yong Jin; Joe Kiskis; Graham D. Kribs; Ethan T. Neil; James C. Osborn; Claudio Rebbi; Enrico Rinaldi; David Schaich; Chris Schroeder; Sergey Syritsyn; Pavlos Vranas; Evan Weinberg; Oliver Witzel
2015-05-28
We present a new model of "Stealth Dark Matter": a composite baryonic scalar of an $SU(N_D)$ strongly-coupled theory with even $N_D \\geq 4$. All mass scales are technically natural, and dark matter stability is automatic without imposing an additional discrete or global symmetry. Constituent fermions transform in vector-like representations of the electroweak group that permit both electroweak-breaking and electroweak-preserving mass terms. This gives a tunable coupling of stealth dark matter to the Higgs boson independent of the dark matter mass itself. We specialize to $SU(4)$, and investigate the constraints on the model from dark meson decay, electroweak precision measurements, basic collider limits, and spin-independent direct detection scattering through Higgs exchange. We exploit our earlier lattice simulations that determined the composite spectrum as well as the effective Higgs coupling of stealth dark matter in order to place bounds from direct detection, excluding constituent fermions with dominantly electroweak-breaking masses. A lower bound on the dark baryon mass $m_B \\gtrsim 300$ GeV is obtained from the indirect requirement that the lightest dark meson not be observable at LEP II. We briefly survey some intriguing properties of stealth dark matter that are worthy of future study, including: collider studies of dark meson production and decay; indirect detection signals from annihilation; relic abundance estimates for both symmetric and asymmetric mechanisms; and direct detection through electromagnetic polarizability, a detailed study of which will appear in a companion paper.
Charmed Bottom Baryon Spectroscopy
Zachary Brown, William Detmold, Stefan Meinel, Konstantinos Orginos
2012-09-01
The arena of doubly and triply heavy baryons remains experimentally unexplored to a large extent. This has led to a great deal of theoretical effort being put forth in the calculation of mass spectra in this sector. Although the detection of such heavy particle states may lie beyond the reach of experiments for some time, it is interesting to compare results between lattice QCD computations and continuum theoretical models. Several recent lattice QCD calculations exist for both doubly and triply charmed as well as doubly and triply bottom baryons. In this work we present preliminary results from the first lattice calculation of the mass spectrum of doubly and triply heavy baryons including both charm and bottom quarks. The wide range of quark masses in these systems require that the various flavors of quarks be treated with different lattice actions. We use domain wall fermions for 2+1 flavors (up down and strange) of sea and valence quarks, a relativistic heavy quark action for the charm quarks, and non-relativistic QCD for the heavier bottom quarks. The calculation of the ground state spectrum is presented and compared to recent models.
Quark Contributions to Baryon Magnetic Moments in Full, Quenched and Partially Quenched QCD
Derek B. Leinweber
2004-06-02
The chiral nonanalytic behaviour of quark-flavor contributions to the magnetic moments of octet baryons are determined in full, quenched and partially-quenched QCD, using an intuitive and efficient diagrammatic formulation of quenched and partially-quenched chiral perturbation theory. The technique provides a separation of quark-sector magnetic-moment contributions into direct sea-quark loop, valence-quark, indirect sea-quark loop and quenched valence contributions, the latter being the conventional view of the quenched approximation. Both meson and baryon mass violations of SU(3)-flavor symmetry are accounted for. Following a comprehensive examination of the individual quark-sector contributions to octet baryon magnetic moments, numerous opportunities to observe and test the underlying structure of baryons and the nature of chiral nonanalytic behavior in QCD and its quenched variants are discussed. In particular, the valence u-quark contribution to the proton magnetic moment provides the optimal opportunity to directly view nonanalytic behavior associated with the meson cloud of full QCD and the quenched meson cloud of quenched QCD. The u quark in Sigma^+ provides the best opportunity to display the artifacts of the quenched approximation.
Baryon resonances coupled to Pion-Nucleon states in lattice QCD
Valentina Verduci; Christian B. Lang
2014-12-01
In recent years the study of two particle systems on the lattice has led to excellent results in the meson sector of the QCD spectrum, however baryon resonances mostly remain unexplored. We present a study of pion-nucleon systems as decay product of baryon resonances in different channels, with special focus on the nucleon spectrum. We evaluate the correlation functions of single and multi particle interpolators. All the Wick contributions are explicitly computed and the consequences of reduced symmetries in moving frames are taken into account. We discuss the theoretical setup together with results for $n_f=2$ mass degenerate light quarks.
Hyperons: Insights into baryon structures
Lach, J.
1991-08-01
The baryon octet is composed mainly of hyperons. Modern high energy hyperon beams provide a tool for the study of hyperon static properties and interactions. Experiments with these beams have provided new insights into hyperon rare decays, magnetic moments, and interactions. These experiments provide us with insights into the strong, weak, and electromagnetic structure of the baryons. 65 refs., 45 figs., 5 tabs.
$?$ Meson Decays of Heavy Hybrid Mesons
Liang Zhang; Peng-Zhi Huang
2015-05-04
We calculate the $\\rho$ meson couplings between heavy hybrid doublets H^h/S^h/M^h/T^h and the ordinary q\\bar{Q} doublets in the framework of 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.
Phenomenology of a pseudoscalar glueball and charmed mesons
Eshraim, Walaa I
2015-01-01
We study the vacuum properties of the pseudoscalar glueball and charmed mesons by using the so-called extended Linear Sigma Model (eLSM) containing scalar, pseudoscalar, vector and axial-vector states. We calculate the mesonic and baryonic decays of the pseudoscalar glueball, where we fixed its mass to $2.6$ GeV, as predicted by lattice-QCD simulations, and take a closer look at the scalar-isoscalar decay channel. As a second step, we enlarge the so-called extended linear Sigma model (eLSM) by including the charm quark to a global $U(4)_r\\times U(4)_l$ chiral symmetry. Most of the parameters of the model have been determined in a previous work by fitting hadron properties involving three quark flavours. Only three new parameters, all related to the current charm quark mass, appear when introducing charmed mesons. We compute charmed mesons masses, weak decay constants, and strong decay widths of (open and hidden) charmed mesons. Moreover, we calculate the decay width of a pseudoscalar ground state charmonium $...
Baryon Transition in Holographic QCD
Si-wen Li
2015-09-24
We propose a mechanism of holographic baryon transition in the Sakai-Sugimoto (SS) model: baryons in this model can jump to different states under the mediated effect of gravitons (or glueballs by holography). We consider a time-dependent gravitational perturbation from M5-brane solution of D=11 supergravity and by employing the relations between 11D M-theory and IIA string theory, we get its 10 dimensional counterpart in the SS model. Such a perturbation is received by the D4-branes wrapped on the $S^{4}$ part of the 10D background, namely the baryon vertex. Technically, baryons in the SS model are described by BPST instanton ansatz and their dynamics can be analyzed using the quantum mechanical system in the instanton's moduli space. In this way, different baryonic states are marked by quantum numbers of moduli space quantum mechanics. By holographic spirit, the gravitational perturbation enters the Hamiltonian as a time-dependent perturbation and it is this time-dependent perturbative Hamiltonian produces the transition between different baryonic states. We calculate the transition probability and get the selection rule and also compute the condition for baryon transition and give the possible transition processes in the limit $\\omega\\gg\\left|\\vec{k}\\right|^{2}$. Since in 10D language, the fluctuation from 11D metric are the perturbation of 10D metric and dilaton which are the modes carried by close strings, thus from the string theory point of view, our proposition can be accounted as the baryonic D4 brane jumps to different states by emitting or absorbing close strings coming from the bulk. In the viewpoints of QCD, it could be interpreted as that baryons transform to different states by interacting with glueballs as a low energy effective theory.
F. Iddir; L. Semlala
2006-11-25
We estimate the ground state masses of the heavy hybrid mesons using a phenomenological QCD-type potential. 0^{- -},1^{- -},0^{- +},1^{- +} and 0^{+ -} J^{PC} states are considered.
Meson photoproduction in the first and second resonance region
B. Krusche
2003-04-02
The study of baryon resonances via meson photoproduction reactions on the free proton and on nucleons in the nuclear medium is discussed. Special emphasis is laid on the production of neutral mesons which due to the suppression of non-resonant backgrounds are particularly well suited for the study of excited states of the nucleon. Experiments carried out during the last ten years with the TAPS-detector at the Mainz Microtron (MAMI) have very significantly contributed to a detailed investigation of the low lying nucleon resonances P33(1232), D13(1520) and S11(1535). The most recent results from single and double pion production and from eta-photoproduction are summarised.
Polarization Observables in the Photoproduction of Two Pseudoscalar Mesons
Winston Roberts
2005-10-12
The many polarization observables that can be measured in process like {gamma}N {yields} M{sub 1}M{sub 2}B, where M{sub 1} and M{sub 2} are pseudoscalar mesons and B is a spin-1/2 baryon, are discussed. The relationships among these observables, their symmetries, as well as inequalities that they satisfy are briefly discussed. Within the context of a particular model for {gamma}N {yields} NKK, some of the observables are calculated, and their sensitivity to the ingredients of the model, and hence to the underlying dynamics of the process, are discussed.
Static-light meson-meson potentials
Gunnar Bali; Martin Hetzenegger
2010-11-02
We investigate potentials between pairs of static-light mesons in Nf=2 Lattice QCD, in different spin channels. The question of attraction and repulsion is particularly interesting with respect to the X(3872) charmonium state and charged candidates such as the Z+(4430). We employ the nonperturbatively improved Sheikholeslami-Wohlert fermion and the Wilson gauge actions at a lattice spacing a approx. 0.084 fm and a pseudoscalar mass mPS approx. 760 MeV. We use stochastic all-to-all propagator techniques, improved by a hopping parameter expansion. The analysis is based on the variational method, utilizing various source and sink interpolators.
Search for Low Mass Exotic mesonic structures. Part I: experimental results
B. Tatischeff; E. Tomasi-Gustafsson
2007-10-09
Recently, several papers discussed on the existence of a low mass new structure at a mass close to M=214.3 MeV. It was suggested that the $\\Sigma^{+}$ disintegration: $\\Sigma^{+}\\to$pP$^{0}$, P$^{0}\\to\\mu^{-}\\mu^{+}$ proceeds through an intermediate particle P$^{0}$ having such mass. The present work intends to look at other new or available data, in order to observe the eventual existence of small narrow peaks or shoulders in very low mesonic masses. Indeed narrow structures were already extracted from various data in dibaryons, baryons and mesons (at larger masses that those studied here).
On finite volume effects in the chiral extrapolation of baryon masses
M. F. M. Lutz; R. Bavontaweepanya; C. Kobdaj; K. Schwarz
2014-07-25
We perform an analysis of the QCD lattice data on the baryon octet and decuplet masses based on the relativistic chiral Lagrangian. The baryon self energies are computed in a finite volume at next-to-next-to-next-to leading order (N$^3$LO), where the dependence on the physical meson and baryon masses is kept. The number of free parameters is reduced significantly down to 12 by relying on large-$N_c$ sum rules. Altogether we describe accurately more than 220 data points from six different lattice groups, BMW, PACS-CS, HSC, LHPC, QCDSF-UKQCD and NPLQCD. Values for all counter terms relevant at N$^3$LO are predicted. In particular we extract a pion-nucleon sigma term of 39$_{-1}^{+2}$ MeV and a strangeness sigma term of the nucleon of $\\sigma_{sN} = 84^{+ 28}_{-\\;4}$ MeV. The flavour SU(3) chiral limit of the baryon octet and decuplet masses is determined with $(802 \\pm 4)$ MeV and $(1103 \\pm 6)$ MeV. Detailed predictions for the baryon masses as currently evaluated by the ETM lattice QCD group are made.
Vicente Vento
2015-05-20
Calculations in unquenched QCD for the scalar glueball spectrum have confirmed previous results of Gluodynamics finding a glueball at ~ 1750 MeV. I analyze the implications of this discovery from the point of view of glueball-meson mixing at the light of the experimental scalar sprectrum.
Partonic flow and $?$-meson production in Au+Au collisions at $\\sqrt{s_{NN}}$ = 200 GeV
B. I. Abelev
2007-03-20
We present first measurements of the $\\phi$-meson elliptic flow ($v_{2}(p_{T})$) and high statistics $p_{T}$ distributions for different centralities from $\\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at RHIC. In minimum bias collisions the $v_{2}$ of the $\\phi$ meson is consistent with the trend observed for mesons. The ratio of the yields of the $\\Omega$ to those of the $\\phi$ as a function of transverse momentum is consistent with a model based on the recombination of thermal $s$ quarks up to $p_{T}\\sim 4$ GeV/$c$, but disagrees at higher momenta. The nuclear modification factor ($R_{CP}$) of $\\phi$ follows the trend observed in the $K^{0}_{S}$ mesons rather than in $\\Lambda$ baryons, supporting baryon-meson scaling. Since $\\phi$-mesons are made via coalescence of seemingly thermalized $s$ quarks in central Au+Au collisions, the observations imply hot and dense matter with partonic collectivity has been formed at RHIC.
Kenji Fukukawa; Yoshikazu Fujiwara
2011-02-15
The neutron-deuteron (nd) scattering is solved in the Faddeev formalism, employing the energy-independent version of the quark-model baryon-baryon interaction fss2. The differential cross sections and the spin polarization of the elastic scattering up to the neutron incident energy $E_n=65$ MeV are well reproduced without reinforcing fss2 with the three-body force. The vector analyzing-power of the neutron, $A_y(\\theta)$, in the energy region $E_n$ < 25 MeV is largely improved in comparison with the predictions by the meson-exchange potentials, thus yielding a partial solution of the long-standing $A_y$-puzzle owing to the nonlocality of the short-range repulsion produced by the quark-model baryon-baryon interaction. The large Coulomb effect in the vector and tensor analyzing-powers in $E_n$ < 10 MeV is also analyzed based on the Vincent and Phatak method and recent detailed studies by other authors.
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.
Light Meson Distribution Amplitudes
R. Arthur; P. A. Boyle; D. Brömmel; M. A. Donnellan; J. M. Flynn; A. Jüttner; H. Pedroso de Lima; T. D. Rae; C. T. Sachrajda; B. Samways
2010-11-12
We calculated the first two moments of the light-cone distribution amplitudes for the pseudoscalar mesons ($\\pi$ and $K$) and the longitudinally polarised vector mesons ($\\rho$, $K^*$ and $\\phi$) as part of the UKQCD and RBC collaborations' $N_f=2+1$ domain-wall fermion phenomenology programme. These quantities were obtained with a good precision and, in particular, the expected effects of $SU(3)$-flavour symmetry breaking were observed. Operators were renormalised non-perturbatively and extrapolations to the physical point were made, guided by leading order chiral perturbation theory. The main results presented are for two volumes, $16^3\\times 32$ and $24^3\\times 64$, with a common lattice spacing. Preliminary results for a lattice with a finer lattice spacing, $32^3\\times64$, are discussed and a first look is taken at the use of twisted boundary conditions to extract distribution amplitudes.
Excited Baryons in Holographic QCD
de Teramond, Guy F.; /Costa Rica U.; Brodsky, Stanley J.; /SLAC /Southern Denmark U., CP3-Origins
2011-11-08
The light-front holographic QCD approach is used to describe baryon spectroscopy and the systematics of nucleon transition form factors. Baryon spectroscopy and the excitation dynamics of nucleon resonances encoded in the nucleon transition form factors can provide fundamental insight into the strong-coupling dynamics of QCD. The transition from the hard-scattering perturbative domain to the non-perturbative region is sensitive to the detailed dynamics of confined quarks and gluons. Computations of such phenomena from first principles in QCD are clearly very challenging. The most successful theoretical approach thus far has been to quantize QCD on discrete lattices in Euclidean space-time; however, dynamical observables in Minkowski space-time, such as the time-like hadronic form factors are not amenable to Euclidean numerical lattice computations.
Connecting the Baryons: Multiwavelength Data for SKA HI Surveys
Meyer, Martin; Obreschkow, Danail; Driver, Simon; Staveley-Smith, Lister; Zwaan, Martin
2015-01-01
The science achievable with SKA HI surveys will be greatly increased through the combination of HI data with that at other wavelengths. These multiwavelength datasets will enable studies to move beyond an understanding of HI gas in isolation to instead understand HI as an integral part of the highly complex baryonic processes that drive galaxy evolution. As they evolve, galaxies experience a host of environmental and feedback influences, many of which can radically impact their gas content. Important processes include: accretion (hot and cold mode, mergers), depletion (star formation, galactic winds, AGN), phase changes (ionised/atomic/molecular), and environmental effects (ram pressure stripping, tidal effects, strangulation). Governing all of these to various extents is the underlying dark matter distribution. In turn, the result of these processes can significantly alter the baryonic states in which material is finally observed (stellar populations, dust, chemistry) and its morphology (galaxy type, bulge/d...
Omega baryon via Oort's Method
R. G. Carlberg; S. L. Morris; H. K. C. Yee; E. Ellingson; R. Abraham; H. Lin; D. Schade; P. Gravel; C. J. Pritchet; T. Smecker-Hane; F. D. A. Hartwick; J. E. Hesser; J. B. Hutchings; J. B. Oke
1997-06-12
The baryon density of the universe is equal to the product of the baryon-to-light ratio, M_b/L, and the luminosity density, j. We estimate M_b/L as the sum of the masses of the X-ray gas and the visible stars in a rich cluster of galaxies divided by the luminosity of the cluster galaxies in precisely the same sky aperture. We evaluate the gas-to-light ratio derived from the EMSS detect cell flux and the CNOC cluster redshift survey galaxies. After making an aperture correction to an effective overdensity of 500rho_c, we find that Omega_gas=0.012-0.016 h^-3/2, depending on the galaxy fading correction. Adding in the galaxy baryons at a mass-to-light ratio of 5 Msun/Lsun, equivalent to Omega_stars=0.003h^-1, we find that Omega_b=0.015-0.019 for H_0=100 (or 0.040-0.051 for H_0=50). Expressed as the baryon to photon ratio, eta, this corresponds to eta=4.0-5.2x10^{-10} (H_0=100) and is in the mid-range of values from other methods. The individual clusters have a dispersion about the mean Omega_{gas} of 40%, and the chi^2 of the 14 clusters is consistent with the hypothesis that the gas-to-light ratio is a universal constant. If we ignore the light of the cD, the variance increases by a factor of three. After the radial segregation of gas and light within a cluster is taken into account, these statistics indicate that there is little variation of the gas-to-light ratio from cluster to cluster over the 0.2 to 0.55 range in redshift.
Chemical freeze-out in heavy ion collisions at large baryon densities
Stefan Floerchinger; Christof Wetterich
2012-08-17
We argue that the chemical freeze-out in heavy ion collisions at high baryon density is not associated to a phase transition or rapid crossover. We employ the linear nucleon-meson model with parameters fixed by the zero-temperature properties of nuclear matter close to the liquid-gas quantum phase transition. For the parameter region of interest this yields a reliable picture of the thermodynamic and chiral properties at non-zero temperature. The chemical freeze-out observed in low-energy experiments occurs when baryon densities fall below a critical value of about 15 percent of nuclear density. This region in the phase diagram is far away from any phase transition or rapid crossover.
Hadronization effects on the baryon-strangeness correlation in quark combination models
Feng-lan Shao; Jun Song; Rui-qin Wang
2015-05-12
The baryon-strangeness correlation in the hadronization of the quark matter is studied within the quark combination mechanism. We calculate the correlation coefficient $C_{BS} = -3\\big(\\langle B S \\rangle -\\langle B\\rangle \\langle S\\rangle\\big)/\\big( \\langle S^2 \\rangle-\\langle S \\rangle^2 \\big)$ of initial hadrons produced from the deconfined free quark system with $C^{(q)}_{BS}=1$. The competition of the production of baryons against that of mesons is the key dynamics that is most relevant to the change of baryon-strangeness correlation during system hadronization. Results of quark combination under the Poisson statistics agree with the statistical model predictions for a hadron resonance gas at vanishing chemical potential but differ from those at relatively large chemical potentials. Results beyond Poisson statistics are also obtained and are compared with calculations of Lattice QCD in the phase boundary, giving the best agreement at temperature $T =163$ MeV. We predict the dependence of the $C_{BS}$ of hadron system on the baryon chemical potential and strangeness. These predictions are expected to be tested by the future Lattice QCD calculations at non-zero chemical potentials and/or by the Beam Energy Scan experiment of STAR Collaboration at RHIC.
Spectroscopy of doubly and triply-charmed baryons from lattice QCD
Padmanath, M. [Tata Institute; Edwards, Robert G. [JLAB; Mathur, Nilmani [Tata Institute; Peardon, Michael [Trinity College, Dublin
2013-11-01
We present the ground and excited state spectra of doubly and triply-charmed baryons by using lattice QCD with dynamical clover fermions. A large set of baryonic operators that respect the symmetries of the lattice and are obtained after subduction from their continuum analogues are utilized. Using novel computational techniques correlation functions of these operators are generated and the variational method is exploited to extract excited states. The lattice spectra that we obtain have baryonic states with well-defined total spins up to 7/2 and the low lying states remarkably resemble the expectations of quantum numbers from SU(6) ? O(3) symmetry. Various energy splittings between the extracted states, including splittings due to hyperfine as well as spin-orbit coupling, are considered and those are also compared against similar energy splittings at other quark masses. Using those splittings for doubly-charmed baryons, and taking input of experimental Bc meson mass, we predict the mass splittings of B?c?Bc to be about 80 ± 8 MeV and m?ccb=8050±10 MeV.
Measurement of charm meson lifetimes
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Davis, Robin E. P.; Kravchenko, I.; Kwak, Nowhan; Zhao, L.
1999-06-01
We report measurements of the D-0, D-,(+) and D-s(+) meson lifetimes using 3.7 fb(-1) of e(+)e(-) annihilation data collected near the Y(4S) resonance with the CLEO detector. The measured lifetimes of the D-0, D+, and D-s(+) mesons are 408.5 +/- 4.1(-3.4)(+3.5...
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 mesons: status and future
Eberhard Klempt
2007-11-22
The evidence for the existence of mesons with exotic quantum numbers and of hybrid candidates with non-exotic quantum numbers is critically reviewed, including candidates with hidden charm. Aims and methods of future searches for hybrid mesons are briefly discussed.
Suppression of Non-photonic Electrons from Enhancement of Charm Baryons in Heavy Ion Collisions
P. R. Sorensen; X. Dong
2006-02-06
At intermediate transverse momentum (2 electrons less frequently than charm meson decays, the non-photonic electron spectrum is sensitive to the Lambda_c/D ratio. In this report we study the dependence of the non-photonic electron spectrum on the baryon-to-meson ratio for charm hadrons. As an example, we take the Lambda_c/D ratio to have the same form as the Lambda/K^0_S ratio. In this case, even if the total charm quark yield in Au+Au collisions scales with the number of binary nucleon-nucleon collisions (N_bin), the electron spectrum at 2 < p_T < 5 GeV/c is suppressed relative to N_bin scaled p+p collisions by as much as 20%.
Partial decay widths of negative parity baryons in the 1/N{sub c} expansion
Gonzalez de Urreta, E. J.; Scoccola, N. N.; Jayalath, C. P.; Goity, J. L.
2013-03-25
The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.
Negative parity baryon decays in the 1/N{sub c} expansion
Jayalath, C.; Goity, J. L.; Gonzalez de Urreta, E.; Scoccola, N. N.
2011-10-01
The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are obtained.
Partial Decay Widths of Negative Parity Baryons in the 1/N{sub c} Expansion
Gonzalez de Urreta, Emiliano; Scoccola, Norberto; Jayalath, Chandala; Goity, Jose
2013-04-01
The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.
RESOLVING THE BARYON-FRACTION PROFILE IN LENSING GALAXIES
Leier, Dominik; Ferreras, Ignacio; Saha, Prasenjit; Falco, Emilio E.
2011-10-20
The study of the distribution of baryonic matter within dark halos enriches our understanding of galaxy formation. We show the radial dependence of stellar baryon-fraction curves derived for 21 lensing galaxies from the CfA-Arizona Space Telescope LEns Survey (CASTLES) by means of stellar population synthesis and pixel-based mass reconstruction. The sample covers a stellar mass range of M{sub s} {approx_equal} 2 x 10{sup 9}-3 x 10{sup 11} M{sub sun} (solar masses) which corresponds to a total enclosed mass range of M{sub L} {approx_equal} 7 x 10{sup 9}-3 x 10{sup 12} M{sub sun} on radial scales from 0.25R{sub e} to 5R{sub e} (effective radii). By examining the M{sub s} and M{sub L} dependence on radial distance to the center of each galaxy, we find that there are pairs of lenses on small to intermediate mass scales which approach at large radii the same values for their enclosed total mass but exhibit very different stellar masses and stellar baryon fractions. This peculiar behavior subsides for the most massive lensing galaxies. All the baryon-fraction profiles show that the dark matter halo overtakes the stellar content between 1.5 and 2.5R{sub e}. At 3R{sub e} most of the stellar component is enclosed. We find evidence for a stellar baryon fraction steadily declining over the full mass range. Furthermore, we shed light on the Fundamental Plane puzzle by showing that the slope of the M{sub L} (< R)-to-M{sub s} (< R) relation approaches the mass-to-light relation of recent Fundamental Plane studies at large radii. We also introduce novel concentration indices c = R90/R50 for stellar and total mass profiles (i.e., the ratio of radii enclosing 90% and 50% of the stellar or total mass). We show that the value c = 2.6 originally determined by light profiles which separates early-type galaxies from late-type galaxies also holds for stellar mass. In particular, less massive dark matter halos turn out to be influenced by the distribution of stellar matter on resolved scales below 10 kpc. The ongoing study of resolved baryon-fraction profiles will make it possible to evaluate the validity of star formation models as well as adiabatic contraction prescriptions commonly used in simulations.
Baryon Spectrum from Superconformal Quantum Mechanics and its...
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Baryon Spectrum from Superconformal Quantum Mechanics and its Light-Front Holographic Embedding Citation Details In-Document Search Title: Baryon Spectrum from Superconformal...
Baryon Spectrum from Superconformal Quantum Mechanics and its...
Office of Scientific and Technical Information (OSTI)
Journal Article: Baryon Spectrum from Superconformal Quantum Mechanics and its Light-Front Holographic Embedding Citation Details In-Document Search Title: Baryon Spectrum from...
Pathways to Rare Baryonic B Decays
Wei-Shu Hou; A. Soni
2000-08-09
We point out new ways to search for charmless baryonic B decays: baryon pair production in association with $\\eta^\\prime$ is very likely as large as or even a bit larger than two body $K\\pi/\\pi\\pi$ modes. We extend our argument, in weaker form, to $B\\to \\gamma + X_s$ and $\\ell\
Baryon Fluctuations in High Energy Nuclear Collisions
Sean Gavin; Claude Pruneau
1999-07-09
We propose that dramatic changes in the variances and covariance of protons and antiprotons can result if baryons approach chemical equilibrium in nuclear collisions at RHIC. To explore how equilibration alters these fluctuations, we formulate both equilibrium and nonequilibrium hadrochemical descriptions of baryon evolution. Contributions to fluctuations from impact parameter averaging and finite acceptance in nuclear collisions are numerically simulated.
Introduction The CLAS Excited Baryon Program
Credé, Volker
Conference Montpellier, 07/08/2008 V. Credé Overview of CLAS Physics #12;Introduction The CLAS Excited Baryon Program The CLAS Polarization Program Summary and Outlook Outline 1 Introduction Physics with the CLAS. Credé Overview of CLAS Physics #12;Introduction The CLAS Excited Baryon Program The CLAS Polarization
A Scenario of Heavy Baryonic Dark Matter
Huo, Ran; Tsai, Yue-Lin Sming; Yanagida, Tsutomu T
2015-01-01
We consider a general class of models in which dark matter is a composite baryonic and antibaryonic particle of some hidden vector-like strong gauge theory. The model building provides simple answers to two basic questions: Annihilation between dark baryon and antibaryon saturates the unitarity bound, which in thermal freeze out predicts the scale of dark matter particle to be about 150 TeV. And the dark matter stability is a result of the accidental dark baryon number, which can still be violated by operators suppressed by large scales, leading to tiny decay rate. We show that annihilation between dark baryon and anti-baryon seems difficult to be detected in the galaxy center in the near future. On the other hand in the minimal model of $SU(3)$ hidden strong gauge group with a Planck scale suppression, the dark matter life time happens to be marginal to the current detection bound, and can explain the current AMS-02 antiproton results.
Baryon Destruction by Asymmetric Dark Matter
Hooman Davoudiasl; David E. Morrissey; Kris Sigurdson; Sean Tulin
2011-06-21
We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause {\\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10^{29}-10^{32} years in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter--induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.
Baryon Destruction by Asymmetric Dark Matter
Davoudiasl, Hooman; Sigurdson, Kris; Tulin, Sean
2011-01-01
We investigate new and unusual signals that arise in theories where dark matter is asymmetric and carries a net antibaryon number, as may occur when the dark matter abundance is linked to the baryon abundance. Antibaryonic dark matter can cause {\\it induced nucleon decay} by annihilating visible baryons through inelastic scattering. These processes lead to an effective nucleon lifetime of 10^{29}-10^{32} years in terrestrial nucleon decay experiments, if baryon number transfer between visible and dark sectors arises through new physics at the weak scale. The possibility of induced nucleon decay motivates a novel approach for direct detection of cosmic dark matter in nucleon decay experiments. Monojet searches (and related signatures) at hadron colliders also provide a complementary probe of weak-scale dark-matter--induced baryon number violation. Finally, we discuss the effects of baryon-destroying dark matter on stellar systems and show that it can be consistent with existing observations.
Costa, R. S.; Cortes, M. R.; Nunes, D. R.; Batista, A. S. A.
2014-11-11
In this work in contrast to the usual Walecka model [1] we include the interaction between the ? – ? mesons [2,3] with the aim of studying the nuclear matter properties in the relativistic mean-field theory in the regime of high temperatures. Therefore in our work we use the non-linear Walecka model. We investigate whether the phase transition characteristic of other models without these interactions vanishes for a given value of chemical potential ? and baryon density ?{sub N}.
Hadronic scattering of charmed mesons
Lin, ZW; Ko, Che Ming; Zhang, B.
2000-01-01
of both charm meson pairs and dileptons resulting from their decays. These effects are estimated for heavy ion collisions at Super Proton Synchrotron energies and are found to be significant....
Does one observe chiral symmetry restoration in baryon spectrum?
T. D. Cohen; L. Ya. Glozman
2002-01-25
It has recently been suggested that the parity doublet structure seen in the spectrum of highly excited baryons may be due to effective chiral symmetry restoration for these states. We review the recent developments in this field. We demonstrate with a simple quantum-mechanical example that it is a very natural property of quantum systems that a symmetry breaking effect which is important for the low-lying spectrum of the system, can become unimportant for the highly-lying states; the highly lying states reveal a multiplet structure of nearly degenerate states. Using the well established concepts of quark-hadron duality, asymptotic freedom in QCD and validity of the operator product expansion in QCD we show that the spectral densities obtained with the local currents that are connected to each other via chiral transformations, very high in the spectrum must coincide. Hence effects of spontaneous breaking of chiral symmetry in QCD vacuum that are crucially important for the low-lying spectra, become irrelevant for the highly-lying states. Then to the extent that identifiable hadronic resonances still exist in the continuum spectrum at high excitations this implies that the highly excited hadrons must fall into multiplets associated with the representations of the chiral group. We demonstrate that this is indeed the case for meson spectra in the large $N_c$ limit. All possible parity-chiral multiplets are classified for baryons and it is demonstrated that the existing data on highly excited $N$ and $\\Delta$ states at masses of 2 GeV and higher is consistent with approximate chiral symmetry restoration. However new experimental studies are needed to achieve any definitive conclusions.
Comment on "Mixing and Decay Constants of Pseudoscalar Mesons"
Kirchbach, M
1999-01-01
The key assumption used recently by Feldmann, Kroll and Stich [Phys.Rev. D58, 114006 (1998)] that the decay constants f_\\eta, and f_\\eta ' of the respective eta and eta ' mesons in the quark flavor basis follow the pattern of strange and non--strange quarkonia mixing in their wave functions, is reproduced in identifying the non-isotriplet part of the strong neutral axial current with the genuine axial hypercharge current J_{\\mu, 5}^Y =\\bar q \\gamma_\\mu\\gamma_5 Y/2 q, where Y=C+S+B is defined by the Gell-Mann-Nakano-Nishijima relation as the sum of charm (C), strangeness (S), and baryon (B) quark quantum numbers. The inequivalence between octet and hypercharge axial currents is pointed out.
Low-lying $?$ Baryons with spin 1/2 in Two-flavor Lattice QCD
Toru T. Takahashi; Makoto Oka
2010-02-10
Low-lying $\\Lambda$ baryons with spin 1/2 are analyzed in full (unquenched) lattice QCD. We construct $2 \\times 2$ cross correlators from flavor SU(3) "octet" and "singlet" baryon operators, and diagonalize them so as to extract information of two low-lying states for each parity. The two-flavor CP-PACS gauge configurations are used, which are generated in the renormalization-group improved gauge action and the ${\\mathcal O}(a)$-improved quark action. Three different $\\beta$'s, $\\beta = 1.80$, 1.95 and 2.10, are employed, whose corresponding lattice spacings are $a = 0.2150$, 0.1555 and 0.1076 fm. For each cutoff, we use four hopping parameters, ($\\kappa_{\\rm val}, \\kappa_{\\rm sea}$), which correspond to the pion masses ranging about from 500 MeV to 1.1 GeV. Results indicate that there are two negative-parity $\\Lambda$ states nearly degenerate at around 1.6 GeV, while no state as low as $\\Lambda (1405)$ is observed. By decomposing the flavor components of each state, we find that the lowest (1st-excited) negative-parity state is dominated by flavor-singlet (flavor-octet) component. We also discuss meson-baryon components of each state, which has drawn considerable attention in the context of multi-quark pictures of $\\Lambda (1405)$.
Nucleon Resonance Electrocouplings from the CLAS Meson Electroproduction Data.
Inna Aznauryan, Volker Burkert, Viktor Mokeev
2012-04-01
Transition helicity amplitudes {gamma}{sub {nu}}NN* (electrocouplings) were determined for prominent excited proton states with masses less than 1.8 GeV in independent analyses of major meson electroproduction channels: {pi}{sup +}n, {pi}{sup 0}p and {pi}{sup +}{pi}{sup -}p. Consistent results on resonance electrocouplings obtained from analyses of these exclusive reactions with very different non-resonant contributions demonstrated reliable extraction of these fundamental quantities for states that have significant decays for either N{pi} or N{pi}{pi} channels. Preliminary results on electrocouplings of N* states with masses above 1.6 GeV have become available from the CLAS data on {pi}{sup +}{pi}{sup -}p electroproduction off protons for the first time. Comparison with quark models and coupled channel approaches strongly suggest that N* structure is determined by contributions from an internal core of three constituent quarks and an external meson-baryon cloud at the distance scales covered in measurements with the CLAS detector.
Baryon Number as the Fourth Color
Fornal, Bartosz; Tait, Tim M P
2015-01-01
We propose an extension of the Standard Model in which baryon number is promoted to be part of a non-Abelian gauge symmetry at high energies. Specifically, we consider the gauge group SU(4) x SU(2)_L x U(1)_X, where the SU(4) unifies baryon number and color. This symmetry is spontaneously broken down to the Standard Model gauge group at a scale which can be as low as a few TeV. The SU(4) structure implies that each SM quark comes along with an uncolored quark partner, the lightest of which is stabilized by the generalized baryon number symmetry and can play the role of dark matter. We explore circumstances under which one can realize a model of asymmetric dark matter whose relic abundance is connected to the observed baryon asymmetry, and discuss unique signatures that can be searched for at the LHC.
Baryon Dissociation in a Strongly Coupled Plasma
Chethan Krishnan
2008-11-14
Using the dual string theory, we study a circular baryonic configuration in a wind of strongly coupled N=4 Yang-Mills plasma blowing in the plane of the baryon, before and after a quark has dissociated from it. A simple enough model that captures many interesting features is when there are four quarks in the baryon. As a step towards phenomenology, we compare representative dissociated configurations, and make some comments about their energetics and other properties. Related results that we find include the observation that the screening length formula L_s T ~ (1-v^2)^{1/4} obtained previously for other color singlet configurations, is robust for circular baryons as well.
Warm-hot baryons comprise 5-10 per cent of filaments in the cosmic web
Eckert, Dominique; Shan, HuanYuan; Kneib, Jean-Paul; Erben, Thomas; Israel, Holger; Jullo, Eric; Klein, Matthias; Massey, Richard; Richard, Johan; Tchernin, Celine
2015-01-01
Observations of the cosmic microwave background indicate that baryons account for 5% of the Universe's total energy content. In the local Universe, the census of all observed baryons falls short of this estimate by a factor of two. Cosmological simulations indicate that the missing baryons might not have condensed into virialized haloes, but reside throughout the filaments of the cosmic web (where matter density is larger than average) as a low-density plasma at temperatures of $10^5-10^7$ kelvin, known as the warm-hot intergalactic medium. There have been previous claims of the detection of warm baryons along the line of sight to distant blazars and of hot gas between interacting clusters. These observations were, however, unable to trace the large-scale filamentary structure, or to estimate the total amount of warm baryons in a representative volume of the Universe. Here we report X-ray observations of filamentary structures of gas at $10^7$ kelvin associated with the galaxy cluster Abell 2744. Previous obs...
SIMULATIONS OF EARLY BARYONIC STRUCTURE FORMATION WITH STREAM VELOCITY. II. THE GAS FRACTION
Naoz, Smadar [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yoshida, Naoki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)] [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Gnedin, Nickolay Y., E-mail: snaoz@cfa.harvard.edu [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)
2013-01-20
Understanding the gas content of high-redshift halos is crucial for studying the formation of the first generation of galaxies and reionization. Recently, Tseliakhovich and Hirata showed that the relative 'stream' velocity between the dark matter and baryons at the time of recombination-formally a second-order effect, but an unusually large one-can influence the later structure formation history of the universe. We quantify the effect of the stream velocity on the so-called characteristic mass-the minimum mass of a dark matter halo capable of retaining most of its baryons throughout its formation epoch-using three different high-resolution sets of cosmological simulations (with separate transfer functions for baryons and dark matter) that vary in box size, particle number, and the value of the relative velocity between the dark matter and baryons. In order to understand this effect theoretically, we generalize the linear theory filtering mass to properly account for the difference between the dark matter and baryonic density fluctuation evolution induced by the stream velocity. We show that the new filtering mass provides an accurate estimate for the characteristic mass, while other theoretical ansatzes for the characteristic mass are substantially less precise.
Experimental Investigation of Weak Non-Mesonic Decay of 10Be(Lambda)Hypernuclei at CEBAF
S. Majewski; L. Majling; A. Margaryan; L. Tang
2005-08-05
Hypernuclei are convenient laboratory to study the baryon-baryon weak interaction and associated effective Hamiltonian. The strangeness changing process, in which a Lambda hyperon converts to a neutron with a release up to 176 MeV, provides a clear signal for a conversion of an s-quark to a d-quark. We propose to perform a non-mesonic weak decay study of 10Be(Lambda)hypernuclei using the (e,eK) reaction. These investigations will fully utilize the unique parameters of the CEBAF CW electron beam and RF system and are enabled by (1) the use of new detector for alpha particles based on the recently developed RF timing technique with picosecond resolution and (2) the small angle and large acceptance kaon spectrometer-HKS in Hall C.
McCracken, Michael E.
2015-10-09
We present a search for ten baryon-number violating decay modes of $\\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state ($\\Lambda \\rightarrow m \\ell$) and conserve either the sum or the difference of baryon and lepton number ($B \\pm L$). The tenth decay mode ($\\Lambda \\rightarrow \\bar{p}\\pi^+$) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range $(4-200)\\times 10^{-7}$ at the $90\\%$ confidence level.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
McCracken, Michael E.
2015-10-09
We present a search for ten baryon-number violating decay modes of $\\Lambda$ hyperons using the CLAS detector at Jefferson Laboratory. Nine of these decay modes result in a single meson and single lepton in the final state ($\\Lambda \\rightarrow m \\ell$) and conserve either the sum or the difference of baryon and lepton number ($B \\pm L$). The tenth decay mode ($\\Lambda \\rightarrow \\bar{p}\\pi^+$) represents a difference in baryon number of two units and no difference in lepton number. We observe no significant signal and set upper limits on the branching fractions of these reactions in the range $(4-200)\\times 10^{-7}$more »at the $90\\%$ confidence level.« less
Baryonic matter perturbations in decaying vacuum cosmology
Marttens, R.F. vom; Zimdahl, W.; Hipólito-Ricaldi, W.S. E-mail: wiliam.ricaldi@ufes.br
2014-08-01
We consider the perturbation dynamics for the cosmic baryon fluid and determine the corresponding power spectrum for a ?(t)CDM model in which a cosmological term decays into dark matter linearly with the Hubble rate. The model is tested by a joint analysis of data from supernovae of type Ia (SNIa) (Constitution and Union 2.1), baryonic acoustic oscillations (BAO), the position of the first peak of the anisotropy spectrum of the cosmic microwave background (CMB) and large-scale-structure (LSS) data (SDSS DR7). While the homogeneous and isotropic background dynamics is only marginally influenced by the baryons, there are modifications on the perturbative level if a separately conserved baryon fluid is included. Considering the present baryon fraction as a free parameter, we reproduce the observed abundance of the order of 5% independently of the dark-matter abundance which is of the order of 32% for this model. Generally, the concordance between background and perturbation dynamics is improved if baryons are explicitly taken into account.
Photoproduction of mesons off nuclei
B. Krusche
2011-10-02
Recent results for the photoproduction of mesons off nuclei are reviewed. These experiments have been performed for two major lines of research related to the properties of the strong interaction. The investigation of nucleon resonances requires light nuclei as targets for the extraction of the isospin composition of the electromagnetic excitations. This is done with quasi-free meson photoproduction off the bound neutron and supplemented with the measurement of coherent photoproduction reactions, serving as spin and/or isospin filters. Furthermore, photoproduction from light and heavy nuclei is a very efficient tool for the study of the interactions of mesons with nuclear matter and the in-medium properties of hadrons. Experiments are currently rapidly developing due to the combination of high quality tagged (and polarized) photon beams with state-of-the-art 4pi detectors and polarized targets.
The Baryonic Tully Fisher Relation
Sebastian Gurovich; Stacy S. McGaugh; Ken C. Freeman; Helmut Jerjen; Lister Staveley-Smith; W. J. G. De Blok
2004-11-17
We validate the baryonic Tully Fisher (BTF) relation by exploring the Tully Fish er (TF) and BTF properties of optically and HI-selected disk galaxies. The data includes galaxies from: Sakai et al. (2000) calibrator sample; McGaugh et al. (2000: MC2000) I-band sample; and 18 newly acquired HI-selected field dwarf galaxies observed with the ANU 2.3m telescope and the ATNF Parkes telescope from Gurovich's thesis sample (2005). As in MC2000, we re-cast the TF and BTF relations as relationships between baryo n mass and W_{20}. First we report some numerical errors in MC2000. Then, we c alculate weighted bi-variate linear fits to the data, and finally we compare the fits of the intrinsically fainter dwarfs with the brighter galaxies of Sakai et al. (2000). With regards to the local calibrator disk galaxies of Sakai et al. (2000), our results suggest that the BTF relation is indeed tighter than the T F relation and that the slopes of the BTF relations are statistically flatter th an the equivalent TF relations. Further, for the fainter galaxies which include the I-band MCG2000 and HI-selected galaxies of Gurovich's thesis sample, we calc ulate a break from a simple power law model because of what appears to be real c osmic scatter. Not withstanding this point, the BTF models are marginally better models than the equivalent TF ones with slightly smaller reduced chi^2.
Philipp Wein; Andreas Schäfer
2015-01-28
In this work we present a minimal parametrization of the light-cone distribution amplitudes of the baryon octet including higher twist contributions. Simultaneously we obtain the quark mass dependence of the amplitudes at leading one-loop accuracy by the use of three-flavor baryon chiral perturbation theory (BChPT), which automatically yields model-independent results for the leading $SU(3)$ flavor breaking effects. For that purpose we have constructed the nonlocal light-cone three-quark operators in terms of baryon octet and meson fields and have carried out a next-to-leading order BChPT calculation. We were able to find a minimal set of distribution amplitudes (DAs) that do not mix under chiral extrapolation towards the physical point and naturally embed the $\\Lambda$ baryon. Additionally they are chosen in such a way that all DAs of a certain symmetry class have a similar quark mass dependence (independent of the twist of the corresponding amplitude), which allows for a compact presentation. The results are well-suited for the extrapolation of lattice data and for model building.
Decoherence free Bd and Bs meson systems
Ashutosh Kumar Alok; Subhashish Banerjee
2013-04-15
We study the impact of decoherence on B meson systems with specific emphasis on Bs. For consistency we also study the Bd mesons based on the most recent data. We find that the Bd mesons are 34 sigma away from total decoherence, while the Bs mesons are seen to be upto 31sigma away from total decoherence. Thus, our results prove, with experimental verity, that neutral meson systems are free from decoherence effects. Therefore, this provides a very useful laboratory for testing the foundations of quantum mechanics.
High Statistics Analysis using Anisotropic Clover Lattices: (II) Three-Baryon Systems
Silas R. Beane; William Detmold; Thomas C Luu; Kostas Orginos; Assumpta Parreno; Martin J. Savage; Aaron Torok; Andre Walker-Loud
2009-05-04
We present the results of an exploratory Lattice QCD calculation of three-baryon systems through a high-statistics study of one ensemble of anisotropic clover gauge-field configurations with a pion mass of m_\\pi ~ 390 MeV. Because of the computational cost of the necessary contractions, we focus on correlation functions generated by interpolating-operators with the quantum numbers of the $\\Xi^0\\Xi^0 n$ system, one of the least demanding three baryon systems in terms of the number of contractions. We find that the ground state of this system has an energy of E_{\\Xi^0\\Xi^0n}= 3877.9\\pm 6.9\\pm 9.2\\pm3.3 MeV corresponding to an energy-shift due to interactions of \\delta E_{\\Xi^0\\Xi^0n}=E_{\\Xi^0\\Xi^0n}-2M_{\\Xi^0} -M_n=4.6\\pm 5.0\\pm 7.9\\pm 4.2 MeV. There are a significant number of time-slices in the three-baryon correlation function for which the signal-to-noise ratio is only slowly degrading with time. This is in contrast to the exponential degradation of the signal-to-noise ratio that is observed at larger times, and is due to the suppressed overlap of the source and sink interpolating-operators that are associated with the variance of the three-baryon correlation function onto the lightest eigenstates in the lattice volume (mesonic systems). As one of the motivations for this area of exploration is the calculation of the structure and reactions of light nuclei, we also present initial results for a system with the quantum numbers of the triton (pnn). This present work establishes a path to multi-baryon systems, and shows that Lattice QCD calculations of the properties and interactions of systems containing four and five baryons are now within sight.
Distribution Amplitudes of Pseudoscalar Mesons
V. M. Braun; M. Gockeler; R. Horsley; H. Perlt; D. Pleiter; P. E. L. Rakow; G. Schierholz; A. Schiller; W. Schroers; H. Stueben; J. M. Zanotti
2006-10-09
We present results for the first two moments of the distribution amplitudes of pseudoscalar mesons. Using two flavors of non-perturbatively improved clover fermions and non-perturbative renormalization of the matrix elements we perform both chiral and continuum extrapolations and compare with recent results from models and experiments.
Distribution Amplitudes of Vector Mesons
V. M. Braun; D. Brömmel; M. Göckeler; R. Horsley; Y. Nakamura; H. Perlt; D. Pleiter; P. E. L. Rakow; A. Schäfer; G. Schierholz; A. Schiller; W. Schroers; T. Streuer; H. Stüben; J. M. Zanotti
2007-11-14
Results are presented for the lowest moment of the distribution amplitude for the K-star vector meson. Both longitudinal and transverse moments are investigated. We use two flavours of O(a) improved Wilson fermions, together with a non-perturbative renormalisation of the matrix element.
A Roadmap For Meson Spectroscopy
M. G. Olsson
2002-07-31
An efficient classification of light quark meson states is discussed based on the dominance of angular and radial quark excitation. A synthesis of Regge and quark dynamics allows a natural unification of light quark-antiquark spectroscopies and indicates the states that fall outside this category such as molecules, hybrids, and glueballs.
Energy and system size dependence of ?meson production in Cu+Cu and Au+Au collisions
STAR Collaboration
2008-10-28
We study the beam-energy and system-size dependence of \\phi meson production (using the hadronic decay mode \\phi -- K+K-) by comparing the new results from Cu+Cu collisions and previously reported Au+Au collisions at \\sqrt{s_NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from mid-rapidity (|y|energy, the transverse momentum distributions for \\phi mesons are observed to be similar in yield and shape for Cu+Cu and Au+Au colliding systems with similar average numbers of participating nucleons. The \\phi meson yields in nucleus-nucleus collisions, normalised by the average number of participating nucleons, are found to be enhanced relative to those from p+p collisions with a different trend compared to strange baryons. The enhancement for \\phi mesons is observed to be higher at \\sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations for the produced \\phi(s\\bar{s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.
Rougemont, Romulo
2015-01-01
Five dimensional black hole solutions that describe the QCD crossover transition seen in (2+1)-flavor lattice QCD calculations at nonzero baryon densities are used to obtain predictions for the baryon susceptibility, baryon conductivity, baryon diffusion constant, and thermal conductivity of the strongly coupled quark-gluon plasma in the range of temperatures $T=130-300$ MeV and baryon chemical potentials $\\mu_B=0-400$ MeV. Diffusive transport is predicted to be already suppressed in this region of the QCD phase diagram in a way that is consistent with the existence of a critical end point at larger baryon densities.
Dark Matter and the Baryon Asymmetry
Glennys R. Farrar; Gabrijela Zaharijas
2005-10-06
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds.
Heavy baryons in the large Nc limit
Albertus, C; Fernando, I P; Goity, J L
2015-01-01
It is shown that in the large Nc limit heavy baryon masses can be estimated quantitatively in a 1/Nc expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of Nc. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. The results provide good estimates for the first sub-leading in 1/Nc corrections.
Heavy baryons in the large Nc limit
C. Albertus; E. Ruiz Arriola; I. P. Fernando; J. L. Goity
2015-07-16
It is shown that in the large Nc limit heavy baryon masses can be estimated quantitatively in a 1/Nc expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of Nc. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. The results provide good estimates for the first sub-leading in 1/Nc corrections.
Study of Charm Baryons with the BaBar Experiment
Brian Aa. Petersen
2006-10-16
We report on several studies of charm baryon production and decays by the BaBar collaboration. We confirm previous observations of the $\\Xi_c^{'0/+}$, $\\Xi_c(2980)^+$ and $\\Xi_c(3077)^+$ baryons, measure branching ratios for Cabibbo-suppressed $\\Lambda_c^+$ decays and use baryon decays to study the properties of the light-quark baryons, $\\Omega^-$ and $\\Xi(1690)^0$.
Study of B Meson Decays to ppbarh Final States
Hryn'ova, Tetiana B.; /SLAC
2006-03-22
B mesons are unique among well-established non-quarkonium mesons in their ability to decay into baryons. Baryonic B decays offer a wide range of interesting areas of study: they can be used to test our theoretical understanding of rare decay processes involving baryons, search for direct CP violation and study low-energy QCD. This thesis presents measurements of branching fractions and a study of the decay dynamics of the charmless three-body decays of B meson into p{bar p}h final states, where h = {pi}{sup +}, K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}. With a sample of 232 million {Upsilon}(4S) {yields} B{bar B} events collected with the BaBar detector, we report the first observation of the B {yields} p{bar p}K*{sup 0} decay, and provide improved measurements of branching fractions of the other modes. The distribution of the three final-state particles is of particular interest since it provides dynamical information on the possible presence of exotic intermediate states such as the hypothetical pentaquark states {Theta}*{sup ++} and {Theta}{sup +}in the m{sub pK{sup +}} and m{sub pK{sub S}{sup 0}} spectra, respectively, or glueball states (such as the tensor glueball f{sub J}(2220)) in the m{sub p{bar p}} spectrum. No evidence for exotic states is found and upper limits on the branching fractions are set. An enhancement at low p{bar p} mass is observed in all the B {yields} p{bar p}h modes, and its shape is compared between the decay modes and with the shape of the time-like proton form factor. A Dalitz plot asymmetry in B {yields} p{bar p}K{sup +} mode suggests dominance of the penguin amplitude in this decay and disfavors the possibility that the low mass p{bar p} enhancement originates from the presence of a resonance below threshold (such as the recently seen baryonium candidate at 1835 MeV/c{sup 2}). We also identify decays of the type B {yields} X{sub c{bar c}}h {yields} p{bar p}h, where h = K{sup +}, K{sub S}{sup 0}, K*{sup 0} or K*{sup +}, and X{sub c{bar c}} = {eta}{sub c} or J/{psi}. In particular, we report on the evidence of the B {yields} {eta}{sub c}K*{sup +} decay and provide a measurement of the width of {eta}{sub c}.
Neutron-antineutron Oscillation and Baryonic Majoron: Low Scale Spontaneous Baryon Violation
Zurab Berezhiani
2015-07-20
We discuss a possibility that baryon number $B$ is spontaneously broken at low scales, of the order of MeV or even smaller, so that the neutron-antineutron oscillation can be induced at the experimentally accessible level. An associated Goldstone particle, baryonic majoron, can have observable effects in neutron to antineutron transitions in nuclei or dense nuclear matter. By extending baryon number to $B-L$ symmetry, baryo-majoron can be identified with the ordinary majoron associated with the spontaneous breaking of lepton number, with interesting implications for neutrinoless $2\\beta$ becay with the majoron emission, etc. We also discuss a hypothesis suggesting that baryon number maybe spontaneously broken by the QCD itself via the six-quark condensates.
Hybrid mesons and auxiliary fields
Fabien Buisseret; Vincent Mathieu
2006-09-29
Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the $\\pi_1(1600)$ and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body $q\\bar q$ system with an excited flux tube, or a three-body $q\\bar q g$ system. We also compute the masses of the $1^{-+}$ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models.
Recent Results on Charmed Baryons with Belle
Tsuboyama, T. [KEK, High Energy Accelerator Research Organization, Tsukuba (Japan)
2006-11-17
The Belle detector has accumulated e+e- collision data corresponding to 600 fb-1 at the {upsilon}(4S) energy. The paper presents the improved measurement of known charmed baryons; {xi}c and {xi}c(2645), as well as observation of new states; {sigma}c(2800), {xi}cx(2980) and {xi}cx(3077)
Low Mass Exotic Baryons: Myth or Reality ?
B. Tatischeff
2002-07-08
Using mainly $\\vec{p}$ p $\\to$ p ${\\pi^+}X$ and $\\vec{p}$ p $\\to$ p$_{f}$~p$_{s}$ X reactions, narrow baryonic structures were observed in the mass range 950$\\le$ M $\\le$ 1800 MeV.
Magnetic structure of $K$ and $?$ mesons
E. V. Luschevskaya; O. E. Solovjeva; O. V. Teryaev
2015-11-30
We explore the energy dependence of $K$ and $\\pi$ mesons off the background constant abelian magnetic field in SU(3) lattice gauge theory without dynamical quarks. The energy of neutral pseudoscalar mesons diminishes with the field, while the energy of charged one increases according with the theoretical expectation. We estimate the magnetic polarizabilities of pseudoscalar $K^0$, $\\pi^0$ and $\\pi^{\\pm}$ mesons for various quark masses. The contribution of the magnetic hyperpolarizability to kaon and pion energies was found also.
Testing a model for the puzzling spin 0 mesons
Joseph Schechter
2012-02-14
After a brief historical discussion of meson quantum numbers, we examin the possibility of additional internal meson structure. Experimental tests of this structure using the semi-leptonic decays of the $D_s^+n$(1968) meson are discussed.
Exotic low mass narrow baryons extracted from charge exchange reactions
B. Tatischeff; E. Tomasi-Gustafsson
2010-02-12
This paper aims to give further evidence for the existence of low mass exotic baryons. Narrow structures in baryonic missing mass or baryonic invariant mass were observed during the last twelve years. Since their evidence is still under debate, various data, measured with incident hadrons, by different collaborations, are reanalyzed to bring evidence on these narrow exotic baryonic resonances excited in charge-exchange reactions. These structures are clearly exotic as there is no room for them in the $qqq$ configurations: their width is smaller than the widths of "classical" baryonic resonances, moreover some of the masses lie below the pion threshold mass.
Experiments on eta-meson production
Peng, J.C.
1985-01-01
Following a review of some highlights of eta-meson characteristics, the status of eta-meson production experiments is reviewed. The physics motivations and first results of two LAMPF experiments on (..pi..,eta) reactions are discussed. Possible future experiments are also discussed. 42 refs., 12 figs., 4 tabs.
Rho Meson in Dense Hadronic Matter
Asakawa, M.; Ko, Che Ming; Levai, P.; Qiu, X. J.
1992-01-01
The spectral function of a rho meson that is at rest in dense hadronic matter and couples strongly to the pion is studied in the vector dominance model by including the effect of the delta-hole polarization on the pion. With the free rho-meson mass...
Exotic hybrid mesons with light quarks
Claude Bernard; Tom Blum; Thomas A. DeGrand; Carleton DeTar; Steven Gottlieb; Urs. M. Heller; Jim Hetrick; Craig McNeile; Kari Rummukainen; Bob Sugar; Doug Toussaint; Matt Wingate
1996-07-12
Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum numbers inaccessible to conventional quark-antiquark states. Confirmation of such states would give information on the role of "dynamical" color in low energy QCD. We present preliminary results for hybrid meson masses using light Wilson valence quarks.
New developments in multi-meson systems
William Detmold; Brian Smigielski
2011-01-13
New developments in the study of multi-meson systems are reviewed. We highlight a new recursive algorithm for generating the requisite contractions needed for studying complex systems of mesons involving large numbers of particles or multiple species of particles. First results on mixed species systems involving pions and kaons are also presented.
Status of Chiral Meson Physics
Johan Bijnens
2014-11-24
This talk includes a short introduction to Chiral Perturbation Theory in the meson sector concentrating on a number of recent developments. I discuss the latest fit of the low-energy constants. Finite volume corrections are discussed for the case with twisted boundary conditions for form-factors and first results at two-loops for three flavours for masses. The last part discusses the extension to other symmetry breaking patterns relevant for technicolour and related theories as well as the calculation of leading logarithms to high loop orders.
Two Baryons with Twisted Boundary Conditions
Briceno, Raul; Davoudi, Zohreh; Luu, Thomas; Savage, Martin
2014-04-01
The quantization condition for two particle systems with arbitrary number of two-body open coupled-channels, spin and masses in a finite cubic volume is presented. The condition presented is in agreement with all previous studies of two-body systems in a finite volume. The result is fully relativistic and holds for all momenta below inelastic thresholds and is exact up to exponential volume corrections that are governed by m{sub {pi}} L, where m{sub {pi}} is the pion mass and L is the spatial extent of my box. Its implication for the studies of coupled-channel baryon-baryon systems is discussed, and the necessary tools for implementing the formalism are review.
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
Baryon spin-flavor structure from an analysis of lattice QCD results of the baryon spectrum
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Fernando, I.?P.; Goity, J.?L.
2015-02-01
The excited baryon masses are analyzed in the framework of the 1/Nc expansion using the available physical masses and also the masses obtained in lattice QCD for different quark masses. The baryon states are organized into irreducible representations of SU(6) x O(3), where the [56,lP=0?] ground state and excited baryons, and the [56,2+] and [70}},1-] excited states are analyzed. The analyses are carried out to order O(1/Nc) and first order in the quark masses. The issue of state identifications is discussed. Numerous parameter independent mass relations result at those orders, among them the well known Gell-Mann-Okubo and Equal Spacing relations,more »as well as additional relations involving baryons with different spins. It is observed that such relations are satisfied at the expected level of precision. The main conclusion of the analysis is that qualitatively the dominant physical effects are similar for the physical and the lattice QCD baryons.« less
Charmed bottom baryon spectroscopy from lattice QCD
Brown, Zachary S.; Detmold, William; Meinel, Stefan; Orginos, Kostas
2014-11-01
We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with JP = 1/2^{+} and JP = 3/2^{+}. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass using SU(4|2) heavy-hadron chiral perturbation theory including 1/m_{Q} and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.
Charmed bottom baryon spectroscopy from lattice QCD
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Brown, Zachary S.; Detmold, William; Meinel, Stefan; Orginos, Kostas
2014-11-01
We calculate the masses of baryons containing one, two, or three heavy quarks using lattice QCD. We consider all possible combinations of charm and bottom quarks, and compute a total of 36 different states with JP = 1/2+ and JP = 3/2+. We use domain-wall fermions for the up, down, and strange quarks, a relativistic heavy-quark action for the charm quarks, and nonrelativistic QCD for the bottom quarks. Our analysis includes results from two different lattice spacings and seven different pion masses. We perform extrapolations of the baryon masses to the continuum limit and to the physical pion mass usingmore »SU(4|2) heavy-hadron chiral perturbation theory including 1/mQ and finite-volume effects. For the 14 singly heavy baryons that have already been observed, our results agree with the experimental values within the uncertainties. We compare our predictions for the hitherto unobserved states with other lattice calculations and quark-model studies.« less
Baryonic pinching of galactic dark matter halos
Gustafsson, Michael; Fairbairn, Malcolm; Sommer-Larsen, Jesper [Cosmology, Particle Astrophysics and String Theory, Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91, Stockholm (Sweden); Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)
2006-12-15
High resolution cosmological N-body simulations of four galaxy-scale dark matter halos are compared to corresponding N-body/hydrodynamical simulations containing dark matter, stars and gas. The simulations without baryons share features with others described in the literature in that the dark matter density slope continuously decreases towards the center, with a density {rho}{sub DM}{proportional_to}r{sup -1.3{+-}}{sup 0.2}, at about 1% of the virial radius for our Milky Way sized galaxies. The central cusps in the simulations which also contain baryons steepen significantly, to {rho}{sub DM}{proportional_to}r{sup -1.9{+-}}{sup 0.2}, with an indication of the inner logarithmic slope converging. Models of adiabatic contraction of dark matter halos due to the central buildup of stellar/gaseous galaxies are examined. The simplest and most commonly used model, by Blumenthal et al., is shown to overestimate the central dark matter density considerably. A modified model proposed by Gnedin et al. is tested and it is shown that, while it is a considerable improvement, it is not perfect. Moreover, it is found that the contraction parameters in their model not only depend on the orbital structure of the dark-matter-only halos but also on the stellar feedback prescription which is most relevant for the baryonic distribution. Implications for dark matter annihilation at the galactic center are discussed and it is found that, although our simulations show a considerable reduced dark matter halo contraction as compared to the Blumenthal et al. model, the fluxes from dark matter annihilation are still expected to be enhanced by at least a factor of a hundred, as compared to dark-matter-only halos. Finally, it is shown that, while dark-matter-only halos are typically prolate, the dark matter halos containing baryons are mildly oblate with minor-to-major axis ratios of c/a=0.73{+-}0.11, with their flattening aligned with the central baryonic disks.
Introduction and Motivation Experimental Methods in Meson Spectroscopy
Credé, Volker
Introduction and Motivation Experimental Methods in Meson Spectroscopy Glueballs and Light Mesons, Italy 03/15/2010 V. Credé Glueballs and Light-Meson Spectroscopy #12;Introduction and Motivation Summary and Outlook Outline 1 Introduction and Motivation The Quark Model of Hadrons Meson Spectroscopy 2
GlueX: Meson Spectroscopy in Photoproduction
Salgado, Carlos [Norfolk State University, JLAB; Smith, Elton S. [JLAB
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.
Light Baryons from 2+1 flavor DWF QCD
C. M. Maynard; RBC; UKQCD collaborations
2010-01-28
We present results from the RBC and UKQCD collaboration ensembles of 2+1 flavor DWF QCD for the light baryon spectrum.
Precision Cosmology and the Density of Baryons in the Universe
M. Kaplinghat; M. S. Turner
2000-11-14
Big-bang Nucleosynthesis (BBN) and Cosmic Microwave Background (CMB) anisotropy measurements give independent, accurate measurements of the baryon density and can test the framework of the standard cosmology. Early CMB data are consistent with the longstanding conclusion from BBN that baryons constitute a small fraction of matter in the Universe, but may indicate a slightly higher value for the baryon density. We clarify precisely what the two methods determine, and point out that differing values for the baryon density can indicate either an inconsistency or physics beyond the standard models of cosmology and particle physics. We discuss other signatures of the new physics in CMB anisotropy.
Balmer-Like Series for Baryon Resonances
Losanow-Kirchbach, M
1998-01-01
The pole positions of various baryon resonances have been found to reveal a well pronounced clustering, the so-called H"ohler cluster. In a previous work, the H"ohler clusters have been shown to be identical to Lorentz multiplets of the type (1/2+l', 1/2+l')*[(1/2,0)+(0,1/2)] with l' integer. Here we show that the cluster positions are well described by means of a Balmer-series like recursive mass formula.
The three-baryon $?NN$ potential
A. A. Usmani
1995-03-27
Using a three-baryon $\\Lambda NN$ potential having a spin-independent dispersive and a two-pion exchange components, realistic variational Monte Carlo calculations have been performed for the $\\Lambda$-seperation energy for $^{5}_{\\Lambda}$He. A relationship between strengths associated with both pieces of $\\Lambda NN$ force giving exact experimental $\\Lambda$-seperation energy has been obtained which then combined with our previous study on $^{17}_{\\,\\,\\Lambda}$O hypernucleus determines a unique and acceptable set of strength parameters for $\\Lambda NN$ potential. The $\\Lambda NN$ force is found important for the core polarization.
Ad. R. Raduta; F. Gulminelli; M. Oertel
2014-09-15
We study the thermodynamical properties of compressed baryonic matter with strangeness within non-relativistic energy density functional models with a particular emphasis on possible phase transitions found earlier for a simple $n,p,e,\\Lambda$-mixture. The aim of the paper is twofold: I) examining the phase structure of the complete system, including the full baryonic octet and II) testing the sensitivity of the results to the model parameters. We find that, associated to the onset of the different hyperonic families, up to three separate strangeness-driven phase transitions may occur. Consequently, a large fraction of the baryonic density domain is covered by phase coexistence with potential relevance for (proto)-neutron star evolution. It is shown that the presence of a phase transition is compatible both with the observational constraint on the maximal neutron star mass, and with the present experimental information on hypernuclei. In particular we show that two solar mass neutron stars are compatible with important hyperon content. Still, the parameter space is too large to give a definitive conclusion of the possible occurrence of a strangeness driven phase transition, and further constraints from multiple-hyperon nuclei and/or hyperon diffusion data are needed.
Rare meson decays into very light neutralinos
O'Leary, Ben [Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany)
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.
TABLE OF CONTENTS Content Page
Li, Jiuyong "John"
#12;TABLE OF CONTENTS Content Page Version 5.1 iii September 2012 Contents 1 INTRODUCTION 1-1 1;TABLE OF CONTENTS Content Page Version 5.1 iv September 2012 3 PLANNING AND DESIGN GUIDELINES 3-1 3 Noise 3-25 3.3.15 Optimise Light 3-25 3.3.16 Save Water 3-25 3.3.17 Minimise Waste 3-25 3.4 Green Star
Baryons and Low-Density Baryonic Matter in 1+1 Dimensional Large N_c QCD with Heavy Quarks
Prabal Adhikari; Thomas D. Cohen; Arec Jamgochian; Nilay Kumar
2012-12-10
This paper studies baryons and baryonic matter in the combined large N_c and heavy quark mass limits of QCD in 1+1 dimension. In this non-relativistic limit, baryons are composed of N_c quarks that interact, at leading order in N_c, through a color Coulomb potential. Using variational techniques, very accurate calculations of single baryon masses and interaction energies of low-density baryon crystal are performed. These results are used to cross-check a general numerical approach applicable for arbitrary quark masses and baryon densities recently proposed by Bringoltz, which is based on a lattice in a finite box with periodic boundary conditions. The Bringoltz method differs from a previous approach of Salcedo, et al. in its treatment of a finite box effect - namely gauge configurations that wind around the box. One might expect these effects to be small for large enough boxes, in which the baryon density approaches zero to high accuracy at the edges. However, the effects of these windings appear to be quite large even in such boxes. The large mass infinite volume calculations performed here are consistent with the results of numerical calculations using the Bringoltz method. The calculation of the baryon crystal interaction energy requires the assumption that at low-densities the ground state is composed of individual baryons, each in a color-singlet state and orthogonal to each other. This assumption is plausible but ad hoc in that one can construct configurations in which the entire state is color-singlet but cannot be broken into individual color-singlet baryons. The interaction energy of low-density baryon crystals calculated with the assumption is consistent with numerical results based on Bringoltz's approach suggesting that the assumption is justified. This further supports a similar assumption that was made in 3+1 dimensions, where no alternative means of calculation exist.
Baryon number fluctuation and the quark-gluon plasma
Lin, ZW; Ko, Che Ming.
2001-01-01
We show that omega (B) or omega ((B) over bar), the squared baryon or antibaryon number fluctuation per baryon or antibaryon, is a possible signature for the quark-gluon plasma that is expected to be created in relativistic heavy ion collisions...
Bottom baryons from a dynamical lattice QCD simulation
Randy Lewis; R. M. Woloshyn
2009-01-12
Bottom baryon masses are calculated based on a 2+1 flavor dynamical lattice QCD simulation. The gauge field configurations were computed by the CP-PACS and JLQCD collaborations using an improved clover action. The bottom quark is described using lattice NRQCD. Results are presented for single and double-b baryons at one lattice spacing. Comparison with experimental values is discussed.
Delayed Afterglow Onset Interpreted as Baryon-Poor Viewing Angle
David Eichler
2005-03-24
We have suggested previously that baryons in GRB fireballs infiltrate from the surrounding walls that collimate the fireball. The efficiency $\\epsilon_b$ for generating blast energy can then be angle dependent. Delayed onset of afterglow can be interpreted as being due to a baryon-poor viewing angle.
Low-Energy Thermal Photons from Meson-Meson Bremsstrahlung
W. Liu; R. Rapp
2007-09-04
Within an effective hadronic model including electromagnetic interactions via a U$_{\\rm em}$(1) gauge, we reinvestigate photon Bremsstrahlung from a hot hadronic gas as expected to be formed in relativistic heavy-ion collisions at SPS energies. We calculate photon emission from the reactions $\\pi\\pi\\to\\pi\\pi\\gamma$ and $\\pi K \\to\\pi K\\gamma$ by an explicit (numerical) evaluation of the multi-dimensional phase space integral. This, in particular, allows to avoid the commonly employed soft photon approximation (SPA), as well as to incorporate final-state thermal enhancement factors. % during the hadronic stage of the fireball. Both improvements are shown to result in an appreciable increase of the photon production rate over previous hadronic calculations. Upon convolution over a thermal fireball we find an improvement in the description of recent low transverse-momentum WA98 data at SPS. The influence of both Landau-Pomeranchuk-Migdal and in-medium effects on "$\\sigma$" and $\\rho$-meson exchanges are briefly discussed.
The Baryon Catastrophe and the multiphase intracluster medium
K. F. Gunn; P. A. Thomas
1995-10-17
We review the theories and observations which together have led to the concept of the Baryon Catastrophe: observations of the baryon fraction on the scale of clusters of galaxies appear to be at least three times as high as the universal baryon fraction predicted by the theory of primordial nucleosynthesis in a flat, $\\Omega_0 = 1$, universe. We investigate whether this discrepancy could be eliminated by treating the intracluster gas as a multiphase medium, and find that this treatment both lowers the calculated mass of gas in a cluster and increases the inferred gravitational potential. These combined effects can reduce the calculated baryon fraction by between a quarter and a half: the precise amount depends upon the volume fraction distribution of density phases in the gas but is independent of the temperature profile across the cluster. Thus moving to a multiphase intracluster medium cannot resolve the Baryon Catastrophe by itself; other possible causes and explanations are discussed.
Investigation of semileptonic B meson decays to p-wave charm mesons
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1998-05-01
We have studied semileptonic B meson decays with a p-wave charm meson in the final state using 3.29 x 10(6) B (B) over bar events collected with the CLEO II detector at the Cornell Electron-Positron Storage Ring. We find ...
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.
Quantum Operator Design for Lattice Baryon Spectroscopy
Adam Lichtl
2007-09-06
A previously-proposed method of constructing spatially-extended gauge-invariant three-quark operators for use in Monte Carlo lattice QCD calculations is tested, and a methodology for using these operators to extract the energies of a large number of baryon states is developed. This work is part of a long-term project undertaken by the Lattice Hadron Physics Collaboration to carry out a first-principles calculation of the low-lying spectrum of QCD. The operators are assemblages of smeared and gauge-covariantly-displaced quark fields having a definite flavor structure. The importance of using smeared fields is dramatically demonstrated. It is found that quark field smearing greatly reduces the couplings to the unwanted high-lying short-wavelength modes, while gauge field smearing drastically reduces the statistical noise in the extended operators.
First observation of doubly charmed baryons
M. A. Moinester et al.
2003-09-25
The SELEX experiment (E781) at Fermilab has observed two statistically compelling high mass states near 3.6 GeV/c{sup 2}, decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +} and {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}. These final states are Cabibbo-allowed decay modes of doubly charmed baryons {Xi}{sub cc}{sup +} and {Xi}{sub cc}{sup ++}, respectively. The masses are in the range expected from theoretical considerations, but the spectroscopy is surprising. SELEX also has weaker preliminary evidence for a state near 3.8 GeV/c{sup 2}, a high mass state decaying to {Lambda}{sub c}{sup +} K{sup -} {pi}{sup +}{pi}{sup +}, possibly an excited {Xi}{sub cc}{sup ++} (ccu*). Data are presented and discussed.
Rare meson decays into very light neutralinos
Dreiner, H. K.; Grab, S.; Koschade, Daniel; Kraemer, M.; O'Leary, Ben; Langenfeld, Ulrich [Bethe Center for Theoretical Physics and Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen, Germany and Centre for Research in String Theory, Department of Physics, Queen Mary, University of London, E1 4NS London (United Kingdom); Institut fuer Theoretische Physik, RWTH Aachen University, 52056 Aachen (Germany); DESY, Platanenallee 6, D-15738 Zeuthen (Germany)
2009-08-01
We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the minimal supersymmetric standard model (MSSM) with and without minimal flavor violation. We present explicit formulas for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e., a massless neutralino is allowed. The branching ratios for kaon and B meson decays into light neutralinos may, however, be enhanced when one allows for nonminimal flavor violation. We find new constraints on the MSSM parameter space for such scenarios and discuss prospects for future kaon and B meson experiments. Finally, we comment on the search for light neutralinos in monojet signatures at the Tevatron and at the LHC.
A study of charm meson in heavy collisions
Di, Tiegang
2002-01-01
Using a local flavor SU(4) invariant Lagrangian, we study the interactions of charmed meson with pion, rho meson, and kaons. The coupling constants are determined either empirically or from relations based on the SU(4) symmetry. Form factors...
Dark Matter and the Baryon Asymmetry of the Universe
Glennys R. Farrar; Gabrijela Zaharijas
2004-07-06
We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\\sigma^{\\rm annih}_{\\bar{X}} < \\sigma^{\\rm annih}_{X} $, the $\\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If $m_X \\lsi 4.5 B_X $GeV and the annihilation cross sections differ by $\\gsi 10%$, this type of scenario naturally explains the observed $\\Omega_{DM} \\approx 5 \\Omega_b$.
Lepton Number Violation and the Baryon Asymmetry of the Universe
Harz, Julia; Päs, Heinrich
2015-01-01
Neutrinoless double beta decay, lepton number violating collider processes and the Baryon Asymmetry of the Universe (BAU) are intimately related. In particular lepton number violating processes at low energies in combination with sphaleron transitions will typically erase any pre-existing baryon asymmetry of the Universe. In this contribution we briefly review the tight connection between neutrinoless double beta decay, lepton number violating processes at the LHC and constraints from successful baryogenesis. We argue that far-reaching conclusions can be drawn unless the baryon asymmetry is stabilized via some newly introduced mechanism.
Static-light meson masses from twisted mass lattice QCD
Static-light meson masses from twisted mass lattice QCD Karl Jansen, Chris Michael, Andrea Shindler of Groningen. · Spain: University of Valencia. · Switzerland: University of Bern. Marc Wagner, "Static-light meson masses from twisted mass lattice QCD", July 16, 2008 #12;Introduction · Static-light meson
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.
New Paradigm for Baryon and Lepton Number Violation
Pavel Fileviez Perez
2015-08-17
The possible discovery of proton decay, neutron-antineutron oscillation, neutrinoless beta decay in low energy experiments, and exotic signals related to the violation of the baryon and lepton numbers at collider experiments will change our understanding of the conservation of fundamental symmetries in nature. In this review we discuss the rare processes due to the existence of baryon and lepton number violating interactions. The simplest grand unified theories and the neutrino mass generation mechanisms are discussed. The theories where the baryon and lepton numbers are defined as local gauge symmetries spontaneously broken at the low scale are discussed in detail. The simplest supersymmetric gauge theory which predicts the existence of lepton number violating processes at the low scale is investigated. The main goal of this review is to discuss the main implications of baryon and lepton number violation in physics beyond the Standard Model.
A-D-E Quivers and Baryonic Operators
Yuji Tachikawa; Futoshi Yagi
2007-10-25
We study baryonic operators of the gauge theory on multiple D3-branes at the tip of the conifold orbifolded by a discrete subgroup Gamma of SU(2). The string theory analysis predicts that the number and the order of the fixed points of Gamma acting on S^2 are directly reflected in the spectrum of baryonic operators on the corresponding quiver gauge theory constructed from two Dynkin diagrams of the corresponding type. We confirm the prediction by developing techniques to enumerate baryonic operators of the quiver gauge theory which includes the gauge groups with different ranks. We also find that the Seiberg dualities act on the baryonic operators in a non-Abelian fashion.
Observation of the ?[subscript b][superscript 0] Baryon
Bauer, Gerry P.
The observation of the bottom, strange baryon ?[subscript b][superscript 0] through the decay chain ?[subscript b][superscript 0]??[subscript c][superscript +]?[superscript -], where ?[subscript c][superscript +]??[superscript ...
Further evidence for narrow exotic low mass baryons
B. Tatischeff
2004-04-29
Although narrow low mass baryonic structures, observed mainly in SPES3 (Saturne) data, were not confirmed in recent experiments using lepton probes, their existence is confirmed in other data, where hadronic probes were used.
An AdS/QCD holographic wavefunction for the rho meson and diffractive rho meson electroproduction
J. R. Forshaw; R. Sandapen
2012-07-18
We show that AdS/QCD generates predictions for the rate of diffractive rho meson electroproduction that are in agreement with data collected at the HERA electron-proton collider.
K+ production in baryon-baryon and heavy-ion collisions
Li, GQ; Ko, Che Ming; Chung, WS.
1998-01-01
Kaon production cross sections in nucleon-nucleon, nucleon-Delta, and Delta-Delta interactions are studied in a boson exchange model. For the latter two interactions, the exchanged pion can be on-mass shell...only contributions due to a virtual pion an included via the Peierls method by taking into account the finite Delta width. With these cross sections and also those for pion-baryon interactions, subthreshold kaon production from heavy-ion collisions is studied in the relativistic transport model....
Versatile secondary beam for the meson area
Kirk, T.
1982-03-01
A new secondary beam design is outlined for the Meson M6 Beamline that combines versatility with economy. The beamline described will transport charged particles of either sign to 800 GeV/c and bring the beam to a focus in one of three potential experimental areas. The plan makes maximal use of existing civil construction.
Light Meson Dynamics Workshop. Mini proceedings
J. Bijnens; R. Escribano; S. Fang; S. Giovannella; W. Gradl; C. Hanhart; B. Kubis. S. Leupold; M. F. M. Lutz; P. Masjuan; B. Moussallam; A. Neiser; E. Oset; M. Ostrick; J. R. Pelaez; S. Scherer; A. Švarc; M. Unverzagt; R. Wanke; M. Wolke
2014-03-31
The mini-proceedings of the Light Meson Dynamics Workshop held in Mainz from February 10th to 12th, 2014, are presented. The web page of the conference, which contains all talks, can be found at https://indico.cern.ch/event/287442/overview .
Lattice investigation of heavy meson interactions
Björn Wagenbach; Pedro Bicudo; Marc Wagner
2014-11-10
We report on a lattice investigation of heavy meson interactions and of tetraquark candidates with two very heavy quarks. These two quarks are treated in the static limit, while the other two are up, down, strange or charm quarks of finite mass. Various isospin, spin and parity quantum numbers are considered.
Is the $\\eta$ Meson a Goldstone Boson?
Kirchbach, M
1996-01-01
The decoupling of the $\\eta$ meson from the nucleon, as recently deduced from analyzing $\\bar p p$ collisions and $\\eta$ photoproduction off the proton at threshold is shown to provide an argument against the Goldstone boson nature of the $\\eta $ meson. This argument depends neither on the mass of the $\\eta$ meson nor on its mixing to the $\\eta'$ meson but rather concerns the structure of the strong isoscalar axial vector current. In fact, a vanishing the hypercharge nucleon axial vector current. No partial conservation of the latter can be achieved therefore. This invalidates the Goldberger-Treiman type relation for the $\\eta N$ coupling constant within the context of the three-flavor quark model. We demonstrate that the suppressed $\\eta N$ coupling constant can be understood if the hypercharge and the singlet axial vector currents of the quark model are ideally mixed, as are those of the electroweak gauge theory. If so, the current algebra statement on the equal structure of the charged strong and weak curr...
Medium Effects on the Rho-Meson
Asakawa, M.; Ko, Che Ming.
1993-01-01
The property of a rho meson in dense nuclear matter is studied using the QCD sum rule. The spectral function appearing on the hadronic side of the sum rule is evaluated in the vector dominance model that takes into account the interaction between...
Meson wave function from holographic models
Alfredo Vega; Ivan Schmidt; Tanja Branz; Thomas Gutsche; Valery Lyubovitskij
2009-06-05
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.
Deeply Virtual Pseudoscalar Meson Production with CLAS
V. Kubarovsky; P. Stoler; I. Bedlinsky; for the CLAS Collaboration
2008-02-12
Deeply virtual meson scattering cross sections and asymmetries for the pi^0 and eta exclusive electroproduction in a very wide kinematic range of Q^2, t and x_B have been measured with CLAS (JLab). Initial analysis is already showing remarkable results. These data will help us to better understand the transition from soft to hard mechanisms.
Rare semi-leptonic B meson decays
Lyon, James David
2014-06-28
In this thesis, novel corrections to B ? X? and B ? Xl+l- decays, where X is a pseudoscalar or vector meson, are presented. These are the chromomagnetic matrix element, weak annihilation in a general four-quark operator basis and a long...
Masses of Flavor Singlet Hybrid Baryons
Olaf Kittel; Glennys R. Farrar
2000-10-17
We study the possibility that four iso-singlet baryons $\\Lambda_s(1405)$ $J^P=1/2^{-}$, $\\Lambda_s(1520)$ $J^P=3/2^{-}$, $\\Lambda_c(2593)$ $J^P=1/2^{-}$ and $\\Lambda_c(2625)$ $J^P=3/2^{-}$ are hybrids: three quark one gluon states (udsg). We calculate the mass separations of the candidates, using a degeneracy-lifting hyperfine interaction from an effective single colored gluon exchange between the constituents. The correct ordering of masses is obtained (contrary to the case for the conventional interpretation as 3 quarks with L=1) and the splittings are plausible. The parity of these states is not measured, only assumed to be negative. In the hybrid picture, the lightest states are parity even and the parity odd counterparts lie about 300 MeV higher. Thus the hybrid ansatz predicts that either the parity of the $\\Lambda(1405)$ etc is positive, or that there are undiscovered positive parity states about 300 MeV lower. We also remark that in this picture, the H-dibaryon mass may be around 1.5 GeV.
On the Parity Degeneracy of Baryons
Kirchbach, M
1997-01-01
The gross features of the observed baryon excitation spectrum below 2 GeV are well explained if the spectrum generating algebra of its intrinsic orbital angular momentum states is o(4)xsu(2)_I. The spins of the resonances are obtained through the coupling of a Lorentz bi-spinor {1/2,0}+{0,1/2} to a multiplet of the type {j,j} in its O(4)/O(3) reduction. The parities of the resonances follow from those of the O(3) members of the {j,j} multiplets. In this way relativistic SL(2,C) representations are constructed. For example, the first $S_{11}$, $P_{11}$, and D$_{13}$ states with masses around 1500 MeV fit into the {1/2,1/2}x[{1/2,0}+{0,1/2}] representation. The observed parities of the resonances correspond to natural parities of the {1/2,1/2} states. The second $P_{11}$, $S_{11}$, $D_{13}$ - together with the first $P_{13}$, $F_{15}$, $D_{15}$, and (a predicted) $F_{17}$-resonances, centered around 1700 MeV, are organized into the {3/2,3/2}x[{1/2,0}+{0,1/2}] representation. I argue that the members of the {3/2...
Hybrid meson decay from lattice QCD
Ziwen Fu
2012-09-10
Besides the conventional hadrons containing valence quarks and valence antiquarks, quantum chromodynamics (QCD) suggests the existence of the hybrid hadrons containing valence gluons in addition to the quarks and antiquarks, and some experiments may have found some. A decisive experimental confirmation of its existence, however, is still needed. At present, lattice simulations have offered the practicable ways of theoretically guiding us to search for the hybrid states. In this dissertation, we study the spectroscopy and the decay rate of the heavy hybrid mesons made of a heavy $b$ quark, a heavy $\\bar b$ antiquark, and a gluon ($b\\bar{b}g$) to selected channels, and use lattice methods to extract the transition matrix elements in full QCD. We are particular interested in the spin-exotic hybrid mesons. For sufficiently heavy quarks (e.g., $b$ quark), we use the leading Born-Oppenheimer (LBO) approximation to calculate the static potential energy at all $b\\bar{b}$ separations. Then, by solving the Schr\\"odinger equation with this potential, we reconstruct the motion of the heavy quarks. In a similar way we can determine decay rates. In this dissertation, we use the numerical lattice method to calculate the mass of the $f_0$ meson at a single lattice spacing and light quark mass, namely, $m_{f_0} = (768 \\pm 136)$ MeV. Most of all we consider the decay channels involving the production of a scalar meson. We obtain the partial decay rate ($\\Gamma$) for the channel $ H \\rightarrow \\chi_b + \\pi + \\pi $, namely, $ \\Gamma = 3.62(98)$ MeV. All of our results are consistent with those of other researchers. Knowledge of the masses and the decay rates should help us considerably in experimental searches for the hybrid mesons.
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Observation of the sigma_b baryons at CDF
Pursley, Jennifer M.; /Johns Hopkins U.
2007-03-01
We present a measurement of four new bottom baryons in proton-antiproton collisions with a center of mass energy of 1.96 TeV. Using 1.1 fb{sup -1} of data collected by the CDF II detector, we observe four {Lambda}{sup 0}{sub b}{pi}{+-} resonances in the fully reconstructed decay mode {Lambda}{sup 0}{sub b} {yields} {Lambda}{sup +}{sub c}{pi}{sup -}, where {Lambda}{sup +}{sub c} {yields} pK{sup -}{pi}{sup +}. The probability for the background to produce a similar or larger signal is less than 8.3 x 10{sup -8}, corresponding to a significance of greater than 5.2 {sigma}. We interpret these baryons as the {Sigma}{sub b}{sup (*){+-}} baryons.
Leptonic Decays of Charged Pseudoscalar Mesons - 2015
Rosner, Jonathan L; Van de Water, Ruth S
2015-01-01
We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be use...
Extracting the Flavour Structure of a Baryon-Number R-parity Violating Coupling at the LHC
B. C. Allanach; A. J. Barr; M. A. Parker; P. Richardson; B. R. Webber
2001-06-27
The detection of the flavour content of jets produced from R-parity violating neutralino decays is investigated in the case where one baryon-number violating coupling dominates. Simulations are performed of the ATLAS experiment at the LHC for all couplings, other than lambda"_tjk since neutralino decays through these couplings are very suppressed. Secondary vertex distributions and muons produced by heavy-quark (b- and c-) jets allow discrimination between LSP decay modes. The dominant coupling can be identified at better than 3.5 sigma in almost all cases, with the only remaining ambiguity caused by the inability to distinguish strange from down quarks.
Hybrid meson masses and the correlated Gaussian basis
Vincent Mathieu
2009-07-06
We revisited a model for charmonium hybrid meson with a magnetic gluon [Yu. S. Kalashnikova and A. V. Nefediev, Phys. Rev. D {\\bf 77}, 054025 (2008)] and improved the numerical calculations. These improvements support the hybrid meson interpretation of X(4260). Within the same model, we computed the hybrid meson mass with an electric gluon which is resolved to be lighter. Relativistic effects and coupling channels decreased also the mass.
Meson structure in light-front holographic QCD
Rohit Swarnkar; Dipankar Chakrabarti
2015-07-06
We consider the light-front holographic QCD with the light-front wave functions for mesons, modified for massive quarks. We evaluate the wave functions, distribution amplitudes, and form factors for $\\pi$, $\\rho$, $K$, and $J/\\psi$ mesons and photon-to-meson transition form factors for $\\pi$, $\\eta$, and $\\eta^\\prime$. The results are compared with the experimental data, wherever available.
Intrinsic frequencies of baryons in Skyrmion theory: origin of matter wave
Soon-Tae Hong
2015-05-23
Exploiting the Hamilton quantization in the Skyrmion thoery, we investigate intrinsic frequencies of baryons such as nucleon and delta particles. We find that matter wave property of the baryons originates from these intrinsic vibrational modes defined on internal hypersphere.
Baryon Asymmetry of the Universe in the Minimal Standard Model
Glennys R. Farrar; M. E. Shaposhnikov
1993-05-17
We calculate the baryon asymmetry of the Universe which would arise during a first order electroweak phase transition due to minimal standard model processes. It agrees in sign and magnitude with the observed baryonic excess, for resonable KM parameters and m$_t$ in the expected range, and plausible values of bubble velocity and other high temperature effects. A detailed version of this work (77pp) is being simultaneously submitted to the net. A shortened version of this recently appeared in Phys. Rev. Lett. {\\bf 70}, 2833, 1993.
Spectroscopy of triply charmed baryons from lattice QCD
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Padmanath, M.; Edwards, Robert G.; Mathur, Nilmani; Peardon, Michael
2014-10-14
The spectrum of excitations of triply-charmed baryons is computed using lattice QCD including dynamical light quark fields. The spectrum obtained has baryonic states with well-defined total spin up to 7/2 and the low-lying states closely resemble the expectation from models with an SU(6) x O(3) symmetry. As a result, energy splittings between extracted states, including those due to spin-orbit coupling in the heavy quark limit are computed and compared against data at other quark masses.
Spectroscopy of triply charmed baryons from lattice QCD
Padmanath, M.; Edwards, Robert G.; Mathur, Nilmani; Peardon, Michael
2014-10-01
The spectrum of excitations of triply-charmed baryons is computed using lattice QCD including dynamical light quark fields. The spectrum obtained has baryonic states with well-defined total spin up to 7/2 and the low-lying states closely resemble the expectation from models with an SU(6) x O(3) symmetry. Energy splittings between extracted states, including those due to spin-orbit coupling in the heavy quark limit are computed and compared against data at other quark masses.
Lorentz Covariant Spin-Grouping of Baryon Resonances
Kirchbach, M
1999-01-01
A well pronounced spin--grouping of baryon resonances to O(4) partial waves is found in baryon spectra and shown to be well interpreted in terms of Lorentz group representations of the type (1/2 +l', 1/2 +l')* [(1/2, 0)+(0,1/2)] with l' integer. In this way the relativistic description of finite dimensional resonance towers containing higher-spin states becomes possible. It is further argued that the nucleon excitations into the l'=1 and l'=2 multiplets are chiral phase transitions.
Spectroscopy of triply charmed baryons from lattice QCD
Padmanath, M; Edwards, Robert G; Mathur, Nilmani; Peardon, Michael
2014-10-01
The spectrum of excitations of triply-charmed baryons is computed using lattice QCD including dynamical light quark fields. The spectrum obtained has baryonic states with well-defined total spin up to 7/2 and the low-lying states closely resemble the expectation from models with an SU(6)x O(3) symmetry. Energy splittings between extracted states, including those due to spin-orbit coupling in the heavy quark limit are computed and compared against data at other quark masses.
The Meson Spectroscopy Program at the Jefferson Laboratory
Filippi, Alessandro; et. al.,
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.
CP violation for neutral charmed meson decays to CP eigenstates
Dongsheng Du
2006-11-06
CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.
Analyticity properties and unitarity constraints of heavy meson form factors
De Rafael, E; Eduardo de Rafael; Josep Taron; Rafael, Eduardo de; Taron, Josep
1994-01-01
We derive new bounds on the b-number form factor $F(q^2)$ of the B meson. (Revised version of hep-ph/9306214).
Search for Low Mass Exotic Baryons in One Pion Electroproduction Data Measured at JLAB
B. Tatischeff; E. Tomasi-Gustafsson
2007-02-05
This paper aims to give further evidence for the existence of low mass exotic baryons. Narrow structures in baryonic missing mass or baryonic invariant mass were previously observed during the last ten years. Since their existence is sometimes questionable, the structure functions of one pion electroproduction cross sections, measured at JLAB, are studied to add informations on the possible existence of these narrow exotic baryonic resonances.
Multiple scattering effects on heavy meson production in p+A...
Office of Scientific and Technical Information (OSTI)
Multiple scattering effects on heavy meson production in p+A collisions at backward rapidity Citation Details In-Document Search Title: Multiple scattering effects on heavy meson...
Baryon Asymmetry of the Universe (1/2)
None
2011-10-06
In two lectures, the following topics will be discussed: (1) Why baryon asymmetry is a problem at all (2) Review of the Sakharov's conditions (3) Why old models based on GUT did not work (4) Electroweak baryogenesis (5) Leptogenesis (6) Connections to the near-future experiments
Baryon Asymmetry of the Universe (2/2)
None
2011-10-06
In two lectures, the following topics will be discussed: (1) Why baryon asymmetry is a problem at all (2) Review of the Sakharov's conditions (3) Why old models based on GUT did not work (4) Electroweak baryogenesis (5) Leptogenesis (6) Connections to the near-future experiments
Why baryons matter: The kinematics of dwarf spheroidal satellites
Brooks, Alyson M. [Department of Astronomy, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706 (United States); Zolotov, Adi, E-mail: abrooks@physics.rutgers.edu, E-mail: zolotov@physics.huji.ac.il [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
2014-05-10
We use high-resolution cosmological simulations of Milky Way (MW) mass galaxies that include both baryons and dark matter (DM) to show that baryonic physics (energetic feedback from supernovae and subsequent tidal stripping) significantly reduces the DM mass in the central regions of luminous satellite galaxies. The reduced central masses of the simulated satellites reproduce the observed internal dynamics of MW and M31 satellites as a function of luminosity. We use these realistic satellites to update predictions for the observed velocity and luminosity functions of satellites around MW-mass galaxies when baryonic effects are accounted for. We also predict that field dwarf galaxies in the same luminosity range as the MW classical satellites should not exhibit velocities as low as the satellites because the field dwarfs do not experience tidal stripping. Additionally, the early formation times of the satellites compared to field galaxies at the same luminosity may be apparent in the star formation histories of the two populations. Including baryonic physics in cold dark matter (CDM) models naturally explains the observed low DM densities in the MWs dwarf spheroidal population. Our simulations therefore resolve the tension between kinematics predicted in CDM theory and observations of satellites, without invoking alternative forms of DM.
Pion photo- and electroproduction in relativistic baryon ChPT
Lothar Tiator; Stefan Scherer; Marius Hilt
2014-02-04
We present a calculation of pion photo- and electroproduction in manifestly Lorentz-invariant baryon chiral perturbation theory up to and including order q^4. We fix the low-energy constants by fitting experimental data in all available reaction channels. Our results can be accessed via a web interface, the so-called chiral MAID.
Leptonic Decays of Charged Pseudoscalar Mesons - 2015
Jonathan L. Rosner; Sheldon Stone; Ruth S. Van de Water
2015-09-07
We review the physics of purely leptonic decays of $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ pseudoscalar mesons. The measured decay rates are related to the product of the relevant weak-interaction-based CKM matrix element of the constituent quarks and a strong interaction parameter related to the overlap of the quark and antiquark wave-functions in the meson, called the decay constant $f_P$. The leptonic decay constants for $\\pi^\\pm$, $K^\\pm$, $D^{\\pm}$, $D_s^\\pm$, and $B^\\pm$ mesons can be obtained with controlled theoretical uncertainties and high precision from {\\it ab initio} lattice-QCD simulations. The combination of experimental leptonic decay-rate measurements and theoretical decay-constant calculations enables the determination of several elements of the CKM matrix within the standard model. These determinations are competitive with those obtained from semileptonic decays, and also complementary because they are sensitive to different quark flavor-changing currents. They can also be used to test the unitarity of the first and second rows of the CKM matrix. Conversely, taking the CKM elements predicted by unitarity, one can infer "experimental" values for $f_P$ that can be compared with theory. These provide tests of lattice-QCD methods, provided new-physics contributions to leptonic decays are negligible at the current level of precision. This review is the basis of the article in the Particle Data Group's 2016 edition, updating the versions in Refs. [1-3].
Photoproduction of mesons off nuclei B. Krusche,1
Krusche, Bernd
Abstract Photoproduction of mesons off nuclei, in particular the deuteron, helium-, and lithium. The aim of these measurements was twofold: the study of meson production reactions off quasi-free neutrons the observation of a narrow structure, of as yet unknown nature, in the excitation function of production off
Static-light meson masses from twisted mass lattice QCD
ETM Collaboration; Karl Jansen; Chris Michael; Andrea Shindler; Marc Wagner
2008-08-15
We compute the static-light meson spectrum using two-flavor Wilson twisted mass lattice QCD. We have considered five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV. We have extrapolated our results, to make predictions regarding the spectrum of B and B_s mesons.
Meson Production at Low Proton Beam Energy X. Ding, UCLA
McDonald, Kirk
Meson Production at Low Proton Beam Energy (Update) X. Ding, UCLA Target Studies May 9, 2013 15; Â· Meson Production at low proton beam energy (below 4 GeV) seems higher for Ga than Hg from our kinetic energy Â· EM: The hadron threshold energy (Default: 0.0145 GeV) Â· EPSTAM: The star production
The charmed and bottom meson spectrum from lattice NRQCD
Randy Lewis; R. M. Woloshyn
2000-10-02
The mass spectrum of S and P-wave mesons containing a single heavy quark has been computed using quenched lattice nonrelativistic QCD. Numerical results have been obtained at first, second and third order in the heavy quark expansion, so convergence can be discussed. The computed spectrum of charmed and bottom mesons is compared to existing model calculations and experimental data.
Heavy-light meson spectrum with and without NRQCD
Randy Lewis; R. M. Woloshyn
2000-10-02
Results for the spectrum of S and P-wave charmed mesons are obtained in the quenched approximation from a tadpole-improved anisotropic gauge field action and a D234 quark action. This is compared to the spectrum obtained from an NRQCD charm quark and a D234 light antiquark. NRQCD results for bottom mesons are also discussed.
Production of and Mesons on Nucleons and Nuclei
Krusche, Bernd
Production of and Mesons on Nucleons and Nuclei B. Krusche1 and C. Wilkin2 1 Department Street, London WC1E 6BT, UK October 23, 2014 Abstract The production of and mesons in photon known about the production of the or of pairs, these also offer tantalizing prospects in the search
Mesons: Relativistic Bound States with String Tension
Anishetty, R; Anishetty, Ramesh; Kudtarkar, Santosh Kumar
2003-01-01
A systematic method of analysing Bethe-Salpeter equation using spectral representation for the relativistic bound state wave function is given. This has been explicitly applied in the context of perturbative QCD with string tension in the $1 \\over N$ expansion. We show that there are only a few stable bound state mesons due to the small "threshold mass"(constituent mass) of quarks. The asymptotic properties of the bound states are analytically analysed. The spectrum is derived analytically and compared phenomenologically. Chiral symmetry breaking and PCAC results are demonstrated. We make a simple minded observation to determine the size of the bound states as a function of the energy of the boundstate.
QCD description of backward vector meson hard electroproduction
B. Pire; K. Semenov-Tian-Shansky; L. Szymanowski
2015-03-10
We consider backward vector meson exclusive electroproduction off nucleons in the framework of collinear QCD factorization. Nucleon to vector meson transition distribution amplitudes 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 ($\\sigma_T \\gg \\sigma_L$) and in the characteristic $1/Q^8$-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 $\\rho^0$, $\\omega$ and $\\phi$ meson production off protons. The resulting cross sections are shown to be measurable in the forthcoming JLab@12 GeV experiments.
Interference in Exclusive Vector Meson Production in Heavy Ion Collisions
Spencer R. Klein; Joakim Nystrand
1999-09-03
Photons emitted from the electromagnetic fields of relativistic heavy ions can fluctuate into quark anti-quark pairs and scatter from a target nucleus, emerging as vector mesons. These coherent interactions are identifiable by final states consisting of the two nuclei and a vector meson with a small transverse momentum. The emitters and targets can switch roles, and the two possibilities are indistinguishable, so interference may occur. Vector mesons are negative parity so the amplitudes have opposite signs. When the meson transverse wavelength is larger than the impact parameter, the interference is large and destructive. The short-lived vector mesons decay before amplitudes from the two sources can overlap, and so cannot interfere directly. However, the decay products are emitted in an entangled state, and the interference depends on observing the complete final state. The non-local wave function is an example of the Einstein-Podolsky-Rosen paradox.
Hyperfine meson splittings: chiral symmetry versus transverse gluon exchange
Llanes-Estrada, Felipe J; Swanson, Eric S; Szczepaniak, Adam P; Llanes-Estrada, Felipe J.; Cotanch, Stephen R.; Szczepaniak, Adam P.; Swanson, Eric S.
2004-01-01
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 $\\eta_b$ mass is predicted to be around 9400 MeV consistent w...
Light meson emission in (anti)proton induced reactions
E. A. Kuraev; E. S. Kokoulina; E. Tomasi-Gustafsson
2015-03-07
Reactions induced by high energy antiprotons on proton on nuclei are accompanied with large probability by the emission of a few mesons. Interesting phenomena can be observed and QCD tests can be performed, through the detection of one or more mesons. The collinear emission from high energy (anti)proton beams of a hard pion or vector meson, can be calculated similarly to the emission of a hard photon from an electron \\cite{Kuraev:2013izz}. This is a well known process in QED, and it is called the "Quasi-Real Electron method", where the incident particle is an electron and a hard photon is emitted leaving an 'almost on shell' electron impinging on the target \\cite{Baier:1973ms}. Such process is well known as Initial State Emission (ISR) method of scanning over incident energy, and can be used, in the hadron case, to produce different kind of particles in similar kinematical conditions. In case of emission of a charged light meson, $\\pi$ or $\\rho$-meson, in proton-proton(anti-proton) collisions, the meson can be deviated in a magnetic field and detected. The collinear emission (along the beam direction) of a charged meson may be used to produce high energy (anti)neutron beams. This can be very useful to measure the difference of the cross sections of (anti)proton and (anti)neutron scattering from the target and may open the way for checking sum rules with antiparticles. Hard meson emission allows also to enhance the cross section when the energy loss from one of the incident particles lowers the total energy up to the mass of a resonance. The cross section can be calculated, on the basis of factorized formulas, where the probability of emission of the light mesons multiplies the cross section of the sub-process. Multiplicity distributions for neutral and charged meson production are also given.
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.
Nuclear and nucleon transitions of the H di-baryon
Glennys R. Farrar; Gabrijela Zaharijas
2003-08-12
We consider 3 types of processes pertinent to the phenomenology of an H di-baryon: conversion of two $\\Lambda$'s in a doubly-strange hypernucleus to an H, decay of the H to two baryons, and -- if the H is light enough -- conversion of two nucleons in a nucleus to an H. We compute the spatial wavefunction overlap using the Isgur-Karl and Bethe-Goldstone wavefunctions, and treat the weak interactions phenomenologically. The observation of $\\Lambda$ decays from doubly-strange hypernuclei puts a constraint on the H wavefunction which is plausibly satisfied. In this case the H is very long-lived as we calculate. An absolutely stable H is not excluded at present. SuperK can provide valuable limits.
Large Nc QCD and Models of Exotic Baryons
Thomas D. Cohen
2004-07-15
Exotic baryons have been predicted in the context of the chiral soliton model. These states have been identified with strangeness +1 resonances reported in a number of experiments. In this talk it is pointed out that the technique used to quantize these solitons in most conventional treatments depends on dynamical assumptions beyond those in standard large Nc physics. These additional assumptions have never been justified.
Baryon photo-decay amplitudes at the pole
R. L. Workman; L. Tiator; A. Sarantsev
2013-04-15
We derive relations for baryon photo-decay amplitudes both for the Breit-Wigner and the pole positions. With an updated SAID partial wave analysis, technically similar to the earliest Virginia Tech analysis of photoproduction data, we compare photo-decay amplitudes at both resonance positions for a few selected nucleon resonances. Comparisons are made and a qualitative similarity, seen between the pole and Breit-Wigner values extracted by the Bonn-Gatchina group, is confirmed in the present study.
Study of Chemical Equilibration of a Baryon Rich QGP
Abhijit Sen
2008-12-14
Parton equilibration studies for thermally equilibrated but chemically non-equilibrated quark-gluon-plasma (QGP), likely to be formed at the relativistic colliders at BNL and CERN is presented.Parton equilibration is studied enforcing baryon number conservation. Process like quark-flavor interchanging is also taken into consideration.The degree of equilibration is studied comparatively for the various reactions/ constraints that are being considered.
Transitions of two baryons to the H dibaryon in nuclei
Glennys R. Farrar; Gabrijela Zaharijas
2003-03-05
We calculate the suppression in the rate at which two baryons in a nucleus (viz., nucleons or $\\Lambda$'s) convert to an H dibaryon, using an Isgur-Karl wavefunction for quarks in the baryons and H, and a Bethe-Goldstone wavefunction for the baryons in the nucleus. If $r_H \\lsi 1/3~ r_N$, we find $\\tau_{A_{\\Lambda\\Lambda}\\to A'_H}\\gsi \\tau_\\Lambda$ and the observation of $\\Lambda$ decays from double-$\\Lambda$ hypernuclei does not exclude the existence of the H. If $m_H < 2 m_p$, nuclei are unstable but have very long lifetimes. For reasonable values of $r_H$ and the nuclear wavefunction, the lifetime can be long enough to evade anticipated SuperK limits $\\tau_{A_{NN}\\to A'_H}\\gsi {\\rm few} 10^{29}$ yr, or short enough to be observed. An analysis of SuperK data to look for this possibility should be undertaken.
A Baryonic Solution to the Missing Satellites Problem
Brooks, Alyson M.; Kuhlen, Michael; Zolotov, Adi; Hooper, Dan
2013-03-01
It has been demonstrated that the inclusion of baryonic physics can alter the dark matter densities in the centers of low-mass galaxies, making the central dark matter slope more shallow than predicted in pure cold dark matter simulations. This flattening of the dark matter profile can occur in the most luminous subhalos around Milky Way mass galaxies. Zolotov et al. have suggested a correction to be applied to the central masses of dark matter-only satellites in order to mimic the affect of (1) the flattening of the dark matter cusp due to supernova feedback in luminous satellites and (2) enhanced tidal stripping due to the presence of a baryonic disk. In this paper, we apply this correction to the z = 0 subhalo masses from the high resolution, dark matter-only Via Lactea II (VL2) simulation, and find that the number of massive subhalos is dramatically reduced. After adopting a stellar mass to halo mass relationship for the VL2 halos, and identifying subhalos that are (1) likely to be destroyed by stripping and (2) likely to have star formation suppressed by photo-heating, we find that the number of massive, luminous satellites around a Milky Way mass galaxy is in agreement with the number of observed satellites around the Milky Way or M31. We conclude that baryonic processes have the potential to solve the missing satellites problem
Higher radial and orbital excitations in the charmed meson family
Qin-Tao Song; Dian-Yong Chen; Xiang Liu; Takayuki Matsuki
2015-09-16
Considering abundant experimental information of charmed mesons and the present research status, in this work we systematically study higher radial and orbital excitations in the charmed meson family by analyzing the mass spectrum and calculating their two-body OZI-allowed decay behaviors. This phenomenological analysis not only reveals underlying propertes of the newly observed charmed states $D(2550)$, $D^*(2600)$, $D^*(2760)$, $D(2750)$, $D_J(2580)$, $D^*_J(2650)$, $D^*_J(2760)$, $D_J(2740)$, $D_J(3000)$ and $D^*_J(3000)$, but also provides valuable information of the charmed mesons still missing in experiments.
Transport properties of a meson gas
D. Fernandez-Fraile; A. Gomez Nicola
2007-07-09
We present recent results on a systematic method to calculate transport coefficients for a meson gas (in particular, we analyze a pion gas) at low temperatures in the context of Chiral Perturbation Theory. Our method is based on the study of Feynman diagrams with a power counting which takes into account collisions in the plasma by means of a non-zero particle width. In this way, we obtain results compatible with analysis of Kinetic Theory with just the leading order diagram. We show the behavior with temperature of electrical and thermal conductivities and shear and bulk viscosities, and we discuss the fundamental role played by unitarity. We obtain that bulk viscosity is negligible against shear viscosity near the chiral phase transition. Relations between the different transport coefficients and bounds on them based on different theoretical approximations are also discussed. We also comment on some applications to heavy-ion collisions.
Hydrogen like classification for light nonstrange mesons
S. S. Afonin
2008-09-09
The recent experimental results on the spectrum of highly excited light nonstrange mesons are known to reveal a high degree of degeneracy among different groups of states. We revise some suggestions about the nature of the phenomenon and put the relevant ideas into the final shape. The full group of approximate mass degeneracies is argued to be $SU(2)_f\\times I\\times O(4)$, where $I$ is the degeneracy of isosinglets and isotriplets and O(4) is the degeneracy group of the relativistic hydrogen atom. We discuss the dynamical origin and consequences of considered symmetry with a special emphasis on distinctions of this symmetry from the so-called chiral symmetry restoration scenario.
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.
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Meson-meson bound state in a 2+1 lattice QCD model with two flavors and strong coupling
Faria da Veiga, Paulo A.; O'Carroll, Michael; Neto, Antonio Francisco
2005-08-01
We consider the existence of bound states of two mesons in an imaginary-time formulation of lattice QCD. We analyze an SU(3) theory with two flavors in 2+1 dimensions and two-dimensional spin matrices. For a small hopping parameter and a sufficiently large glueball mass, as a preliminary, we show the existence of isoscalar and isovector mesonlike particles that have isolated dispersion curves (upper gap up to near the two-particle threshold {approx}-4ln{kappa}). The corresponding meson masses are equal up to and including O({kappa}{sup 3}) and are asymptotically of order -2ln{kappa}-{kappa}{sup 2}. Considering the zero total isospin sector, we show that there is a meson-meson bound state solution to the Bethe-Salpeter equation in a ladder approximation, below the two-meson threshold, and with binding energy of order b{kappa}{sup 2}{approx_equal}0.02359{kappa}{sup 2}. In the context of the strong coupling expansion in {kappa}, we show that there are two sources of meson-meson attraction. One comes from a quark-antiquark exchange. This is not a meson exchange, as the spin indices are not those of the meson particle, and we refer to this as a quasimeson exchange. The other arises from gauge field correlations of four overlapping bonds, two positively oriented and two of opposite orientation. Although the exchange part gives rise to a space range-one attractive potential, the main mechanism for the formation of the bound state comes from the gauge contribution. In our lattice Bethe-Salpeter equation approach, this mechanism is manifested by an attractive distance-zero energy-dependent potential. We recall that no bound state appeared in the one-flavor case, where the repulsive effect of Pauli exclusion is stronger.
Toward the excited isoscalar meson spectrum from lattice QCD
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
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 ?, ?' 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
Incoherent photoproduction of $?$-meson from deuteron at low energies
Alvin Kiswandhi; YuBing Dong; Shin Nan Yang
2014-02-14
The LEPS and CLAS data of the incoherent photoproduction of $\\phi$ meson from deuteron at low energies are studied with a model for $\\phi$ meson photoproduction from nucleon consisting of Pomeron, $\\pi$, and $\\eta$ meson exchanges in the t-channel, and a postulated resonance, with parameters fitted to recent LEPS data on $\\phi$ production from proton near threshold. The resonance was introduced to explain an observed bump in the forward differential cross section. Within impulse approximation, we find that the Fermi motion, final state interaction, and the resonance excitation all give important contributions to improve the agreement with data. However, discrepancies remain. Contributions from $\\phi$ production via spectator nucleon by other mesons like $\\pi, \\rho,$ and $\\phi$ produced from the first nucleon need to be calculated in order to gain insight on the medium effects as well as the existence of the postulated nucleon resonance.
Medium modifications of the rho meson in nuclear photoproduction
Riek, F.; Rapp, Ralf; Oh, Yongseok; Lee, T. -S H.
2010-01-01
We extend our recent study of dilepton invariant-mass spectra from the decays of rho mesons produced by photon reactions off nuclei. We specifically focus on experimental spectra as recently measured by the CLAS Collaboration ...
S-wave charmed mesons in lattice NRQCD
Randy Lewis; R. M. Woloshyn
1998-09-04
Heavy-light mesons can be studied using the 1/M expansion of NRQCD, provided the heavy quark mass is sufficiently large. Calculations of the S-wave charmed meson masses from a classically and tadpole-improved action are presented. A comparison of O(1/M), O(1/M^2) and O(1/M^3) results allows convergence of the expansion to be discussed. It is shown that the form of discretized heavy quark propagation must be chosen carefully.
Lao, Hai-Ling; Liu, Fu-Hu; Lacey, Roy A
2016-01-01
Transverse momentum distributions of positively charged mesons (positive pions $\\pi^+$ and positive kaons $K^+$), baryons (protons $p$), and light fragments (deuterons $d$ and one of helium isotopes $^3$He) produced in mid-rapidity interval ($|y|energy per nucleon pair $\\sqrt{s_{NN}}=2.76$ TeV, are uniformly and approximately described by the Tsallis statistics. The dependences of parameteres (effective temperature, entropy index, and normalization constant) on centrality and rest mass are obtained. The source temperature and particle transverse (or radial) flow velocity at the kinetic freeze-out of the interacting system are obtained from the relations between effective temperature and rest mass as well as mean transverse momentum and rest mass, respectively.
CP Violation and the Baryonic Asymmetry of the Universe
Glennys Farrar
1995-02-16
The physics of electroweak baryogenesis is described with the aim of making the essentials clear to non-experts. Several models for the source of the necessary CP violation are discussed: CKM phases as in the minimal standard model, general two higgs doublet models, the supersymmetric standard model, $Z$ condensates, and the singlet majoron model. In a more technical section, a strategy is introduced for consistently treating quark dynamics in the neighborhood of the bubble wall, where both local and non-local interactions are important. This provides a method for deciding whether gluonic corrections wash out the elecroweak contribution to the baryonic asymmetry in the minimal standard model.
Saving fourth generation and baryon number by living long
Hitoshi Murayama; Vikram Rentala; Jing Shu; Tsutomu T. Yanagida
2010-12-01
Recent studies of precision electroweak observables have led to the conclusion that a fourth generation is highly constrained. However, we point out that a long-lived fourth generation can reopen a large portion of the parameter space. In addition, it preserves baryon and lepton asymmetries against sphaleron erasure even if $B-L=0$. It opens up the possibility of exact $B-L$ symmetry and hence Dirac neutrinos. The fourth generation can be observed at the LHC with unique signatures of long-lived particles in the near future.
Correlating the skewness and kurtosis of baryon number distributions
Wei-jie Fu; Jan M. Pawlowski
2015-12-28
The skewness and the kurtosis of the baryon number distributions are computed within QCD-improved low energy effective models including quantum thermal and density fluctuations. The results are compared with the Beam Energy Scan experiment at RHIC. The theoretical results agree with the experimental measurements up to errors, for the colliding energy $\\sqrt{s}\\ge 19.6\\,\\mathrm{GeV}$. For smaller colliding energies a discrepancy between theoretical and experimental results develops. This is explained with the lack of precision of the current set-up for small colliding energies. It is outlined how this deficiency can be overcome.
Heavy-baryon quark model picture from lattice QCD
J. Vijande; A. Valcarce; H. Garcilazo
2015-07-14
The ground state and excited spectra of baryons containing three identical heavy quarks, $b$ or $c$, have been recently calculated in nonperturbative lattice QCD. The energy of positive and negative parity excitations has been determined with high precision. Lattice results constitute a unique opportunity to learn about the quark-confinement mechanism as well as elucidating our knowledge about the nature of the strong force. We analyze the nonperturbative lattice QCD results by means of heavy-quark static potentials derived using SU(3) lattice QCD. We make use of different numerical techniques for the three-body problem.
Baryon resonances without quarks: A chiral soliton perspective
Karliner, M.
1987-03-01
In many processes involving low momentum transfer it is fruitful to regard the nucleon as a soliton or ''monopole-like'' configuration of the pion field. In particular, within this framework it is possible to obtain detailed predictions for pion-nucleon scattering amplitudes and for properties of baryon resonances. One can also derive model-independent linear relations between scattering amplitudes, such as ..pi..N and anti KN. A short survey of some recent results is given, including comparison with experimental data.
Fermionic Quasiparticles in QCD at High Baryon Density
Thomas Schaefer
2005-10-24
We study fermionic quasi-particles in QCD at very high baryon density. In the normal quark matter phase unscreened magnetic gluon exchanges lead to non-Fermi liquid behavior. Non-Fermi liquid effects manifest themselves in low energy Green functions that depend on logarithms and fractional powers of energy. In the superfluid phase there is an energy gap for fermionic excitations. Quark mass effects can cause the energy gap to vanish. Gapless fermions in the color flavor locked phase cause an instability towards a state with a non-zero supercurrent.
Measurement of D* Mesons in Jets from p + p Collisions at sqrt s = 200 GeV
Coffin, J.P.; STAR Collaboration
2009-01-01
Measurement of D* Mesons in Jets from p + p Collisions at ?sMeasurement of D ? Mesons in Jets from p + p Collisions at sD ? mesons in inclusive jets produced in proton-proton
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.
RELATIVISTIC QUARK MODELS FOR BARYONS: THE EXTRAORDINARY WORLD OF ORDINARY MATTER.
Gent, Universiteit
properties of strange baryons. 1. The trouble with medium-energy The words "fundamental theory of matter quarks, starting from the fundamental equations of quantum chromody- namics (QCD), the field theory Lorentz covariant. We have used this model to calculate baryon mass spectra, as well as electromagnetic
Decays of Z boson into pseudoscalar meson pair of different flavours
Chia, Swee-Ping [High Impact Research, University of Malaya, 50603 Kuala Lumpur (Malaysia)
2014-03-05
We analyse the process Z°?M{sub 1}M{sub 2}, where M{sub 1} and M{sub 2} are pseudoscalar mesons with quark contents of q{sub 1}q{sup ¯} and qq{sup ¯}{sub 2} respectively. At the quark level, the process Z°?q{sub 1}q{sup ¯}{sub 2}, where q{sub 1} and q{sub 2} are quarks of different flavours, receives contribution only from the Z-penguin. In order to fold the quark-level process to the hadronic process, we make the fundamental assumption that the vertex of type Mqq{sup ¯} can be approximated by an effective constant ?5 coupling. With this assumption, estimates are obtained for the cross-sections for the following processes: Z°?K{sup ?}?{sup +}, Z°?B{sup ?}K{sup +}.
Probing the spin-parity of the pentaquark $\\Theta^+$ baryon
Barmin, V V; Curceanu, C; Davidenko, G V; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tarasov, V V
2015-01-01
Using the DIANA data on the charge-exchange reaction K^+n --> pK^0 on a bound neutron, in which the s-channel formation of the pentaquark baryon \\Theta^+(1538) has been observed,we analyze the dependence of the background-subtracted \\Theta^+ --> pK^0 signal on the K^0 emission angle in the pK^0 rest frame. The data are consistent with the angular dependence of a form dW/d\\cos\\Theta_cms ~ (\\cos\\Theta_cms + A)^2 with a positive offset A. This form of the \\cos\\Theta_cms distribution suggests an interference between the \\Theta-mediated p-wave contribution and the nonresonant s-wave contribution to the total amplitude of the charge-exchange reaction. The p-wave nature of the \\Theta-mediated amplitude is consistent with the spin-parity assignment of 1/2^+ for the \\Theta^+ baryon. The selection in \\cos\\Theta_cms based on the observed angular dependence of the \\Theta^+ --> pK^0 signal allows to boost the statistical significance of the signal up to 6.8 standard deviations. \\e
Probing the spin-parity of the pentaquark $?^+$ baryon
DIANA Collaboration; V. V. Barmin; A. E. Asratyan; C. Curceanu; G. V. Davidenko; C. Guaraldo; M. A. Kubantsev; I. F. Larin; V. A. Matveev; V. A. Shebanov; N. N. Shishov; L. I. Sokolov; V. V. Tarasov
2015-08-02
Using the DIANA data on the charge-exchange reaction K^+n --> pK^0 on a bound neutron, in which the s-channel formation of the pentaquark baryon \\Theta^+(1538) has been observed,we analyze the dependence of the background-subtracted \\Theta^+ --> pK^0 signal on the K^0 emission angle in the pK^0 rest frame. The data are consistent with the angular dependence of a form dW/d\\cos\\Theta_cms ~ (\\cos\\Theta_cms + A)^2 with a positive offset A. This form of the \\cos\\Theta_cms distribution suggests an interference between the \\Theta-mediated p-wave contribution and the nonresonant s-wave contribution to the total amplitude of the charge-exchange reaction. The p-wave nature of the \\Theta-mediated amplitude is consistent with the spin-parity assignment of 1/2^+ for the \\Theta^+ baryon. The selection in \\cos\\Theta_cms based on the observed angular dependence of the \\Theta^+ --> pK^0 signal allows to boost the statistical significance of the signal up to 7.1 standard deviations.
Flavor-singlet hybrid baryons may already have been discovered
Olaf Kittel; Glennys R. Farrar
2005-08-12
The splittings between the spin 1/2 and spin 3/2 iso-singlet baryons Lambda_s(1405) and Lambda_s(1520), and their charmed counterparts Lambda_c(2593) and Lambda_c(2625), have been a theoretical conundrum. Here we investigate the possibility that the QCD binding of color octets comprised of three quarks in a flavor singlet configuration is stronger than previously envisaged, allowing these states to be interpreted as hybrids consisting of three quarks plus a valence gluon (udsg) and (udcg). A fit of their mass separation allows the mass prediction of the strange and charmed flavor octet and decuplet hybrid baryons and the prediction of the mass separation of the beauty hybrids. Such hybrid states come in parity-doubled pairs with the even parity state lighter by about 300 MeV. Existing data accommodates either parity assignment for the observed states and the existence of the required unobserved partners at either higher or lower mass. We discuss difficulties with and strategies for observing the other states under the two cases. A corollary of the strong-binding-in-flavor-singlet-channel hypothesis is that the H-dibaryon may be very long lived or stable with m_H ~< 2 GeV.
Baryon Oscillations and Dark-Energy Constraints from Imaging Surveys
Derek Dolney; Bhuvnesh Jain; Masahiro Takada
2004-09-20
Baryonic oscillations in the galaxy power spectrum have been studied as a way of probing dark-energy models. While most studies have focused on spectroscopic surveys at high redshift, large multi-color imaging surveys have already been planned for the near future. In view of this, we study the prospects for measuring baryonic oscillations from angular statistics of galaxies binned using photometric redshifts. We use the galaxy bispectrum in addition to the power spectrum; this allows us to measure and marginalize over possibly complex galaxy bias mechanisms to get robust cosmological constraints. In our parameter estimation we allow for a weakly nonlinear biasing scheme that may evolve with redshift by two bias parameters in each of ten redshift bins. We find that a multi-color imaging survey that probes redshifts beyond one can give interesting constraints on dark-energy parameters. In addition, the shape of the primordial power spectrum can be measured to better accuracy than with the CMB alone. We explore the impact of survey depth, area, and calibration errors in the photometric redshifts on dark-energy constraints.
Lorentz Multiplet Structure of Baryon Spectra and Relativistic Description
Kirchbach, M
1997-01-01
The pole positions of the various baryon resonances are known to reveal well-pronounced clustering, so-called Hoehler clusters. For nonstrange baryons the Hoehler clusters are shown to be identical to Lorentz multiplets of the type (j,j)*[(1/2,0)+(0,1/2)] with j being a half-integer. For the Lambda hyperons below 1800 MeV these clusters are shown to be of the type [(1,0)+ (0,1)]*[(1/2,0)+(0,1/2)] while above 1800 MeV they are parity duplicated (J,0)+(0,J) (Weinberg-Ahluwalia) states. Therefore, for Lambda hyperons the restoration of chiral symmetry takes place above 1800 MeV. Finally, it is demonstrated that the description of spin-3/2 particles in terms of a 2nd rank antisymmetric Lorentz tensor with Dirac spinor components does not contain any off-shell parameters and avoids the main difficulties of the Rarita-Schwinger description based upon a 4-vector with Dirac spinor components.
Dense baryonic matter: constraints from recent neutron star observations
Thomas Hell; Wolfram Weise
2014-09-24
Updated constraints from neutron star masses and radii impose stronger restrictions on the equation of state for baryonic matter at high densities and low temperatures. The existence of two-solar-mass neutron stars rules out many soft equations of state with prominent "exotic" compositions. The present work reviews the conditions required for the pressure as a function of baryon density in order to satisfy these new constraints. Several scenarios for sufficiently stiff equations of state are evaluated. The common starting point is a realistic description of both nuclear and neutron matter based on a chiral effective field theory approach to the nuclear many-body problem. Possible forms of hybrid matter featuring a quark core in the center of the star are discussed using a three-flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model. It is found that a conventional equation of state based on nuclear chiral dynamics meets the astrophysical constraints. Hybrid matter generally turns out to be too soft unless additional strongly repulsive correlations, e.g. through vector current interactions between quarks, are introduced. The extent to which strangeness can accumulate in the equation of state is also discussed.
Accuracy of cosmological parameters using the baryon acoustic scale
Thepsuriya, Kiattisak; Lewis, Antony E-mail: antony@cosmologist.info
2015-01-01
Percent-level measurements of the comoving baryon acoustic scale standard ruler can be used to break degeneracies in parameter constraints from the CMB alone. The sound horizon at the epoch of baryon drag is often used as a proxy for the scale of the peak in the matter density correlation function, and can conveniently be calculated quickly for different cosmological models. However, the measurements are not directly constraining this scale, but rather a measurement of the full correlation function, which depends on the detailed evolution through decoupling. We assess the level of reliability of parameter constraints based on a simple approximation of the acoustic scale compared to a more direct determination from the full numerical two-point correlation function. Using a five-parameter fitting technique similar to recent BAO data analyses, we find that for standard ?CDM models and extensions with massive neutrinos and additional relativistic degrees of freedom, the approximation is at better than 0.15% for most parameter combinations varying over reasonable ranges.
A study of B Meson lifetime at the KEK B Nakadaira Takeshi1
Aihara, Hiroaki
) . . . . . . . . . . . . . 8 2.3.6 Electromagnetic Calorimeter (ECL) . . . . . . . . . . . 9 2.3.7 Super-conducting Solenoid amount of B mesons is provided by accelerator. And B mesons produced by asymmetric e+ e- collider
J/psi absorption by nucleons in the meson-exchange model
Oh, Yongseok; Liu, Wei; Ko, Che Ming.
2007-01-01
We reinvestigate the J/Psi dissociation processes induced by the reactions with nucleons, J/Psi + N -> D-(*) + Lambda(c), in the meson- exchange model. Main constraints used in this work are vector- meson dominance and charm vector...
Hadronic production of eta--mesons: recent results and open questions
C. Hanhart
2005-11-17
I review recent insights and open questions connected with the production of eta--mesons from hadrons.
Introducing light vector and axial vector mesons in the union of chiral and heavy quark symmetries
Kamal, A.N.; Xu, Q.P. (Theoretical Physics Institute and Department of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1 (Canada))
1994-02-01
We introduce light vector and axial vector mesons as gauge particles in a (broken) local SU[sub [ital L
Bc Meson Formfactors and Bc-->PV Decays Involving Flavor Dependence of Transverse Quark Momentum
Rohit Dhir; R. C. Verma
2009-01-08
We present a detailed analysis of the Bc form factors in the BSW framework, by investigating the effects of the flavor dependence on the average transverse quark momentum inside a meson. Branching ratios of two body decays of Bc meson to pseudoscalar and vector mesons are predicted.
System size and energy dependence of $?$ meson production at RHIC
J. H. Chen
2008-04-28
We present a system size and energy dependence of $\\phi$ meson production in Cu+Cu and Au+Au collisions at $\\sqrt{s_{NN}}$=62.4 GeV and 200 GeV measured by the STAR experiment at RHIC. We find that the number of participant scaled $\\phi$ meson yields in heavy ion collisions over that of p+p collisions are larger than 1 and increase with collision energy. We compare the results with those of open-strange particles and discuss the physics implication.
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.
Decays of Charmed Mesons to PV Final States
Bhubanjyoti Bhattacharya; Jonathan L. Rosner
2008-12-16
New data on the decays of the charmed particles $D^0$, $D^+$, and $D_s$ to $PV$ final states consisting of a light pseudoscalar meson $P$ and a light vector meson $V$ are analyzed. Following the same methods as in a previous analysis of $D \\to PP$ decays, one can test flavor symmetry, extract key key amplitudes, and obtain information on relative strong phases. Analyses are performed for Cabibbo-favored decays and then extended to predict properties of singly- and doubly-Cabibbo-suppressed processes.
Meson production in high-energy electron-nucleus scattering
Göran Fäldt
2010-06-09
Experimental studies of meson production through two-photon fusion in inelastic electron-nucleus scattering is now under way. A high-energy photon radiated by the incident electron is fused with a soft photon radiated by the nucleus. The process takes place in the small-angle-Coulomb region of nuclear scattering. We expound the theory for this production process as well as its interference with coherent-radiative-meson production. In particular, we investigate the distortion of the electron wave function due to multiple-Coulomb scattering.
Neutron Stars with a Stable, Light Supersymmetric Baryon
Shmuel Balberg; Glennys R. Farrar; Tsvi Piran
2001-04-10
If a light gluino exists, the lightest gluino-containing baryon, the \\OSO, is a possible candidate for self-interacting dark matter. In this scenario, the simplest explanation for the observed ratio $\\Omega_{dm}/\\Omega_b \\approx 6-10$ is that $m_{S^0} \\sim 900$\\MeVcs; this is not at present excluded by particle physics. Such an \\OSO could be present in neutron stars, with hyperon formation serving as an intermediate stage. We calculate equilibrium compositions and equation of state for high density matter with the \\OSO, and find that for a wide range of parameters the properties of neutron stars with the \\OSO are consistent with observations. In particular, the maximum mass of a nonrotating star is $1.7-1.8 M_\\odot$, and the presence of the \\OSO is helpful in reconciling observed cooling rates with hyperon formation.
Tree Level Metastability and Gauge Mediation in Baryon Deformed SQCD
Barnard, James
2009-01-01
We investigate supersymmetric QCD with gauge group SU(2) and a baryon deformation to the superpotential. The existence of an uplifted vacuum at the origin with tree level metastability is demonstrated. When this model is implemented in a direct gauge mediation scenario we therefore find gaugino masses which are comparable to sfermion masses and parameterised by an effective number of messengers 1/8. All deformations are well motivated by appealing to the electric theory and an R-symmetry. This R-symmetry is explicitly broken by the same term responsible for supersymmetry breaking. Moreover, the model does not suffer from the Landau pole problem and we find that it can be described in terms of just two scales: the weak scale and a high scale like the Planck or GUT scale. The model can be tested by searching for new particles at the TeV scale charged under the visible sector gauge group.
Tree Level Metastability and Gauge Mediation in Baryon Deformed SQCD
James Barnard
2010-02-15
We investigate supersymmetric QCD with gauge group SU(2) and a baryon deformation to the superpotential. The existence of an uplifted vacuum at the origin with tree level metastability is demonstrated. When this model is implemented in a direct gauge mediation scenario we therefore find gaugino masses which are comparable to sfermion masses and parameterised by an effective number of messengers 1/8. All deformations are well motivated by appealing to the electric theory and an R-symmetry. This R-symmetry is explicitly broken by the same term responsible for supersymmetry breaking. Moreover, the model does not suffer from the Landau pole problem and we find that it can be described in terms of just two scales: the weak scale and a high scale like the Planck or GUT scale. The model can be tested by searching for new particles at the TeV scale charged under the visible sector gauge group.
Electric-Magnetic Struggle in QGP, Deconfinement and Baryons
Edward Shuryak
2007-09-13
We argue that quite unusual properties of Quark-Gluon Plasma in the RHIC temperature domain $T=(1-2)T_c$ are consequences of the approximate equilibrium between electric and magnetic sectors reached above the deconfinement temperature. Already classical study of few body motion in a electric-magnetic plasma shows abnormally large scattering rate due to the so called ``magnetic bottle'' effect. Molecular dynamics simulation have found that equal mixture of electric and magnetic quasiparticles do produce plasmas of small viscosity and even smaller diffusion rate, comparable to what is needed to explain RHIC data and also to what follows from AdS/CFT. As a separate issue, we point out that right above $T_c$ there should be surviving s-wave baryons made of quarks ($N,\\Delta$), as well as adjoint objects, 3-gluon and 3-monopole chains (the latter being nothing else but ``calorons'' or finite-T instantons).
On the Condensed Matter Analog of Baryon Chiral Perturbation Theory
Bruegger, C.; Moser, M.; Wiese, U.-J.; Hofmann, C. P.; Kaempfer, F.; Pepe, M.
2009-04-20
It is shown that baryon chiral perturbation theory, i.e., the low-energy effective theory for pions and nucleons in quantum chromodynamics, has its condensed matter analog: A low-energy effective theory describing magnons as well as holes (or electrons) doped into antiferromagnets. We briefly present a symmetry analysis of the Hubbard and t-J-type models, and review the construction of the leading terms in the effective Lagrangian. As a nontrivial application we study different phases of hole- and electron-doped antiferromagnets--in particular, we investigate whether a so-called spiral phase with an inhomogeneous staggered magnetization (order parameter) may be stable. We would like to emphasize that the effective theory is universal and makes model-independent predictions for a large class of systems, whereas the material-specific properties enter the effective theory only through the numerical values of a few low-energy parameters.
Study of flavor-tagged baryon production in B decay
Baringer, Philip S.
1997-01-01
ARTICLES Study of flavor-tagged baryon production in B decay R. Ammar, 1 P. Baringer, 1 A. Bean, 1 D. Besson, 1 D. Coppage, 1 N. Copty, 1 R. Davis, 1 N. Hancock, 1 S. Kotov, 1 I. Kravchenko, 1 N. Kwak, 1 Y. Kubota, 2 M. Lattery, 2 J. K. Nelson, 2 S..., 4 K. Honscheid, 4 H. Kagan, 4 R. Kass, 4 J. Lee, 4 M. Sung, 4 C. White, 4 R. Wanke, 4 A. Wolf, 4 M. M. Zoeller, 4 X. Fu, 5 B. Nemati, 5 W. R. Ross, 5 P. Skubic, 5 M. Wood, 5 M. Bishai, 6 J. Fast, 6 E. Gerndt, 6 J. W. Hinson, 6 T. Miao, 6 D. H. Miller...
ContentsContents3399the normal distribution
Vickers, James
ContentsContents3399the normal distribution 1. The normal distribution 2. The normal approximation to the binomial distribution 3. Sums and differences of random variables Learning outcomes In a previous Workbook of a continuous random variables: the normal distribution. The probabilities of the normal distribution have
ContentsContents4343Regression and correlation
Vickers, James
ContentsContents4343Regression and correlation 1. Regression 2. Correlation Learning outcomes You. 1 #12;Regression 43.1 Introduction Problems in engineering often involve the exploration of the relationship(s) between two or more variables. The technique of regression analysis is very useful and well
ContentsContents1133integration integration
Vickers, James
ContentsContents1133integration integration 1. Basic concepts of integration 2. Definite integrals 3. The area bounded by a curve 4. Integration by parts 5. Integration by substitution and using partial fractions 6. Integration of trigonometric functions Learning outcomes In this workbook you
The $\\sigma, f_0(980)$ and $a_0(980)$ resonances in $J/\\psi\\to N {\\bar N}$ meson meson decays
Li, C; Vacas, M J V; Li, Chiangbing
2004-01-01
We study the four-body decays $J/\\psi\\to N {\\bar N}$ {\\it meson meson} using a chiral unitary approach. The calculation of the $J/\\psi\\to N \\bar N \\pi^+ \\pi^-$ process properly reproduces the experimental data taking the final state interaction (FSI) of mesons and the contribution of intermediate $\\rho$ meson into account. The isoscalar resonances $\\sigma$, $f_0(980)$ and the isovector resonance $a_0(980)$ are generated through the FSI of the mesons in the channels $J/\\psi\\to N \\bar N \\pi^0 \\pi^0$ and $J/\\psi\\to N \\bar N \\pi^0 \\eta$, respectively. We also calculate the two mesons invariant mass distribution and the partial decay width of $J/\\psi\\to N \\bar N K^+ K^-$ and $J/\\psi\\to N \\bar N K^0 {\\bar K}^0$, on which there is still no experimental data available.
Multi-strange baryon production in pp, p-Pb and Pb-Pb collisions measured with ALICE at the LHC
Didier Alexandre; for the ALICE Collaboration
2015-03-04
Multi-strange baryons are of particular interest in the understanding of particle production mechanisms, as their high strangeness content makes them susceptible to changes in the hadrochemistry of the colliding systems. In ALICE, these hyperons are reconstructed via the detection of their weak decay products, which are identified through their measured ionisation losses and momenta in the Time Projection Chamber. The production rates of charged $\\Xi$ and $\\Omega$ baryons in proton-proton (pp), proton-lead (p-Pb) and lead-lead (Pb-Pb) collisions are reported as a function of $p_{\\mathrm{T}}$. A direct comparison in the hyperon-to-pion ratios between the three collision systems is made as a function of event charged-particle multiplicity. The recently measured production rates in p-Pb interactions reveal an enhancement with increasing event multiplicity, consistent with a hierarchy dependent on the strangeness content of the hyperons. These results are discussed in the context of chemical equilibrium predictions, taking into account the extracted temperature parameter from a thermal model fit to the hadron yields in Pb-Pb data.
Measurements of the properties of ?c (2595), ?c (2625), ?c (2455), and ?c (2520) baryons
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T; Gonzalez, B Alvarez; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; et al
2011-07-13
We report measurements of the resonance properties of ?c(2595)+ and ?c(2595)+ baryons in their decays to ?c+?+?- as well as ?c(2455)++,0 and ?c(2455)++,0 baryons in their decays to ?c+?± final states. These measurements are performed using data corresponding to 5.2 fb-1 of integrated luminosity from pp? collisions at ?s = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. Exploiting the largest available charmed baryon sample, we measure masses and decay widths with uncertainties comparable to the world averages for ?c states, and significantly smaller uncertainties than the world averages for excited ?c+ states.
Energy Science and Technology Software Center (OSTI)
003241MLTPL00 Content Model Guidelines https://github.com/usgin/usginspecs/wiki/Content-Model-Guidelines
Coulomb gauge approach for charmonium meson and hybrid radiative transitions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gou, Peng; Yepez-Martínez, Tochtli; Szczepaniak, Adam P.
2015-01-22
We consider the lowest order interaction of the Foldy-Wouthuysen QED and QCD Hamiltonian in the Coulomb gauge approach, to describe radiative transitions between conventional and hybrids charmonium mesons. The results are compared to potential quark models and lattices calculations.
Photoproduction of Heavy Vector Mesons at the LHC
Joakim Nystrand
2005-03-23
The strong electromagnetic fields associated with high energy protons and nuclei may lead to exclusive photoproduction of vector mesons in proton-proton and nucleus-nucleus collisions at the LHC. This paper will discuss the expected cross sections and rapidity and transverse momentum distributions.
Meson production decreases with increasing proton beam emittance, but
McDonald, Kirk
Meson production decreases with increasing proton beam emittance, but careful optimization keeps production a Ga-jet target is then about 88% of that for a Hg-jet target. INFLUENCE OF PROTON BEAM EMITTANCES ON PARTICLE PRODUCTION OFF A MUON COLLIDER TARGET (IPAC13, TUPFI069) The geometric parameters of a free Hg
Hadronic matrix elements of neutral-meson mixing through lattice QCD
C. C. Chang
2015-09-23
Neutral-meson mixing is loop suppressed in the Standard Model, leading to the possibility of enhanced sensitivity to new physics. The uncertainty in Standard Model predictions for $B$-meson oscillation frequencies is dominated by theoretical uncertainties within the short-distance $B$-meson hadronic matrix elements, motivating the need for improved precision. In $D$-meson mixing, the Standard Model short-distance contributions are further suppressed by the GIM mechanism allowing for the possibility of large new physics enhancements. A first-principle determination of the $D$-meson short-distance hadronic matrix elements will allow for model-discrimination between the new physics theories. I review recently published and ongoing lattice calculations of hadronic matrix elements in $B$ and $D$-meson mixing with emphasis on the Fermilab lattice and MILC collaboration effort on the determination of the $B$ and $D$-meson mixing hadronic matrix elements using the methods of lattice QCD.
Formation of the intermediate baryon systems in hadron-nuclear and nuclear-nuclear interactions
M. K. Suleymanov; E. U. Khan; A Kravchakova; Mahnaz Q. Haseeb; S. M. Saleem; Y. H. Huseynaliyev; S Vokal; A. S. Vodopianov; O. B. Abdinov
2007-12-17
The centrality experiments indicate regime change and saturation in the behavior of some characteristics of the secondary particles emitted in hadron-nuclear and nuclear-nuclear interactions at high energies. The phenomenon has a critical character. The simple models do not explain the effect. We suppose that the responsible mechanism to explain the phenomenon could be the formation and decay of the intermediate baryon systems. Such systems could be formed as a result of nucleon percolation in compressed baryonic matter. Formation of big percolation cluster may change the properties of the medium, e.g., it could lead to the changing its transparency. This could be used to get a signal of the intermediate baryonic system formation. We consider two signals to identify the formation of the intermediate baryon systems: the critical changing of transparency of the strongly interacting matter and the enhancement of light nuclei production with increase in centrality.
Fluid dynamic propagation of initial baryon number perturbations on a Bjorken flow background
Floerchinger, Stefan
2015-01-01
Baryon number density perturbations offer a possible route to experimentally measure baryon number susceptibilities and heat conductivity of the quark gluon plasma. We study the fluid dynamical evolution of local and event-by-event fluctuations of baryon number density, flow velocity and energy density on top of a (generalised) Bjorken expansion. To that end we use a background-fluctuation splitting and a Bessel-Fourier decomposition for the fluctuating part of the fluid dynamical fields with respect to the azimuthal angle, the radius in the transverse plane and rapidity. We examine how the time evolution of linear perturbations depends on the equation of state as well as on shear viscosity, bulk viscosity and heat conductivity for modes with different azimuthal, radial and rapidity wave numbers. Finally we discuss how this information is accessible to experiments in terms of the transverse and rapidity dependence of correlation functions for baryonic particles in high energy nuclear collisions.
Measurement of the Bottom Baryon Resonances b C. Calancha (CIEMAT), J.P. Fernandez (CIEMAT),
Quigg, Chris
Measurement of the Bottom Baryon Resonances b and b C. Calancha (CIEMAT), J.P. Fernandez (CIEMAT), I. Gorelov (University of New Mexico), L. Labarga (CIEMAT), S. Seidel (University of New Mexico) CDF
Mass and magnetic dipole moment of negative parity heavy baryons with spin--3/2
Azizi, K
2015-01-01
We calculate the mass and residue of the heavy spin--3/2 negative parity baryons with single heavy bottom or charm quark by the help of a two-point correlation function. We use the obtained results to investigate the diagonal radiative transitions among the baryons under consideration. In particular, we compute corresponding transition form factors via light cone QCD sum rules which are then used to obtain the magnetic dipole moments of the heavy spin--3/2 negative parity baryons. We remove the pollutions coming from the positive parity spin--3/2 and positive/negative parity spin--1/2 baryons by constructing sum rules for different Lorentz structures. We compare the results obtained with the existing theoretical predictions.
Mass and magnetic dipole moment of negative parity heavy baryons with spin--3/2
K. Azizi; H. Sundu
2015-06-28
We calculate the mass and residue of the heavy spin--3/2 negative parity baryons with single heavy bottom or charm quark by the help of a two-point correlation function. We use the obtained results to investigate the diagonal radiative transitions among the baryons under consideration. In particular, we compute corresponding transition form factors via light cone QCD sum rules which are then used to obtain the magnetic dipole moments of the heavy spin--3/2 negative parity baryons. We remove the pollutions coming from the positive parity spin--3/2 and positive/negative parity spin--1/2 baryons by constructing sum rules for different Lorentz structures. We compare the results obtained with the existing theoretical predictions.
Emerging Non-Anomalous Baryonic Symmetries in the AdS_5/CFT_4 Correspondence
Nessi Benishti
2011-06-06
We study the breaking of baryonic symmetries in the AdS_5/CFT_4 correspondence for D3 branes at Calabi-Yau three-fold singularities. This leads, for particular VEVs, to the emergence of non-anomalous baryonic symmetries during the renormalization group flow. We claim that these VEVs correspond to critical values of the B-field moduli in the dual supergravity backgrounds. We study in detail the C^3/Z_3 orbifold, the cone over F_0 and the C^3/Z_5 orbifold. For the first two examples, we study the dual supergravity backgrounds that correspond to the breaking of the emerging baryonic symmetries and identify the expected Goldstone bosons and global strings in the infra-red. In doing so we confirm the claim that the emerging symmetries are indeed non-anomalous baryonic symmetries.
Monte Carlo simulation of baryon and lepton number violating processes at high energies
M. J. Gibbs; A. Ringwald; B. R. Webber; J. T Zadrozny
1994-06-09
We report results obtained with the first complete event generator for electroweak baryon and lepton number violating interactions at supercolliders. We find that baryon number violation would be very difficult to establish, but lepton number violation can be seen provided at least a few hundred L violating events are available with good electron or muon identification in the energy range 10 GeV to 1 TeV.
Remo Ruffini; Jay D. Salmonson; James R. Wilson; She-Sheng Xue
2000-04-18
The interaction of an expanding Pair-Electromagnetic pulse (PEM pulse) with a shell of baryonic matter surrounding a Black Hole with electromagnetic structure (EMBH) is analyzed for selected values of the baryonic mass at selected distances well outside the dyadosphere of an EMBH. The dyadosphere, the region in which a super critical field exists for the creation of electron-positron pairs, is here considered in the special case of a Reissner-Nordstrom geometry. The interaction of the PEM pulse with the baryonic matter is described using a simplified model of a slab of constant thickness in the laboratory frame (constant-thickness approximation) as well as performing the integration of the general relativistic hydrodynamical equations. The validation of the constant-thickness approximation, already presented in a previous paper Ruffini, et al.(1999) for a PEM pulse in vacuum, is here generalized to the presence of baryonic matter. It is found that for a baryonic shell of mass-energy less than 1% of the total energy of the dyadosphere, the constant-thickness approximation is in excellent agreement with full general relativistic computations. The approximation breaks down for larger values of the baryonic shell mass, however such cases are of less interest for observed Gamma Ray Bursts (GRBs). On the basis of numerical computations of the slab model for PEM pulses, we describe (i) the properties of relativistic evolution of a PEM pulse colliding with a baryonic shell; (ii) the details of the expected emission energy and observed temperature of the associated GRBs for a given value of the EMBH mass; 10^3 solar masses, and for baryonic mass-energies in the range 10^{-8} to 10^{-2} the total energy of the dyadosphere.
Cosmological implications of two types of baryon acoustic oscillation data
Hu, Yazhou; Li, Nan; Wang, Shuang
2015-01-01
Aims: We explore the cosmological implications of two types of baryon acoustic oscillation (BAO) data that are extracted by using the spherically averaged one-dimensional galaxy clustering (GC) statistics (hereafter BAO1) and the anisotropic two-dimensional GC statistics (hereafter BAO2), respectively. Methods: Firstly, making use of the BAO1 and the BAO2 data, as well as the SNLS3 type Ia supernovae sample and the Planck distance priors data, we constrain the parameter spaces of the $\\Lambda$CDM, the $w$CDM, and the Chevallier-Polarski-Linder (CPL) model. Then, we discuss the impacts of different BAO data on parameter estimation, equation of state $w$, figure of merit and deceleration-acceleration transition redshift. At last, we use various dark energy diagnosis, including Hubble diagram $H(z)$, deceleration diagram $q(z)$, statefinder hierarchy $\\{S^{(1)}_3, S^{(1)}_4\\}$, composite null diagnosic (CND) $\\{S^{(1)}_3, \\epsilon(z)\\}$ and $\\{S^{(1)}_4, \\epsilon(z)\\}$, to distinguish the differences between the...
Observation of the $\\Xi_b^0$ Baryon
Aaltonen, T.; Alvarez Gonzalez, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J.A.; Apresyan, A.; Arisawa, T.; /Waseda U. /Dubna, JINR
2011-07-01
The observation of the bottom, strange baryon {Xi}{sup 0}{sub b} through the decay chain {Xi}{sup 0}{sub b} {yields} {Xi}{sup +}{sub c} {pi}{sup -}, where {Xi}{sup +}{sub c} {yields} {Xi}{sup -} {pi}{sup +} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {yields} p {pi}{sup -}, is reported using data corresponding to an integrated luminosity of 4.2 ft{sup -1} from p{anti p} collisions at {radical}{ovr s} = 1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sup +5.6}{sub -5.4} candidates is observed whose probability of arising from a background fluctuation is 3.6 x 10{sup -12}, corresponding to 6.8 Gaussian standard deviations. The {Xi}{sup 0}{sub b} mass is measured to be 5787.8 {+-} 5.0(stat) {+-} 1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sup -}{sub b} is observed through the process {Xi}{sup -}{sub b} {yields} {Xi}{sup 0}{sub c} {pi}{sup -}, where {Xi}{sup 0}{sub c} {yields} {Xi}{sup -} {pi}{sup +}, {Xi}{sup -} {yields} {Lambda} {pi}{sup -}, and {Lambda} {yields} p {pi}{sup -}.
Two-Baryon Systems with Twisted Boundary Conditions
Zohreh Davoudi
2014-11-07
I derive the most general quantization condition for energy eigenvalues of two interacting baryons in a finite cubic volume when arbitrary twisted boundary conditions are imposed on their finite-volume wavefunctions. These quantization conditions are used, along with experimentally known scattering parameters of two-nucleon systems in the coupled 3S1-3D1 channels, to demonstrate the expected effect of a selection of twisted boundary conditions on the spectrum of the deuteron. It is shown that an order of magnitude reduction in the finite-volume corrections to the deuteron binding energy arise in moderate volumes with a proper choice of boundary conditions on the proton and the neutron, or by averaging the result of periodic and anti-periodic boundary conditions. These observations mean that a sub-percent accuracy can be achieved in the determination of the deuteron binding energy at (spatial) volumes as small as ~(9[fm])^3 in upcoming lattice QCD calculations of this nucleus with physical light-quark masses. The results reviewed in this talk are presented in details in Ref. [1].
Understanding WIMP-baryon interactions with direct detection: A Roadmap
Gluscevic, Vera
2014-01-01
We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to s...
Pulse Structure of Hot Electromagnetic Outflows with Embedded Baryons
Thompson, Christopher
2014-01-01
Gamma-ray bursts (GRBs) show a dramatic pulse structure that requires bulk relativistic motion, but whose physical origin has remained murky. We focus on a hot, magnetized jet that is emitted by a black hole and interacts with a confining medium. Strongly relativistic expansion of the magnetic field, as limited by a corrugation instability, may commence only after it forms a thin shell. Then the observed $T_{90}$ burst duration is dominated by the curvature delay, and null periods arise from angular inhomogeneities, not the duty cycle of the engine. We associate the $O(1)$ s timescale observed in the pulse width distribution of long GRBs with the collapse of the central 2.5-3$M_\\odot$ of a massive stellar core. A fraction of the baryons are shown to be embedded in the magnetized outflow by the hyper-Eddington radiation flux; they strongly disturb the magnetic field after the compactness drops below $\\sim 4\\times 10^3(Y_e/0.5)^{-1}$. The high-energy photons so created have a compressed pulse structure. Delayed...
Oh, Yongseok; Ko, Che Ming.
2009-01-01
The nuclear modification factor R(AA) of nonphotonic electrons in Au + Au collisions at root(S)NN = 200 GeV is studied by considering the decays of heavy-flavor hadrons produced in a quark coalescence model. Although an enhanced Lambda(c)/D(0) ratio...
Near-threshold Photoproduction of Phi Mesons from Deuterium
X. Qian; W. Chen; H. Gao; K. Hicks; K. Kramer; J. M. Laget; T. Mibe; Y. Qiang; S. Stepanyan; D. J. Tedeschi; W. Xu; K. P. Adhikari; M. Amaryan; M. Anghinolfi; J. Ball; M. Battaglieri; V. Batourine; I. Bedlinskiy; M. Bellis; A. S. Biselli; C. Bookwalter; D. Branford; W. J. Briscoe; W. K. Brooks; V. D. Burkert; S. L. Careccia; D. S. Carman; P. L. Cole; P. Collins; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; B. Dey; S. Dhamija; C. Djalali; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; P. Eugenio; S. Fegan; M. Y. Gabrielyan; N. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; W. Gohn; R. W. Gothe; L. Graham; K. A. Griffioen; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Hassall; M. Holtrop; Y. Ilieva; D. G. Ireland; S. S. Jawalkar; H. S. Jo; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F. J. Klein; P. Konczykowski; V. Kubarovsky; S. V. Kuleshov; V. Kuznetsov; K. Livingston; D. Martinez; M. Mayer; J. McAndrew; M. E. McCracken; B. McKinnon; C. A. Meyer; K. Mikhailov; T. Mineeva; M. Mirazita; V. Mokeev; B. Moreno; K. Moriya; B. Morrison; H. Moutarde; E. Munevar; P. Nadel-Turonski; A. Ni; S. Niccolai; I. Niculescu; M. R. Niroula; M. Osipenko; A. I. Ostrovidov; R. Paremuzyan; K. Park; S. Park; S. Anefalos Pereira; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; G. Ricco; M. Ripani; B. G. Ritchie; G. Rosner; P. Rossi; F. Sabatié; M. S. Saini; C. Salgado; D. Schott; R. A. Schumacher; E. Seder; H. Seraydaryan; Y. G. Sharabian; E. S. Smith; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; P. Stoler; I. I. Strakovsky; S. Strauch; M. Taiuti; C. E. Taylor; S. Tkachenko; M. Ungaro; B . Vernarsky; M. F. Vineyard; E. Voutier; L. B. Weinstein; D. P. Weygand; M. H. Wood; N. Zachariou; L. Zana; J. Zhang; B. Zhao; Z. W. Zhao
2010-12-14
We report the first measurement of the differential cross section on $\\phi$-meson photoproduction from deuterium near the production threshold for a proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson Lab. The measurement was carried out by a triple coincidence detection of a proton, $K^+$ and $K^-$ near the theoretical production threshold of 1.57 GeV. The extracted differential cross sections $\\frac{d\\sigma}{dt}$ for the initial photon energy from 1.65-1.75 GeV are consistent with predictions based on a quasifree mechanism. This experiment establishes a baseline for a future experimental search for an exotic $\\phi$-N bound state from heavier nuclear targets utilizing subthreshold/near-threshold production of $\\phi$ mesons.
Moments of $?$ meson spectral functions in vacuum and nuclear matter
Philipp Gubler; Wolfram Weise
2015-07-14
Moments of the $\\phi$ meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU(3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the $e^+ e^- \\to K^+ K^-$ cross section. In nuclear matter the $\\phi$ spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the $\\phi$ meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.
Neutral Meson Decays into Two Photons from Lattice QCD
Huey-Wen Lin; Saul D. Cohen
2013-02-04
A precision determination of the neutral-pion width would improve determinations of the splitting between the up- and down-quark masses, and matrix elements for the decay of neutral mesons into two photons could play a role in the attempt to probe beyond-the-Standard Model physics in muon $g-2$ experiments. The theoretical error is dominated by hadronic light-by-light diagrams, and since direct measurements are extremely difficult, model calculations factorize it into two-photon diagrams connected by the lightest hadrons. We employ perturbative techniques to express the photon as a superposition of QCD eigenstates accessible in lattice-QCD calculations and found that vector-meson dominance is a poor description of the two-photon decay process when both photons are off shell.
Testing the EPR Locality using B-Mesons
Tsubasa Ichikawa; Satoshi Tamura; Izumi Tsutsui
2008-07-03
We study the possibility of testing local realistic theory (LRT), envisioned implicitly by Einstein, Podolsky and Rosen in 1935, based on the Bell inequality for the correlations in the decay modes of entangled K or B-mesons. It is shown that such a test is possible for a restricted class of LRT, despite the passive nature of decay events and/or the non-unitary treatment of the correlations which invalidate the test for general LRT. Unfortunately, the present setup of the KEKB (Belle) experiment, where the coherence of entangled B-mesons has been confirmed recently, does not admit such a test due to the inability of determining the decay times of the entangled pairs separately. The indeterminacy also poses a problem for ensuring the locality of the test, indicating that improvement to resolve the indeterminacy is crucial for the test of LRT.
Observation of ?c1 Decays into Vector Meson Pairs ??, ?? and, ??
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; An, L.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; et al
2011-08-22
Using (106±4)×10? ?(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of ?c1 to vector meson pairs ??, ??, and ??. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for ?c1 ???, ??, and ??, respectively, which indicates that the hadron helicity selection rule is significantly violated in ?cJ decays. In addition, the measurement of ?cJ??? provides the first indication of the rate of doubly OZI-suppressed ?cJ decay. Finally, we present improved measurements for the branching fractions of ?c0 and ?c2 to vector meson pairs.
Nuclear symmetry energy in a modified quark meson coupling model
Mishra, R N; Panda, P K; Barik, N; Frederico, T
2015-01-01
We study nuclear symmetry energy and the thermodynamic instabilities of asymmetric nuclear matter in a self-consistent manner by using a modified quark-meson coupling model where the confining interaction for quarks inside a nucleon is represented by a phenomenologically averaged potential in an equally mixed scalar-vector harmonic form. The nucleon-nucleon interaction in nuclear matter is then realized by introducing additional quark couplings to $\\sigma$, $\\omega$, and $\\rho$ mesons through mean-field approximations. We find an analytic expression for the symmetry energy ${\\cal E}_{sym}$ as a function of its slope $L$. Our result establishes a linear correlation between $L$ and ${\\cal E}_{sym}$. We also analyze the constraint on neutron star radii in $(pn)$ matter with $\\beta$ equilibrium.
Finite volume effects for nucleon and heavy meson masses
Colangelo, Gilberto; Fuhrer, Andreas; Lanz, Stefan
2010-08-01
We apply the resummed version of the Luescher formula to analyze finite volume corrections to the mass of the nucleon and of heavy mesons. We show that by applying the subthreshold expansion of the scattering amplitudes one can express the finite volume corrections in terms of only a few physical observables and the size of the box. In the case of the nucleon, the available information about the quark mass dependence of these physical quantities is discussed and used to assess the finite volume corrections to the nucleon mass as a function of the quark mass including a detailed analysis of the remaining uncertainties. For heavy mesons, the Luescher formula is derived both fully relativistically and in a nonrelativistic approximation and a first attempt at a numerical analysis is made.
Yoshikazu Fujiwara; Kenji Fukukawa
2011-02-15
We solve the neutron-deuteron (nd) scattering in the Faddeev formalism, employing the NN sector of the quark-model baryon-baryon interaction fss2. The energy-dependence of the NN interaction, inherent to the resonating-group formulation of the quark-model baryon-baryon interaction, is eliminated by the standard off-shell transformation utilizing the normalization kernel of two-cluster systems. An extra nonlocality originating from this procedure is very important to reproduce all the nd scattering observables below E_n Green function is shown in detail, which is based on the spline function method originally developed by the Bochum-Krakow group. The predicted elastic differnetial cross sections reproduce the observed deep cross section minima at E_n=35-65 MeV and $\\theta_{c.m}=130^{\\circ}-135^{\\circ}$, which is consitent with the nearly correct triton binding energy predicted by fss2 without the three-body force.
Testing MEM with Diquark and thermal Meson Correlation Functions
I. Wetzorke; F. Karsch
2000-11-03
When applying the maximum entropy method (MEM) to the analysis of hadron correlation functions in QCD a central issue is to understand to what extent this method can distinguish bound states, resonances and continuum contributions to spectral functions. We discuss these issues by analyzing meson and diquark correlation functions at zero temperature as well as free quark anti-quark correlators. The latter test the applicability of MEM to high temperature QCD.
CP Violation in B Meson Decays: Experimental Results
Lanceri, Livio; /Trieste U. /INFN, Trieste
2005-08-30
CP violation is intimately connected with the puzzle of matter-antimatter asymmetry and baryogenesis. In the Standard Model of particle physics, the observed CP violation phenomena are accounted for by the Cabibbo-Kobayashi-Maskawa mechanism involving a phase in the quark mixing matrix. This paper is devoted to a review of the experimental status of CP violation in the decays of B mesons.
Correlations between D and Dbar mesons in high energy photoproduction
Erik E Gottschalk
2002-11-13
Over 7000 events containing a fully reconstructed D{bar D} pair have been extracted from data recorded by the FOCUS photoproduction experiment at Fermilab. Preliminary results from a study of correlations between D and {bar D} mesons are presented. Correlations are used to study perturbative QCD predictions and investigate non-perturbative effects. We also present a preliminary result on the production of {psi}(3770).
Static-light mesons on a dynamical anisotropic lattice
Justin Foley; Alan O Cais; Mike Peardon; Sinead M Ryan
2006-10-09
We present results for the spectrum of static-light mesons from Nf=2 lattice QCD. These results were obtained using all-to-all light quark propagators on an anisotropic lattice, yielding an improved signal resolution when compared to more conventional lattice techniques. In particular, we consider the inversion of orbitally-excited multiplets with respect to the `standard ordering', which has been predicted by some quark models.
Localization of the glueball and possible decuplets of tensor mesons
Michal Majewski
2015-04-16
We apply the vanishing exotic commutator (VEC) model to study the flavor properties of the light mesons. The study arose from conviction that these properties are insufficiently recognized while the huge amount of experimental observations collected during many decades gets silent. So we have much information but little knowledge. The confirmation of glueball existence may be a necessary step to get out of this situation. It is argued that the decuplet is a right place for seeking glueball - the glueball exists if the decuplet exists. The decuplet is understood as a mixed state of the glueball with $q\\bar{q}$ nonet. The VEC model predicts two kinds of the decuplets. We discuss the one which is a mixed state of the glueball with the ideal nonet $q\\bar{q}$ state. It satisfies the mass formula and restricts the masses more than another one. We find that the mass of the glueball-dominated isoscalar meson is located between the masses of the N and S-dominated ones. We examine two candidates for tensor decuplets. One of them refers to ancient hunting for glueball in the hope to explain anomalies of the nonet properties. For a long time it was considered as a nonet. We argue that this multiplet may be a decuplet whose nature was masked in unexpected way by the lack of room for glueball. However, according to recent data, room exists due to the discovery of anomalously large difference between the masses of neutral and charged components of the $K_2^*(1430)$ meson. Another decuplet candidate, lying above, accepts as a glueball-dominated state one of the $g_T$ mesons which were widely discussed few decades ago.
Production of $?$ and $?'$ Mesons on Nucleons and Nuclei
B. Krusche; C. Wilkin
2014-10-28
The production of $\\eta$ and $\\eta^{\\prime}$ mesons in photon- and hadron-induced reactions on free and quasi-free nucleons and on nuclei is reviewed. The extensive database on $\\gamma N \\to \\eta N$, for both proton and neutron targets, is described in detail and its implications for the search for $N^{\\star}$ resonances much heavier than the dominant $S_{11}(1535)$ discussed. Though less is currently known about the production of the $\\eta^{\\prime}$ or of $\\eta\\pi$ pairs, these also offer tantalizing prospects in the search for the missing isobars. The more limited data available on pion-induced production are still necessary ingredients in the partial wave analysis discussed. The production of the $\\eta$-meson in $pp$ and $pn$ collisions shows once again the strong influence of the $S_{11}(1535)$ isobar, which is in contrast to the relatively weak behaviour seen near threshold for $\\eta^{\\prime}$ production. This difference is reflected in the important final state interaction effects of the $\\eta$ in nuclei that may even lead to this meson being "bound" in some systems. The evidence for this is reviewed for both $\\gamma A$ and $p A$ collisions. The inclusive photoproduction of $\\eta$, $\\eta^{\\prime}$, and $\\eta\\pi$ pairs from nuclei provides further information regarding the production mechanism and the interaction of the $\\eta$ and $\\eta^{\\prime}$ with nuclei and the $\\eta\\pi$ pairs may even allow access to low mass $\\eta A$ systems that are forbidden in direct single-meson photoproduction.
Pseudoscalar Mesons in the SU(3) Linear Sigma Model with Gaussian Functional Approximation
Hua-Xing Chen; V. Dmitrasinovic; Hiroshi Toki
2010-04-13
We study the SU(3) linear sigma model for the pseudoscalar mesons in the Gaussian Functional Approximation (GFA). We use the SU(3) linear sigma model Lagrangian with nonet scalar and pseudo-scalar mesons including symmetry breaking terms. In the GFA, we take the Gaussian Ansatz for the ground state wave function and apply the variational method to minimize the ground state energy. We derive the gap equations for the dressed meson masses, which are actually just variational parameters in the GFA method. We use the Bethe-Salpeter equation for meson-meson scattering which provides the masses of the physical nonet mesons. We construct the projection operators for the flavor SU(3) in order to work out the scattering T-matrix in an efficient way. In this paper, we discuss the properties of the Nambu-Goldstone bosons in various limits of the chiral $U_L(3)\\times U_R(3)$ symmetry.
New Insights into the Coupling of $\\eta $ and $f_1$ Mesons to the Nucleon
Kirchbach, M; Neumeier, S; Kamalov, S S
1996-01-01
We show that the contact couplings of neutral pseudoscalar and axial mesons to the nucleon are proportional to $\\Delta s$, the fraction of nucleon spin carried by the strange quark sea, and thus are strongly suppressed relative to the couplings of charged mesons to the nucleon. On the other side, recent high accuracy data on $\\eta $ photoproduction at threshold reveal the need for non--negligibile $\\eta NN$ vertices, while fitting $\\bar N N$ phase shifts by means of effective meson exchange potentials requires a substantial presence of $f_1$ mesons there. We here advocate the idea to attribute the couplings of neutral pseudoscalar and axial vector mesons to effective triangular diagrams containig non--strange mesons and demonstrate its usefulness in describing available data.
Compact stars in a SU(3) Quark-Meson Model
Andreas Zacchi; Rainer Stiele; Juergen Schaffner-Bielich
2015-06-05
The recent observations of the massive pulsars PSR J1614-2230 and of PSR J0348+0432 with about two solar masses implies strong constraints on the properties of dense matter in the core of compact stars. Effective models of QCD aiming to describe neutron star matter can thereby be considerably constrained. In this context, a chiral quark-meson model based on a SU(3) linear $\\sigma$-model with a vacuum pressure and vector meson exchange is discussed in this work. The impact of its various terms and parameters on the equation of state and the maximum mass of compact stars are delineated to check whether pure quark stars with two solar masses are feasible within this approach. Large vector meson coupling constant and a small vacuum pressure allow for maximum masses of two or more solar masses. However, pure quark stars made of absolutely stable strange quark matter, so called strange stars, turn out to be restricted to a quite small parameter range.
Compact stars in a SU(3) Quark-Meson Model
Zacchi, Andreas; Schaffner-Bielich, Juergen
2015-01-01
The recent observations of the massive pulsars PSR J1614-2230 and of PSR J0348+0432 with about two solar masses implies strong constraints on the properties of dense matter in the core of compact stars. Effective models of QCD aiming to describe neutron star matter can thereby be considerably constrained. In this context, a chiral quark-meson model based on a SU(3) linear $\\sigma$-model with a vacuum pressure and vector meson exchange is discussed in this work. The impact of its various terms and parameters on the equation of state and the maximum mass of compact stars are delineated to check whether pure quark stars with two solar masses are feasible within this approach. Large vector meson coupling constant and a small vacuum pressure allow for maximum masses of two or more solar masses. However, pure quark stars made of absolutely stable strange quark matter, so called strange stars, turn out to be restricted to a quite small parameter range.
Exclusive Vector Meson Production in Relativistic Heavy Ion Collisions
Spencer Klein; Joakim Nystrand
1999-02-06
Exclusive vector meson production reactions such as $Au + Au \\to Au + Au + V$, where $V=\\rho, \\omega, \\phi$ or $J/\\psi$ can proceed through photon-Pomeron and photon-meson interactions. Photons from the electromagnetic field of one nucleus interact coherently with the other nucleus. Photonuclear cross sections are scaled from $\\gamma p$ data, and convoluted with the photon spectrum to find the exclusive rates. The cross sections at the RHIC and LHC heavy ion colliders are huge, 10% of the total hadronic cross section at RHIC, and 50% at LHC. These accelerators may be useful as vector meson factories. With iodine beams at RHIC, 640 $\\rho$ are produced each second (10^{10}/year); with calcium at the LHC the rate is 240 kHz. The $\\phi$ rates are 39 Hz at RHIC and 15 kHz at LHC, while the $J/\\psi$ rate is 0.3 Hz at RHIC and 780 Hz at the LHC. Because of the coherent couplings, the reactions kinematics are similar to coherent two-photon interactions; we discuss the interplay between the two reactions.
SCHOOLOFSCIENCE Table of Contents
Varela, Carlos
SCHOOLOFSCIENCE Table of Contents Degrees Offered and Associated Departments 330 Overview Environmental Science 403 Interdisciplinary Science 407 Multidisciplinary Science 409 The Darrin Fresh Water
Cosmological implications of baryon acoustic oscillation (BAO) measurements
Éric Aubourg; Stephen Bailey; Julian E. Bautista; Florian Beutler; Vaishali Bhardwaj; Dmitry Bizyaev; Michael Blanton; Michael Blomqvist; Adam S. Bolton; Jo Bovy; Howard Brewington; J. Brinkmann; Joel R. Brownstein; Angela Burden; Nicolás G. Busca; William Carithers; Chia-Hsun Chuang; Johan Comparat; Antonio J. Cuesta; Kyle S. Dawson; Timothée Delubac; Daniel J. Eisenstein; Andreu Font-Ribera; Jian Ge; J. -M. Le Goff; Satya Gontcho A Gontcho; J. Richard Gott III; James E. Gunn; Hong Guo; Julien Guy; Jean-Christophe Hamilton; Shirley Ho; Klaus Honscheid; Cullan Howlett; David Kirkby; Francisco S. Kitaura; Jean-Paul Kneib; Khee-Gan Lee; Dan Long; Robert H. Lupton; Mariana Vargas Magaña; Viktor Malanushenko; Elena Malanushenko; Marc Manera; Claudia Maraston; Daniel Margala; Cameron K. McBride; Jordi Miralda-Escudé; Adam D. Myers; Robert C. Nichol; Pasquier Noterdaeme; Sebastián E. Nuza; Matthew D. Olmstead; Daniel Oravetz; Isabelle Pâris; Nikhil Padmanabhan; Nathalie Palanque-Delabrouille; Kaike Pan; Marcos Pellejero-Ibanez; Will J. Percival; Patrick Petitjean; Matthew M. Pieri; Francisco Prada; Beth Reid; Natalie A. Roe; Ashley J. Ross; Nicholas P. Ross; Graziano Rossi; Jose Alberto Rubiño-Martín; Ariel G. Sánchez; Lado Samushia; Ricardo Tanausú Génova Santos; Claudia G. Scóccola; David J. Schlegel; Donald P. Schneider; Hee-Jong Seo; Erin Sheldon; Audrey Simmons; Ramin A. Skibba; Anže Slosar; Michael A. Strauss; Daniel Thomas; Jeremy L. Tinker; Rita Tojeiro; Jose Alberto Vazquez; Matteo Viel; David A. Wake; Benjamin A. Weaver; David H. Weinberg; W. M. Wood-Vasey; Christophe Yèche; Idit Zehavi; Gong-Bo Zhao
2015-10-09
We derive constraints on cosmological parameters and tests of dark energy models from the combination of baryon acoustic oscillation (BAO) measurements with cosmic microwave background (CMB) and Type Ia supernova (SN) data. We take advantage of high-precision BAO measurements from galaxy clustering and the Ly-alpha forest (LyaF) in the BOSS survey of SDSS-III. BAO data alone yield a high confidence detection of dark energy, and in combination with the CMB angular acoustic scale they further imply a nearly flat universe. Combining BAO and SN data into an "inverse distance ladder" yields a 1.7% measurement of $H_0=67.3 \\pm1.1$ km/s/Mpc. This measurement assumes standard pre-recombination physics but is insensitive to assumptions about dark energy or space curvature, so agreement with CMB-based estimates that assume a flat LCDM cosmology is an important corroboration of this minimal cosmological model. For open LCDM, our BAO+SN+CMB combination yields $\\Omega_m=0.301 \\pm 0.008$ and curvature $\\Omega_k=-0.003 \\pm 0.003$. When we allow more general forms of evolving dark energy, the BAO+SN+CMB parameter constraints remain consistent with flat LCDM. While the overall $\\chi^2$ of model fits is satisfactory, the LyaF BAO measurements are in moderate (2-2.5 sigma) tension with model predictions. Models with early dark energy that tracks the dominant energy component at high redshifts remain consistent with our constraints. Expansion history alone yields an upper limit of 0.56 eV on the summed mass of neutrino species, improving to 0.26 eV if we include Planck CMB lensing. Standard dark energy models constrained by our data predict a level of matter clustering that is high compared to most, but not all, observational estimates. (Abridged)
Understanding WIMP-baryon interactions with direct detection: A Roadmap
Vera Gluscevic; Annika H. G. Peter
2014-06-30
We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.
Understanding WIMP-baryon interactions with direct detection: a roadmap
Gluscevic, Vera; Peter, Annika H.G. E-mail: apeter@physics.osu.edu
2014-09-01
We study prospects of dark-matter direct-detection searches for probing non-relativistic effective theory for WIMP-baryon scattering. We simulate a large set of noisy recoil-energy spectra for different scattering scenarios (beyond the standard momentum-independent contact interaction), for Generation 2 and futuristic experiments. We analyze these simulations and quantify the probability of successfully identifying the operator governing the scattering, if a WIMP signal is observed. We find that the success rate depends on a combination of factors: the WIMP mass, the mediator mass, the type of interaction, and the experimental energy window. For example, for a 20 GeV WIMP, Generation 2 is only likely to identify the right operator if the interaction is Coulomb-like, and is unlikely to do so in any other case. For a WIMP with a mass of 200 GeV or higher, success is almost guaranteed. We also find that, regardless of the scattering model and the WIMP parameters, a single Generation 2 experiment is unlikely to successfully discern the momentum dependence of the underlying operator on its own, but prospects improve drastically when experiments with different target materials and energy windows are analyzed jointly. Furthermore, we examine the quality of parameter estimation and degeneracies in the multi-dimensional parameter space of the effective theory. We find in particular that the resulting WIMP mass estimates can be severely biased if data are analyzed assuming the standard (momentum-independent) operator while the actual operator has momentum-dependence. Finally, we evaluate the ultimate reach of direct detection, finding that the prospects for successful operator selection prior to reaching the irreducible backgrounds are excellent, if the signal is just below the current limits, but slim if Generation 2 does not report WIMP detection.
Alternative experimental evidence for chiral restoration in excited baryons
L. Ya. Glozman
2007-09-25
Given existing empirical spectral patterns of excited hadrons it has been suggested that chiral symmetry is approximately restored in excited hadrons at zero temperature/density (effective symmetry restoration). If correct, this implies that mass generation mechanisms and physics in excited hadrons is very different as compared to the lowest states. One needs an alternative and independent experimental information to confirm this conjecture. Using very general chiral symmetry arguments it is shown that strict chiral restoration in a given excited nucleon forbids its decay into the N \\pi channel. Hence those excited nucleons which are assumed from the spectroscopic patterns to be in approximate chiral multiplets must only "weakly" decay into the N \\pi channel, (f_{N^*N\\pi}/f_{NN\\pi})^2 << 1. However, those baryons which have no chiral partner must decay strongly with a decay constant comparable with f_{NN\\pi}. Decay constants can be extracted from the existing decay widths and branching ratios. It turnes out that for all those well established excited nucleons which can be classified into chiral doublets N_+(1440) - N_-(1535), N_+(1710) - N_-(1650), N_+(1720) - N_-(1700), N_+(1680) - N_-(1675), N_+(2220) - N_-(2250), N_+(?) - N_-(2190), N_+(?) - N_-(2600), the ratio is (f_{N^*N\\pi}/f_{NN\\pi})^2 ~ 0.1 or much smaller for the high-spin states. In contrast, the only well established excited nucleon for which the chiral partner cannot be identified from the spectroscopic data, N(1520), has a decay constant into the N\\pi channel that is comparable with f_{NN\\pi}. This gives an independent experimental verification of the chiral symmetry restoration scenario.
Yasumichi Aoki; Tomomi Ishikawa; Taku Izubuchi; Christoph Lehner; Amarjit Soni
2015-06-29
Neutral $B$ meson mixing matrix elements and $B$ meson decay constants are calculated. Static approximation is used for $b$ quark and domain-wall fermion formalism is employed for light quarks. The calculations are carried out on $2+1$ flavor dynamical ensembles generated by RBC/UKQCD Collaborations with lattice spacings $0.086$fm ($a^{-1}\\sim 2.3$GeV) and $0.11$fm ($1.7$GeV), and a fixed physical spatial volume of about $(2.7{\\rm fm})^3$. In the static quark action, link-smearings are used to improve the signal-to-noise ratio. We employ two kinds of link-smearings, HYP1 and HYP2, and their results are combined in taking the continuum limit. For the matching between the lattice and the continuum theory, one-loop perturbative $O(a)$ improvements are made to reduce discretization errors. As the most important quantity of this work, we obtain SU(3) breaking ratio $\\xi=1.208(60)$, where the error includes statistical and systematic one. (Uncertainty from infinite $b$ quark mass is not included.) We also find other neutral $B$ meson mixing quantities $f_B\\sqrt{\\hat{B}_B}=240(22)$MeV, $f_{B_s}\\sqrt{\\hat{B}_{B_s}}=290(22)$MeV, $\\hat{B}_B=1.17(22)$, $\\hat{B}_{B_s}=1.22(13)$ and $B_{B_s}/B_B=1.028(74)$, $B$ meson decay constants $f_B=219(17)$MeV, $f_{B_s}=264(19)$MeV and $f_{B_s}/f_B=1.193(41)$, in the static limit of $b$ quark, which do not include infinite $b$ quark mass uncertainty.
Phenomenology of semileptonic B-meson decays with form factors from lattice QCD
Du, Daping; Gottlieb, Steven; Kronfeld, A S; Laiho, J; Lunghi, E; Van de Water, R S; Zhou, Ran
2015-01-01
We study the exclusive semileptonic $B$-meson decays $B\\to K(\\pi)\\ell^+\\ell^-$, $B \\to K(\\pi)\
Phenomenology of semileptonic B-meson decays with form factors from lattice QCD
Daping Du; A. X. El-Khadra; Steven Gottlieb; A. S. Kronfeld; J. Laiho; E. Lunghi; R. S. Van de Water; Ran Zhou
2015-10-22
We study the exclusive semileptonic $B$-meson decays $B\\to K(\\pi)\\ell^+\\ell^-$, $B \\to K(\\pi)\
Matrix elements of heavy-light mesons from a fine lattice
A. Ali Khan; A. Al-Haydari; V. Braun; S. Collins; M. Goeckeler; G. N. Lacagnina; M. Panero; A. Schaefer; G. Schierholz
2009-01-07
Results on semileptonic decay matrix elements of heavy-light mesons and charmonium spectrum and decay constant using a fine quenched lattice are presented.
Wave functions and decay constants of $B$ and $D$ mesons in the relativistic potential model
Mao-Zhi Yang
2012-01-30
With the decay constants of $D$ and $D_s$ mesons measured in experiment recently, we revisit the study of the bound states of quark and antiquark in $B$ and $D$ mesons in the relativistic potential model. The relativistic bound state wave equation is solved numerically. The masses, decay constants and wave functions of $B$ and $D$ mesons are obtained. Both the masses and decay constants obtained here can be consistent with the experimental data. The wave functions can be used in the study of $B$ and $D$ meson decays.
Nuclear Modification Factors of phi Mesons in d+Au, Cu+Cu and Au+Au Collisions at s_NN = 200 GeV
Adare, A. [University of Colorado, Boulder; Awes, Terry C [ORNL; Cianciolo, Vince [ORNL; Efremenko, Yuri [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Enokizono, Akitomo [Oak Ridge National Laboratory (ORNL); Read Jr, Kenneth F [ORNL; Silvermyr, David O [ORNL; Sorensen, Soren P [University of Tennessee, Knoxville (UTK); Stankus, Paul W [ORNL; PHENIX, Collaboration [The
2011-01-01
The PHENIX experiment at the Relativistic Heavy Ion Collider has performed systematic measurements of {phi} meson production in the K{sup +}K{sup -} decay channel at midrapidity in p+p, d+Au, Cu+Cu, and Au+Au collisions at {radical}s{sub NN} = 200 GeV. Results are presented on the {phi} invariant yield and the nuclear modification factor R{sub AA} for Au+Au and Cu+Cu, and R{sub dA} for d+Au collisions, studied as a function of transverse momentum (1 < p{sub T} < 7 GeV/c) and centrality. In central and midcentral Au+Au collisions, the R{sub AA} of {phi} exhibits a suppression relative to expectations from binary scaled p+p results. The amount of suppression is smaller than that of the {pi}{sup 0} and the {eta} in the intermediate p{sub T} range (2-5 GeV/c), whereas, at higher p{sub T}, the {phi}, {pi}{sup 0}, and {eta} show similar suppression. The baryon (proton and antiproton) excess observed in central Au+Au collisions at intermediate p{sub T} is not observed for the {phi} meson despite the similar masses of the proton and the {phi}. This suggests that the excess is linked to the number of valence quarks in the hadron rather than its mass. The difference gradually disappears with decreasing centrality, and, for peripheral collisions, the R{sub AA} values for both particle species are consistent with binary scaling. Cu+Cu collisions show the same yield and suppression as Au+Au collisions for the same number of N{sub part}. The R{sub dA} of {phi} shows no evidence for cold nuclear effects within uncertainties.
Aslaksen, Helmer
THE APPLICATIONS AND VALIDITY OF BODE'S LAW CAN WE EXPLAIN BODE'S LAW USING GRAVITY? 8 Law of Gravitation 8 Centre#12;#12;CONTENTS CONTENTS PAGE INTRODUCTION WHO, HOW AND WHEN IS THE BODE'S LAW DISCOVERED? 1 THE BODE'S LAW HOW THE BODE'S LAW SATISFIED URANUS 3 HOW THE BODE'S LAW LED TO THE DISCOVERY OF CERES
Constituent-quark model description of triply heavy-baryon nonperturbative lattice QCD data
Vijande, J; Garcilazo, H
2015-01-01
This paper provides results for the spectra of triply charmed and bottom baryons based on a constituent quark model approach. We take advantage of the assumption that potential models are expected to describe triply heavy baryons to a similar degree of accuracy as the successful results obtained in the charmonium and bottomonium sectors. The high precision calculation of the ground state and positive and negative parity excited states recently reported by nonperturbative lattice QCD provides us with a unique opportunity to confront model predictions with data. This comparison may also help to build a bridge between two difficult to reconcile lattice QCD results, namely, the lattice SU(3) QCD static three-quark potential and the recent results of nonperturbative lattice QCD for the triply heavy-baryon spectra.
The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory
Calle Cordon, Alvaro C. [JLAB; DeGrand, Thomas A. [University of Colorado; Goity, Jose L. [JLAB
2014-07-01
Baryon masses at varying values of Nc and light quark masses are studied with Lattice QCD and the results are analyzed in a low energy effective theory based on a combined framework of the 1/Nc and Heavy Baryon Chiral Perturbation Theory expansions. Lattice QCD results for Nc=3, 5 and 7 obtained in quenched calculations, as well as results for unquenched calculations for Nc=3, are used for the analysis. The results are consistent with a previous analysis of Nc=3 LQCD results, and in addition permit the determination of sub-leading in 1/Nc effects in the spin-flavor singlet component of the baryon masses as well as in the hyperfine splittings.
Constituent-quark model description of triply heavy-baryon nonperturbative lattice QCD data
J. Vijande; A. Valcarce; H. Garcilazo
2015-07-14
This paper provides results for the spectra of triply charmed and bottom baryons based on a constituent quark model approach. We take advantage of the assumption that potential models are expected to describe triply heavy baryons to a similar degree of accuracy as the successful results obtained in the charmonium and bottomonium sectors. The high precision calculation of the ground state and positive and negative parity excited states recently reported by nonperturbative lattice QCD provides us with a unique opportunity to confront model predictions with data. This comparison may also help to build a bridge between two difficult to reconcile lattice QCD results, namely, the lattice SU(3) QCD static three-quark potential and the recent results of nonperturbative lattice QCD for the triply heavy-baryon spectra.
On Productions of Net-baryons in Central Au-Au Collisions at RHIC Energies
Chen, Ya-Hui; Liu, Fu-Hu
2015-01-01
The transverse momentum and rapidity distributions of net-baryons (baryons minus anti-baryons) produced in central gold-gold (Au-Au) collisions at 62.4 and 200 GeV are analyzed in the framework of a multisource thermal model. Each source in the model is described by the Tsallis statistics to extract the effective temperature and entropy index from the transverse momentum distribution. The two parameters are used as input to describe the rapidity distribution and to extract the rapidity shift and contribution ratio. Then, the four types of parameters are used to structure some scatter plots of the considered particles in some three-dimensional (3D) spaces at the stage of kinetic freeze-out, which are expected to show different characteristics for different particles and processes. The related methodology can be used in the analyzes of particle production and event holography, which are useful for us to better understand the interacting mechanisms.
HERBVI - a program for simulation of baryon- and lepton- number violating processes
M. J. Gibbs; B. R. Webber
1995-04-05
We describe a Monte Carlo event generator for the simulation of baryon- and lepton-number violating processes at supercolliders. The package, {\\HERBVI}, is designed as a hard-process generator interfacing to the general hadronic event simulation program {\\HW}. In view of the very high multiplicity of gauge bosons expected in such processes, particular attention is paid to the efficient generation of multiparticle phase space. The program also takes account of the expected colour structure of baryon-number violating vertices, which has important implications for the hadronization of the final state.
Uplifting the baryonic branch: a test for backreacting anti-D3-branes
Anatoly Dymarsky; Stefano Massai
2013-09-30
Placing D3 or anti-D3-branes at the tip of the Klebanov-Strassler background results in uplifting the baryonic branch of the moduli space of the dual field theory. In this paper we derive a mass formula for the scalar particle associated with the motion along the baryonic branch, from both open and closed string points of view. We show that both methods give the same mass at linear order in number of (anti)D3-branes, thus providing a comprehensive check for the recently found linearized supergravity solution describing backreacting anti-D3-branes at the tip.
Dilepton as a Possible Signature for the Baryon-Rich Quark-Gluon Plasma
Xia, L. H.; Ko, Che Ming; Li, C. T.
1990-01-01
VOLUME 41, NUMBER 2 FEBRUARY 1990 Dilepton as a possible signature for the baryon-rich quark-gluon plasma L. H. Xia, ' C. M. Ko, and C. T. Li Cyclotron Institute and Center for Theoretical Physics, Texas A&M University, College Station, Texas 77843... at invariant masses between 2m?and 1 GeV. The total dilepton yield in this invariant mass region increases with the incident energy of the collision, but a saturation is seen once a baryon-rich quark-gluon plasma is formed in the initial stage. I...
SELEX: Recent Progress in the Analysis of Charm-Strange and Double-Charm Baryons
Engelfried, Jurgen
2007-02-01
SELEX (Fermilab Experiment 781) [1] employs beams of {Sigma}{sup -}, {pi}{sup -}, and protons at around 600 GeV/c to study production and decay properties of charmed baryons. It took data in the 1996/7 fixed target run and is currently analyzing those data. Here they focus on recently obtained results concerning the {Omega}{sub c}{sup 0} lifetime and the doubly-charmed baryons {Xi}{sub cc}{sup +} and {Xi}{sub cc}{sup ++}.
Composite Fermion Approach to Diquark and Heavy-Light Baryon Masses
Chandra, A; Chakrabarti, B
2013-01-01
A composite Fermion (CF) model of quasi particle has been used to describe a diquark. Considering baryons in quark-diquark configuration,the masses of the heavy light baryons like $\\Lambda_{c}^{+}$, $\\Sigma_{c}^{+}$, $\\Xi_{c}^{0}$, $\\Omega_{c}^{0}$ and $\\Lambda_{b}^{+}$, $\\Sigma_{b}^{+}$, $\\Xi_{b}^{0}$, $\\Omega_{b}^{-}$ have been computed using this CF model of the diquark. The results are found to be in good agreement with the corresponding experimental findings. It has been suggested that the diquark can be well described in the framework of CF model in a gauge invariant way.
Further Evidence of Narrow Baryonic Structures with Hadronic as Well as Leptonic Probes
B. Tatischeff; E. Tomasi-Gustafsson
2004-11-22
Although extracted from several experiments using hadronic probes \\cite{bor1}, narrow baryonic structures have been sometimes met with disbelief. New signatures are presented, which appear from already published data, obtained with hadronic probes as well as with leptonic probes. The authors of these results did not take into account the possibility to associate the discontinuities of their spectra with the topic of narrow baryonic low mass structures. The stability of the observed narrow structure masses, represents a confirmation of their genuine existence.
An Enquiry Concerning Charmless Semileptonic Decays of Bottom Mesons
Chaisanguanthum, Kris Somboon; /Harvard U. /SLAC
2008-09-19
The branching fractions for the decays B {yields} P{ell}{nu}{sub {ell}}, where P are the pseudoscalar charmless mesons {pi}{sup {+-}}, {pi}{sup 0}, {eta} and {eta}{prime} and {ell} is an electron or muon, are measured with B{sup 0} and B{sup {+-}} mesons found in the recoil of a second B meson decaying as B {yields} D{ell}{nu}{sub {ell}} or B {yields} D*{ell}{nu}{sub {ell}}. The measurements are based on a data set of 348 fb{sup -1} of e{sup +}e{sup -} collisions at {radical}s = 10.58 GeV recorded with the BABAR detector. Assuming isospin symmetry, measured pionic branching fractions are combined into {Beta}(B{sup 0} {yields} {pi}{sup -}{ell}{sup +}{nu}{sub {ell}}) = (1.54 {+-} 0.17{sub (stat)} {+-} 0.09{sub (syst)}) x 10{sup -4}. First evidence of the B{sup +} {yields} {eta}{ell}{sup +}{nu}{sub {ell}} decay is seen; its branching fraction is measured to be {Beta}(B{sup +} {yields} {eta}{ell}{sup +}{nu}{sub {ell}}) = (0.64 {+-} 0.20{sub (stat)} {+-} 0.03{sub (syst)}) x 10{sup -4}. It is determined that {Beta}(B{sup +} {yields} {eta}{prime}{ell}{sup +}{nu}{sub {ell}}) < 0.47 x 10{sup -4} to 90% confidence. Partial branching fractions for the pionic decays in ranges of the momentum transfer and various published calculations of the B {yields} {pi} hadronic form factor are used to obtain values of the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V{sub ub} between 3.61 and 4.07 x 10{sup -3}.
Hwang, D S; Ne'eman, Yuval
1994-01-01
BRST quantization of SU(2/1) electro-weak theory in the superconnection approach - and the Higgs meson mass
Using COSY-11 apparatus for the precise studies of the natural width of the eta prime meson
E. Czerwinski; P. Moskal
2007-10-17
We present preliminary results and motivation of measurement of the total width of the eta prime meson.
Bounds on R-parity violating supersymmetric couplings from leptonic and semileptonic meson decays
Dreiner, H. K.; Kraemer, M.; O'Leary, Ben [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany); Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany); S.U.P.A., School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom) and Institut fuer Theoretische Physik E, RWTH Aachen, 52056 Aachen (Germany)
2007-06-01
We present a comprehensive update of the bounds on R-parity violating supersymmetric couplings from lepton-flavor- and lepton-number-violating decay processes. We consider {tau} and {mu} decays as well as leptonic and semileptonic decays of mesons. We present several new bounds resulting from {tau}, {eta}, and kaon decays and correct some results in the literature concerning B meson decays.
Study of the production mechanism of the eta meson by means of analysing power measurements
R. Czyzykiewicz; P. Moskal; H. -H. Adam; A. Budzanowski; E. Czerwinski; D. Gil; D. Grzonka; M. Janusz; L. Jarczyk; B. Kamys; A. Khoukaz; P. Klaja; B. Lorentz; J. Majewski; W. Oelert; C. Piskor-Ignatowicz; J. Przerwa; J. Ritman; H. Rohdjess; T. Rozek; T. Sefzick; M. Siemaszko; J. Smyrski; A. Taeschner; K. Ulbrich; P. Winter; M. Wolke; P. Wuestner; W. Zipper
2006-09-13
Information about the production mechanism of the eta meson in proton-proton collisions can be inferred by confronting the experimental studies on the analysing power for the p(pol)p --> pp eta reaction with the theoretical predictions of this observable. Results show that the predictions of pure pseudoscalar- or vector meson exchange model are insufficient to describe the analysing powers.
Study of the production mechanism of the eta meson by means of analysing power measurements
Czyzykiewicz, R; Adam, H H; Budzanowski, A; Czerwinski, E; Gil, D; Grzonka, D; Janusz, M; Jarczyk, L; Kamys, B; Khoukaz, A; Klaja, P; Lorentz, B; Majewski, J; Oelert, W; Piskor-Ignatowicz, C; Przerwa, J; Ritman, J; Rohdjess, H; Rozek, T; Sefzick, T; Siemaszko, M; Smyrski, J; Täschner, A; Ulbrich, K; Winter, P; Wolke, M; Wüstner, P; Zipper, W
2007-01-01
Information about the production mechanism of the eta meson in proton-proton collisions can be inferred by confronting the experimental studies on the analysing power for the p(pol)p --> pp eta reaction with the theoretical predictions of this observable. Results show that the predictions of pure pseudoscalar- or vector meson exchange model are insufficient to describe the analysing powers.
Meson Production Comparison between HG and GA at 8 GeV
McDonald, Kirk
optimization (0.5cm/67mrad/33 mrad) 57340 (Pos) 60791 (Neg) 118131 (Sum) 46414 (Pos) 48830 (Neg) 95244 (Sum) Meson Production after optimization 61255 (Pos) 66996 (Neg) 128351 (Sum) (16.6% higher than GA case) 54129 (Pos) 55958 (Neg) 110087 (Sum) 53253 (Pos) 54091 (Neg) 107343 (Sum) #12;Meson Production
Effects of (N)over-Barn Polarization on Vector-Meson Masses at Finite-Temperature
Song, C. S.; Xia, P. W.; Ko, Che Ming.
1995-01-01
Effects of (N) over bar N polarization on vector meson (rho and omega) masses at finite temperature are studied. Including a reduced nucleon mass in a hot matter, we find that the reduction of vector meson masses due to the vacuum effect is larger...
Study of CP Asymmetry in the Neutral B Meson Decays to Two Charged Pions
Aihara, Hiroaki
Study of CP Asymmetry in the Neutral B Meson Decays to Two Charged Pions Nakadaira Takeshi 1 December 2002 1 nakadair@hep.phys.s.uÂtokyo.ac.jp #12; Abstract We present the measurement of CP Âviolating as a B 0 # # + # - CP eigenstate and identify the flavor of the accompanying B meson from its decay
Study of CP Asymmetry in the Neutral B Meson Decays to Two Charged Pions
Aihara, Hiroaki
Study of CP Asymmetry in the Neutral B Meson Decays to Two Charged Pions Nakadaira Takeshi1 December 2002 1 nakadair@hep.phys.s.u-tokyo.ac.jp #12;Abstract We present the measurement of CP + - CP eigenstate and identify the flavor of the accompanying B meson from its decay products. From
Search for CP Violation in D± Meson Decays to ??±
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Stari?, M.; Aihara, H.; Arinstein, K.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bay, A.; Bhardwaj, V.; Bhuyan, B.; Bozek, A.; Bra?ko, M.; Browder, T. E.; Chen, A.; Chen, P.; Cheon, B. G.; Chilikin, K.; Chistov, R.; Cho, I.-S.; Cho, K.; Choi, Y.; Doležal, Z.; Drásal, Z.; Eidelman, S.; Fast, J. E.; Gaur, V.; Gabyshev, N.; Golob, B.; Haba, J.; Hayasaka, K.; Horii, Y.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Iijima, T.; Inami, K.; Ishikawa, A.; Itoh, R.; Iwabuchi, M.; Iwasaki, Y.; Iwashita, T.; Julius, T.; Kang, J. H.; Kawasaki, T.; Kiesling, C.; Kim, H. J.; Kim, H. O.; Kim, J. B.; Kim, K. T.; Kim, M. J.; Kim, Y. J.; Kinoshita, K.; Ko, B. R.; Kobayashi, N.; Koblitz, S.; Kodyš, P.; Korpar, S.; Križan, P.; Kumita, T.; Kwon, Y.-J.; Lange, J. S.; Lee, S.-H.; Li, J.; Li, Y.; Libby, J.; Liu, C.; Liu, Z. Q.; Louvot, R.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mohanty, G. B.; Nakano, E.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Nozaki, T.; Ohshima, T.; Okuno, S.; Olsen, S. L.; Pakhlova, G.; Park, H. K.; Park, K. S.; Pestotnik, R.; Petri?, M.; Piilonen, L. E.; Röhrken, M.; Ryu, S.; Sahoo, H.; Sakai, K.; Sakai, Y.; Sanuki, T.; Schneider, O.; Schwanda, C.; Schwartz, A. J.; Seon, O.; Sevior, M. E.; Shebalin, V.; Shen, C. P.; Shibata, T.-A.; Shiu, J.-G.; Shwartz, B.; Simon, F.; Smerkol, P.; Sohn, Y.-S.; Sokolov, A.; Stani?, S.; Sumihama, M.; Sumisawa, K.; Tatishvili, G.; Teramoto, Y.; Trabelsi, K.; Uchida, M.; Uehara, S.; Uglov, T.; Unno, Y.; Uno, S.; Urquijo, P.; Varner, G.; Vossen, A.; Wang, C. H.; Wang, M.-Z.; Watanabe, M.; Watanabe, Y.; Williams, K. M.; Won, E.; Yabsley, B. D.; Yamashita, Y.; Yuan, C. Z.; Zhang, C. C.; Zhang, Z. P.; Zhilich, V.; Zhulanov, V.; Zupanc, A.
2012-02-01
We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D±?K?K??± and the Cabibbo-favored decays D±s?K?K??± in the K?K? mass region of the ? resonance. Using 955 fb?¹ of data collected with the Belle detector, we obtain AD?????CP=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.
Double vector meson production in the International Linear Collider
F. Carvalho; V. P. Goncalves; B. D. Moreira; F. S. Navarra
2015-04-17
In this paper we study double vector meson production in $\\gamma \\gamma$ interactions at high energies and, using the color dipole picture, estimate the main observables which can be probed at the International Linear Collider (ILC). The total $\\gamma (Q_1^2) + \\gamma (Q_2^2) \\rightarrow V_1 + V_2$ cross-sections for $V_i = \\rho$, $\\phi$, $J/\\psi$ and $\\Upsilon$ are computed and the energy and virtuality dependencies are studied in detail. Our results demonstrate that the experimental analysis of this process is feasible at the ILC and it can be useful to constrain the QCD dynamics at high energies.
Double vector meson production in the International Linear Collider
Carvalho, F; Moreira, B D; Navarra, F S
2015-01-01
In this paper we study double vector meson production in $\\gamma \\gamma$ interactions at high energies and, using the color dipole picture, estimate the main observables which can be probed at the International Linear Collider (ILC). The total $\\gamma (Q_1^2) + \\gamma (Q_2^2) \\rightarrow V_1 + V_2$ cross-sections for $V_i = \\rho$, $\\phi$, $J/\\psi$ and $\\Upsilon$ are computed and the energy and virtuality dependencies are studied in detail. Our results demonstrate that the experimental analysis of this process is feasible at the ILC and it can be useful to constrain the QCD dynamics at high energies.
CP Measurement in Quantum Teleportation of Neutral Mesons
Yu Shi; Yue-Liang Wu
2008-07-08
Quantum teleportation using neutral pseudoscalar mesons shows novel connections between particle physics and quantum information. The projection basis, which is crucial in the teleportation process, is determined by the conservation laws of particle physics, and is different from the Bell basis, as in the usual case. Here we show that one can verify the teleportation process by CP measurement. This method significantly simplifies the high energy quantum teleportation protocol. Especially, it is rigorous, and is independent of whether CP is violated in weak decays. This method can also be applied to general verification of Einstein-Podolsky-Rosen correlations in particle physics.
Search for CP Violation in D± Meson Decays to ??±
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Stari?, M.; Aihara, H.; Arinstein, K.; Asner, D. M.; Aushev, T.; Bakich, A. M.; Bay, A.; Bhardwaj, V.; Bhuyan, B.; Bozek, A.; et al
2012-02-13
We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D±?K?K??± and the Cabibbo-favored decays D±s?K?K??± in the K?K? mass region of the ? resonance. Using 955 fb?¹ of data collected with the Belle detector, we obtain AD?????CP=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.
Advanced Article Article Contents
O'Shea, Paul
-reduction) WILEY ENCYCLOPEDIA OF CHEMICAL BIOLOGY 2008, John Wiley & Sons, Inc. 1 #12;Membrane PotentialsAdvanced Article Article Contents · Biological Background · Physical Chemistry Background of Biological Roles and of Tech- nologies for Measurement Membrane Potentials in Living Systems, Tools
SCHOOLOFSCIENCE Table of Contents
Varela, Carlos
SCHOOLOFSCIENCE Table of Contents Degrees Offered and Associated Departments 324 Overview The Darrin Fresh Water Institute 401 New York Center for Studies on the Origins of Life 402 New York State
Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, Alberto; /Frascati; Antos, Jaroslav; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.
2009-05-01
The authors report the observation of the bottom, doubly-strange baryon {Omega}{sub b}{sup -} through the decay chain {Omega}{sub b}{sup -} {yields} J/{psi}{Omega}{sup -}, where J/{psi} {yields} {mu}{sup +} {mu}{sup -}, {Omega}{sup -} {yields} {Lambda}K{sup -}, and {Lambda} {yields} p {pi}{sup -}, using 4.2 fb{sup -1} of data from p{bar p} collisions at {radical}s = 1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 x 10{sup -8}, or 5.5 Gaussian standard deviations. The {Omega}{sub b}{sup -} mass is measured to be 6054.4 {+-} 6.8(stat.) {+-} 0.9(syst.) MeV/c{sup 2}. The lifetime of the {Omega}{sub b}{sup -} baryon is measured to be 1.13{sub -0.40}{sup +0.53}(stat.) {+-} 0.02(syst.) ps. In addition, for the {Xi}{sub b}{sup -} baryon they measure a mass of 5790.9 {+-} 2.6(stat.) {+-} 0.8(syst.) MeV/c{sup 2} and a lifetime of 1.56{sub -0.25}{sup +0.27}(stat.) {+-} 0.02(syst.) ps.
O(1/M^3) effects for heavy-light mesons in lattice NRQCD
Randy Lewis; R. M. Woloshyn
1998-05-30
The masses of spin-singlet and spin-triplet S-wave mesons containing a single heavy quark are computed in the quenched approximation. The light quark action and gauge field action are both classically-improved and tadpole-improved, and the couplings to the heavy quark are organized by the 1/M expansion of tadpole-improved NRQCD. At each of two lattice spacings, near 0.22fm and 0.26fm, meson masses are obtained for heavy quarks spanning the region between charmed and bottom mesons. Results up to O(1/M), O(1/M^2) and O(1/M^3) are displayed separately, so that the convergence of the heavy quark expansion can be discussed. Also, the effect of each term in the O(1/M^3) contribution is computed individually. For bottom mesons the 1/M-expansion appears to be satisfactory, but the situation for charmed mesons is less clear.
SuStainability table of contentS
Karonis, Nicholas T.
SuStainability table of contentS executive Summary-Related Sustainability Options ........................................... 41 Information Technology Infrastucture #12;sustainability 2 Private Giving
B-1400 8/11 of Your Food Content The Sodium #12;Contents Page Introduction.......................................................................................3 Sodium content of foods Beverages and fruit juices activity, and encourages Americans to consume more healthy foods like vegetables, fruits, seafood, whole
Search for CP violation in charged D meson decays
Yumiceva, Francisco Xavier; /South Carolina U.
2005-05-04
At the present time, Charge-Parity asymmetry or CP Violation is one of the most studied topics in high energy physics. Precise measurements of CP parameters can test sensitive sectors of the Standard Model (SM). These measurements could also give us clues about physics beyond the SM. Furthermore, since CP Violation is one of the necessary conditions for generating a matter-antimatter asymmetric Universe according to the baryogenesis model of Sakharov, a better understanding of these processes will improve our knowledge about the origin of the Universe. CP Violation in single Cabibbo-Suppressed charged D meson decays is predicted by the SM to have asymmetries of the order of {Omicron}(10{sup -3}), results bigger than this will be strong evidence of physics beyond the SM. We report results of the search for CP violation in D{sup +} {yields} K{sup -}K{sup +}{pi}{sup +} meson decays. The selection criteria were optimized using a control sample from data with a luminosity of 9.8 fb{sup -1}.
Energy loss, equilibration, and thermodynamics of a baryon rich strongly coupled quark-gluon plasma
Rougemont, Romulo; Finazzo, Stefano; Noronha, Jorge
2015-01-01
Lattice data for the QCD equation of state and the baryon susceptibility near the crossover phase transition (at zero baryon density) are used to determine the input parameters of a 5-dimensional Einstein-Maxwell-Dilaton holographic model that provides a consistent holographic framework to study both equilibrium and out-of-equilibrium properties of a hot and {\\it baryon rich} strongly coupled quark-gluon plasma (QGP). We compare our holographic equation of state computed at nonzero baryon chemical potential, $\\mu_B$, with recent lattice calculations and find quantitative agreement for the pressure and the speed of sound for $\\mu_B \\leq 400$ MeV. This holographic model is used to obtain holographic predictions for the temperature and $\\mu_B$ dependence of the drag force and the Langevin diffusion coefficients associated with heavy quark jet propagation as well as the jet quenching parameter $\\hat{q}$ and the shooting string energy loss of light quarks in the dense plasma. We find that the energy loss of heavy ...
Modified Baryonic Dynamics: two-component cosmological simulations with light sterile neutrinos
Angus, G.W.; Gentile, G.; Diaferio, A.; Famaey, B.; Heyden, K.J. van der E-mail: diaferio@ph.unito.it E-mail: gianfranco.gentile@ugent.be
2014-10-01
In this article we continue to test cosmological models centred on Modified Newtonian Dynamics (MOND) with light sterile neutrinos, which could in principle be a way to solve the fine-tuning problems of the standard model on galaxy scales while preserving successful predictions on larger scales. Due to previous failures of the simple MOND cosmological model, here we test a speculative model where the modified gravitational field is produced only by the baryons and the sterile neutrinos produce a purely Newtonian field (hence Modified Baryonic Dynamics). We use two-component cosmological simulations to separate the baryonic N-body particles from the sterile neutrino ones. The premise is to attenuate the over-production of massive galaxy cluster halos which were prevalent in the original MOND plus light sterile neutrinos scenario. Theoretical issues with such a formulation notwithstanding, the Modified Baryonic Dynamics model fails to produce the correct amplitude for the galaxy cluster mass function for any reasonable value of the primordial power spectrum normalisation.
Photo-production of Positive Parity Excited Baryons in the 1/Nc Expansion of QCD
Jose L. Goity Norberto N. Scoccola
2007-01-29
We analyze the photo-production helicity amplitudes for the positive parity excited baryons in the context of the $1/N_c$ expansion of QCD. The results show that sub-leading corrections in $1/N_c$ are important and that, while 1-body effective operators are dominant, there is some evidence for the need of 2-body effects.
The baryon vector current in the combined chiral and 1/Nc expansions
Flores-Mendieta, Ruben; Goity, Jose L
2014-12-01
The baryon vector current is computed at one-loop order in large-Nc baryon chiral perturbation theory, where Nc is the number of colors. Loop graphs with octet and decuplet intermediate states are systematically incorporated into the analysis and the effects of the decuplet-octet mass difference and SU(3) flavor symmetry breaking are accounted for. There are large-Nc cancellations between different one-loop graphs as a consequence of the large-Nc spin-flavor symmetry of QCD baryons. The results are compared against the available experimental data through several fits in order to extract information about the unknown parameters. The large-Nc baryon chiral perturbation theory predictions are in very good agreement both with the expectations from the 1/Nc expansion and with the experimental data. The effect of SU(3) flavor symmetry breaking for the |Delta S|=1 vector current form factors f1(0) results in a reduction by a few percent with respect to the corresponding SU(3) symmetric values.
Hadron resonance gas and mean-field nuclear matter for baryon number fluctuations
Kenji Fukushima
2014-09-09
We give an estimate for the skewness and the kurtosis of the baryon number distribution in two representative models; i.e., models of a hadron resonance gas and relativistic mean-field nuclear matter. We emphasize formal similarity between these two descriptions. The hadron resonance gas leads to a deviation from the Skellam distribution if quantum statistical correlation is taken into account at high baryon density, but this effect is not strong enough to explain fluctuation data seen in the beam-energy scan at RHIC/STAR. In the calculation of mean-field nuclear matter the density correlation with the vector \\omega-field rather than the effective mass with the scalar \\sigma-field renders the kurtosis suppressed at higher baryon density so as to account for the experimentally observed behavior of the kurtosis. We finally discuss the difference between the baryon number and the proton number fluctuations from correlation effects in isospin space. Our numerical results suggest that such effects are only minor even in the case of complete randomization of isospin.
RELATIVISTIC QUARK MODELS FOR BARYONS: THE EXTRAORDINARY WORLD OF ORDINARY MATTER.
Gent, Universiteit
as electromagnetic properties of strange baryons. 1. The trouble with medium-energy The words \\fundamental theory for a \\theory of everything" might even be called one of the principal quests of contemporary science and neutrons). It also brings order in three of the four fundamental forces through which the fermions interact
Hadron resonance gas and mean-field nuclear matter for baryon number fluctuations
Kenji Fukushima
2015-08-30
I give an estimate for the skewness and the kurtosis of the baryon number distribution in two representative models; i.e., models of a hadron resonance gas and relativistic mean-field nuclear matter. I emphasize formal similarity between these two descriptions. The hadron resonance gas leads to a deviation from the Skellam distribution if quantum statistical correlation is taken into account at high baryon density, but this effect is not strong enough to explain fluctuation data seen in the beam-energy scan at RHIC/STAR. In the calculation of mean-field nuclear matter the density correlation with the vector $\\omega$-field rather than the effective mass with the scalar $\\sigma$-field renders the kurtosis suppressed at higher baryon density so as to account for the experimentally observed behavior of the kurtosis. We finally discuss the difference between the baryon number and the proton number fluctuations from correlation effects in isospin space. The numerical results suggest that such effects are only minor even in the case of complete randomization of isospin.
CP Violation in Strange Baryon Decays: A Report from Fermilab Experiment 871
Fermilab Experiment E871
CP Violation in Strange Baryon Decays: A Report from Fermilab Experiment 871 C. James, a R. A, HyperCP , is a search for direct CP violation in \\Xi and \\Lambda hyperon decays. A nonÂzero valueÂ¯ \\Lambda , would be unambiguous evidence for direct CP violation. The first dataÂtaking run finished
Meson-Nucleon Physics: Past, Present and Future
B. M. K. Nefkens
2002-02-11
We will present some thoughts on the following topics: 1. Major highlights in the history of strong interactions such as isospin, the pion, SU(3), quarks, the color degree of freedom, QCD. 2. Topics of high current interest such as quark confinement, the origin of mass, the search for the gluon degrees of freedom, chiral symmetry, flavor symmetry, regularities in the properties of the light-baryon families (parity doublets, clusters) decay patterns, hadronization, chiral restoration, effective Lagrangians and their degrees of freedom. 3. The input parameters for QCD and for effective models. 4. Hadron physics as a necessary aspect of precision tests of the Standard Model and of the Search for New Physics.
Nucleon and Delta axial-vector couplings in 1/N{sub c}-Baryon Chiral Perturbation Theory
Goity, Jose Luis [JLAB; Calle Cordon, Alvaro [JLAB
2013-08-01
In this contribution, baryon axial-vector couplings are studied in the framework of the combined 1/N{sub c} and chiral expansions. This framework is implemented on the basis of the emergent spin-flavor symmetry in baryons at large N{sub c} and HBChPT, and linking both expansions ({xi}-expansion), where 1/N{sub c} is taken to be a quantity order p. The study is carried out including one-loop contributions, which corresponds to order xi to the third for baryon masses and order {xi} square for the axial couplings.
Content-Aware Image enhancement
Schettini, Raimondo
1 Content-Aware Image enhancement R. Schettini www.ivl.disco.unimib.it 8 Faculties, 61 Degree Recognition Content-based retrieval Quality Assessment Content-Aware Image Enhancement Presentation Outline Processing Content aware image enhancement We focus here on image based features. And show how to exploit
Content-Aware Image enhancement
Schettini, Raimondo
Content-Aware Image enhancement R. Schettini www.ivl.disco.unimib.it #12;8 Faculties, 61 Degree Recognition Content-based retrieval Quality Assessment #12;Content-Aware Image Enhancement Presentation Image Processing Content aware image enhancement We focus here on image based features. And show how
SPECTRA HOME CURRENT ISSUE TABLE OF CONTENTS TECHNOLOGY BUSINESS PRESSTIME BULLETIN ARTICLE Thomas Young's classic setup for the demonstration of interference features light from one source incident on two vertical slits because the phenomenon occurs only if the light from the slits has a well
Table of Contents Introduction
Nagy, Eric Sándor
include nitrogen oxides (NOx = NO + NO2 ), nitric acid (HNO3 ), nitrous oxide (N2 O, a greenhouse gas.TheHaber-BoschprocessalsosuppliesNH3 for industrial processes. Anthropogenic sources of nitrogen are twice as large as natural terDRAFT - 1 #12;2 - DRAFT Table of Contents Introduction What is Reactive Nitrogen and Why
Coherent Vector Meson Photoproduction with Nuclear Breakup in Relativistic Heavy Ion Collisions
Anthony J. Baltz; Spencer R. Klein; Joakim Nystrand
2002-05-10
Relativistic heavy ions are copious sources of virtual photons. The large photon flux gives rise to a substantial photonuclear interaction probability at impact parameters where no hadronic interactions can occur. Multiple photonuclear interactions in a single collision are possible. In this letter, we use mutual Coulomb excitation of both nuclei as a tag for moderate impact parameter collisions. We calculate the cross section for coherent vector meson production accompanied by mutual excitation, and show that the median impact parameter is much smaller than for untagged production. The vector meson rapidity and transverse momentum distribution are very different from untagged exclusive vector meson production.
Neutral meson production in pp and Pb-Pb collisions at the LHC measured with ALICE
D. Peresunko
2012-10-21
We present spectra of $\\pi^0$, $\\eta$ and $\\omega$ mesons in pp collisions and $\\pi^{0}$ mesons in Pb-Pb collisions measured with ALICE at LHC energies. The $\\pi^0$ and $\\eta$ mesons are reconstructed via their two-photon decays by two complementary methods, using the electromagnetic calorimeters and photon conversion technique; both measurements show perfect agreement. We measure the nuclear modification factor ($R_{AA}$) of $\\pi^0$ production in Pb-Pb collisions at different collision centralities and compare with lower energy results and theoretical predictions.
Impressions of the Meson Spectrum: Hybrids & Exotics, present and future
Pennington, M R
2015-01-01
It has long been expected that the spectrum of hadrons in QCD would be far richer and extensive than experiment has so far revealed. While there have been experimental hints of this richness for some time, it is really only in the last few years that dramatic progress has been seen in the exploration both experimentally and in calculations on the lattice. Precision studies enabled by new technology both with detectors and high performance computations are converging on an understanding of the spectrum in strong coupling QCD. These methodologies are laying the foundation for a decade of potential discovery that electro and photoproduction experiments at Jefferson Lab, which when combined with key results on $B$ and charmonium decays from both $e^+e^-$ and $pp$ colliders, should turn mere impressions of the light meson spectrum into a high definition picture.
Staggered fermions, zero modes, and flavor-singlet mesons
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Donald, Gordon C; Davies, Christine T.H.; Follana, Eduardo; Kronfeld, Andreas S.
2011-09-12
We examine the taste structure of eigenvectors of the staggered-fermion Dirac operator. We derive a set of conditions on the eigenvectors of modes with small eigenvalues (near-zero modes), such that staggered fermions reproduce the 't Hooft vertex in the continuum limit. We also show that, assuming these conditions, the correlators of flavor-singlet mesons are free of contributions singular in 1/m, where m is the quark mass. This conclusion holds also when a single flavor of sea quark is represented by the fourth root of the staggered-fermion determinant. We then test numerically, using the HISQ action, whether these conditions hold onmore »realistic lattice gauge fields. We find that the needed structure does indeed emerge.« less
Rare radiative decays of the $B_c$ meson
Ju, Wan-Li; Jiang, Yue; Yuan, Han; Wang, Guo-Li
2015-01-01
In this paper, we study the rare radiative processes $B_c\\to D_{(s)J} ^{(*)}\\gamma$ within the Standard Model, where $D_{(s)J}^{(*)}$ stands for the meson $D_{(s)}^*$, $D_{s1}(2460,2536)$ or $D_{s2}^*(2573)$. During the investigations, we consider the contributions from the penguin, annihilation, color-suppressed and color-favored cascade diagrams. Our results show that: 1) the penguin and annihilation contributions are dominant in the branching fractions; 2) for the processes $B_c\\to D_{(s)}^{*}\\gamma$ and $B_c\\to D_{s1}(2460)\\gamma$, the effects from the color-suppressed and color-favored cascade diagrams are un-ignorable.
Impressions of the Meson Spectrum: Hybrids & Exotics, present and future
M. R. Pennington
2015-09-08
It has long been expected that the spectrum of hadrons in QCD would be far richer and extensive than experiment has so far revealed. While there have been experimental hints of this richness for some time, it is really only in the last few years that dramatic progress has been seen in the exploration both experimentally and in calculations on the lattice. Precision studies enabled by new technology both with detectors and high performance computations are converging on an understanding of the spectrum in strong coupling QCD. These methodologies are laying the foundation for a decade of potential discovery that electro and photoproduction experiments at Jefferson Lab, which when combined with key results on $B$ and charmonium decays from both $e^+e^-$ and $pp$ colliders, should turn mere impressions of the light meson spectrum into a high definition picture.
New physics searches with B mesons at the ATLAS experiment
Nooney, Tamsin; The ATLAS collaboration
2015-01-01
The large amount of Heavy Flavour data collected by the ATLAS experiment is potentially sensitive to New Physics, which may be found in the mixing of B meson states, or through processes that are naturally suppressed in the Standard Model. We present the most recent results on the measurement of the decay of the $B_{s}$ into $J/\\psi$ $\\phi$ based on full data collected in LHC Run-1 and with updated flavour tagging improving the accuracy in the CP-violating phase $\\phi_{s}$. We also present the measurement of the decay time difference in the $B_{d}$ system. The most recent results on the search for the rare decay $B_{s}$ ($B^{0}$) $\\rightarrow$ $\\mu^{+}$ $\\mu^{-}$ are presented as well as results on the angular distribution parameters $A_{FB}$ and $F_{L}$ describing the decay $B_{d}$ $\\rightarrow$ $K^{*}\\mu^{+}\\mu^{-}$ $\\rightarrow$ $K^{+}\\pi^{-} \\mu^{+} \\mu^{-}$.
D-meson production in the GM-VFN scheme
B. A. Kniehl
2006-08-10
We study the inclusive hadrodroduction of D^0, D^+, D^{*+}, and D_s^+ mesons at next-to-leading order in the parton model of quantum chromodynamics endowed with universal non-perturbative fragmentation functions (FFs) fitted to e^+e^- annihilation data from CERN LEP1. Working in the general-mass variable-flavor-number scheme, we resum the large logarithms through the evolution of the FFs and, at the same time, retain the full dependence on the charm-quark mass without additional theoretical assumptions. In this way, the cross section distributions in transverse momentum recently measured by the CDF Collaboration in run II at the Fermilab Tevatron are described within errors.
T. M. Aliev; K. Azizi; M. Savci
2009-10-11
The electric quadrupole and magnetic octupole moments of the light decuplet baryons are calculated in the framework of the light cone QCD sum rules. The obtained non-vanishing values for the electric quadrupole and magnetic octupole moments of these baryons show nonspherical charge distribution. The sign of electric quadrupole moment is positive for $\\Omega^-$, $\\Xi^{*-}$, $\\Sigma^{*-}$ and negative for $\\Sigma^{*+}$, which correspond to the prolate and oblate charge distributions, respectively. A comparison of the obtained results with the predictions of non-covariant quark model which shows a good consistency between two approaches is also presented. Comparison of the obtained results on the multipole moments of the decuplet baryons containing strange quark with those of $\\Delta$ baryons shows a large SU(3) flavor symmetry breaking.
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1998-01-01
. Gollin, R. M. Hans, E. Johnson, I. Karliner, M. A. Marsh, M. Palmer, M. Selen, and J. J. Thaler University of Illinois, Champaign-Urbana, Illinois 61801 K. W. Edwards Carleton University, Ottawa, Ontario, Canada K1S 5B6 and the Institute of Particle... is defined in terms of the transition form factors F g*gR(Q2). In the case of pseudoscalar mesons there is only one form factor. At zero momentum transfer this form factor is expressed as uF g*gR~0 !u 2 5 1 ~ 4pa!2 64pG ~ R!gg! MR 3 , ~4! where a is the QED...
Measurements of B± Meson production at LHCb and characterisation of hybrid photon detectors
Young, Ross Donaldson
2012-08-08
LHCb is an experiment designed to make precision measurements of Charge- Parity violation in the B meson system. We report a measurement of the B± crosssection and production asymmetry, using B± ? J/u K± decays collected ...
Exotic Hybrid Meson Spectroscopy with the GlueX detector at Jlab
Lawrence, David W.
2014-03-01
The GlueX experiment is scheduled to begin taking data in 2015. The goal is to discover evidence for the existence of exotic hybrid mesons and to map out their spectrum in the light quark sector. Recent theoretical developments using Lattice QCD predict exotic hybrid states in a mass range accessible using the newly upgraded 12GeV electron accelerator at Jefferson Lab. 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. The experiment will use 9 GeV linearly polarized photons produced via coherent bremsstrahlung to produce the exotic hybrids. The decay products will be detected in the solenoid-based GlueX detector currently under construction at Jefferson Lab. The status of the GlueX experiment including detector parameters will be presented along with theoretical motivation for the experiment.
Interactions of $B_{c}$ Meson in Relativistic Heavy-Ion Collisions
Irfan, Shaheen; Masud, Bilal
2015-01-01
We calculate the absorbtion cross-sections of $B_{c}$ mesons by $\\pi$ and $\\rho$ mesons including anomalous processes using an effective hadronic Lagrangian. The enhancement of Bc production is expected due to QGP formation in heavy-ion experiments. However it is also expected that the production rate of Bc meson can be affected due to the interaction with comovers. These processes are relevant for experiments at RHIC. Thermal average cross-sections of $B_{c}$ are evaluated with form factor when a cut off parameter in it is 1 and 2 GeV. Using these thermal average cross-sections in the kinetic equation we investigate the time evolution of $B_{c}$ mesons due to dissociation in the hadronic matter formed at RHIC.
An AdS/QCD holographic wavefunction for the rho meson
J. R. Forshaw; R. Sandapen
2012-07-18
We use an AdS/QCD holographic wavefunction to generate predictions for the rate of diffractive {\\rho}-meson electroproduction that are in reasonable agreement with data collected at the HERA electron-proton collider.
? meson production in d+Au collisions at ?sNN = 200 GeV
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Adare, A.
2015-10-19
The PHENIX Collaboration has measured ? meson production in d+Au collisions at ?sNN=200 GeV using the dimuon and dielectron decay channels. The ? meson is measured in the forward (backward) d-going (Au-going) direction, 1.2 T) range from 1–7 GeV/c and at midrapidity |y|T range below 7 GeV/c. The ? meson invariant yields and nuclear-modification factors as a function of pT, rapidity, and centrality are reported. An enhancement of ? meson production is observed in the Au-going direction, while suppression is seen in the d-going direction,more »and no modification is observed at midrapidity relative to the yield in p+p collisions scaled by the number of binary collisions. As a result, similar behavior was previously observed for inclusive charged hadrons and open heavy flavor, indicating similar cold-nuclear-matter effects.« less
Qingfeng Li; Zhuxia Li
2010-10-13
A mean-field potential version of the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model is used to investigate the production of strange baryons, especially the $\\Lambda$s and $\\overline{\\Lambda}$s, from heavy ion collisions at SPS energies. It is found that, with the consideration of both formed and pre-formed hadron potentials in UrQMD, the transverse mass and longitudinal rapidity distributions of experimental data of both $\\Lambda$s and $\\overline{\\Lambda}$s can be quantitatively explained fairly well. Our investigation also shows that both the production mechanism and the rescattering process of hadrons play important roles in the final yield of strange baryons.
Spectrum and Bethe-Salpeter amplitudes of $?$ baryons from lattice QCD
Jian Liang; Wei Sun; Ying Chen; Wei-Feng Chiu; Ming Gong; Chuan Liu; Yu-Bin Liu; Zhaofeng Liu; Jian-Ping Ma; Jian-Bo Zhang
2015-11-13
The $\\Omega$ baryons with $J^P=3/2^\\pm, 1/2^\\pm$ are studied on the lattice in the quenched approximation. Their mass levels are ordered as $M_{3/2^+}
M. Albright; J. I. Kapusta
2015-08-11
We develop a flexible quasiparticle theory of transport coefficients of hot hadronic matter at finite baryon density. We begin with a hadronic quasiparticle model which includes a scalar and a vector mean field. Quasiparticle energies and the mean fields depend on temperature and baryon chemical potential. Starting with the quasiparticle dispersion relation, we derive the Boltzmann equation and use the Chapman-Enskog expansion to derive formulas for the shear and bulk viscosities and thermal conductivity. We obtain both relaxation time approximation formulas and more general integral equations. Throughout the work, we explicitly enforce the Landau-Lifshitz conditions of fit and ensure the theory is thermodynamically self-consistent. The derived formulas should be useful for predicting the transport coefficients of the hadronic phase of matter produced in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and at other accelerators.
Baryon chiral perturbation theory extended beyond the low-energy region
Epelbaum, E; Meißner, Ulf-G; Yao, De-Liang
2015-01-01
We consider an extension of the one-nucleon sector of baryon chiral perturbation theory beyond the low-energy region. The applicability of this approach for higher energies is restricted to small scattering angles, i.e. the kinematical region, where the quark structure of hadrons cannot be resolved. The main idea is to re-arrange the low-energy effective Lagrangian according to a new power counting and to exploit the freedom of the choice of the renormalization condition for loop diagrams. We generalize the extended on-mass-shell scheme for the one-nucleon sector of baryon chiral perturbation theory by choosing a sliding scale, that is we expand the physical amplitudes around kinematical points beyond the threshold. This requires the introduction of complex-valued renormalized coupling constants which can be either extracted from experimental data, or calculated using the renormalization group evolution of coupling constants fixed in threshold region.
Quark matter and meson properties in a Nonlocal SU(3) chiral quark model at finite temperature
Gomez Dumm, D.; Contrera, G. A.
2012-06-15
We study the finite temperature behavior of light scalar and pseudoscalar meson properties in the context of a three-flavor nonlocal chiral quark model. The model includes mixing with active strangeness degrees of freedom, and takes care of the effect of gauge interactions by coupling the quarks with a background color field. We analyze the chiral restoration and deconfinement transitions, as well as the temperature dependence of meson masses, mixing angles, and decay constants.
Dynamical Coupled-Channel Model of Meson Production Reactions in the Nucleon Resonance Region
T.-S. H. Lee; A. Matsuyama; T. Sato
2006-11-15
A dynamical coupled-channel model is presented for investigating the nucleon resonances (N*) in the meson production reactions induced by pions and photons. Our objective is to extract the N* parameters and to investigate the meson production reaction mechanisms for mapping out the quark-gluon substructure of N* from the data. The model is based on an energy-independent Hamiltonian which is derived from a set of Lagrangians by using a unitary transformation method.
Recent results on the nonmesonic weak decay of hypernuclei within a one-meson-exchange model
A. Parreno; A. Ramos; C. Bennhold
2001-09-06
We update our previous results for the nonmesonic decay of $^{12}_\\Lambda$C and $^5_\\Lambda$He. We pay special attention to the role played by Final State Intreractions on the decay observables. We follow a One-Meson-Exchange model which includes the exchange of the $\\pi, \\rho, K, K^*, \\eta$ and $\\omega$ mesons. We also present recent predictions for different observables concerning the decay of the doubly strange $^6_{\\Lambda \\Lambda}$He hypernucleus.
Production of D*+ (2010) mesons by high-energy neutrinos from the Tevatron
Asratian, A.E.; Aderholz, M.; Ammosov, V.V.; Barth, M.; Bingham, H.H.; Brucker, E.B.; Burnstein, R.A.; Chatterjee, T.K.; Clayton, E.C.; Ermolov, P.F.; Erofeeva, I.N.; Faulkner, P.J.W.; Gapienko, G.S.; Guy, J.; Hanlon, J.; Harigel, G.; Ivanilov, A.A.; Jain, V.; Jones, G.T.; Jones, M.D.; Kafka, T.; /UC, Berkeley /Birmingham U. /Brussels U., IIHE
1997-08-01
Charged vector D*{sup +}(2010) meson production is studied in a high energy neutrino bubble chamber experiment with mean neutrino energy of 141 GeV. The D*{sup +} are produced in (5.6 {+-} 1.8)% of the neutrino charged current interactions, indicating a steep increase of cross section with energy. The mean fractional hadronic energy of the D*{sup +} meson is 0.55 {+-} 0.06.
Note Added to ``Baryon Asymmetry of the Universe in the Standard Model"
G. R. Farrar; M. E. Shaposhnikov
1994-06-24
Recent papers by Gavela et al. and Huet et al. claim to have shown that incluion of higher order interactions between quasiparticles dramatically decreases the baryon asymmetry of the universe which can arise in the Minimal Standard Model. These papers employ an inconsistent calculational scheme which, for instance, violates unitarity. We argue that their method cannot be considered as reliable, and thus their conclusions cannot be considered as justified.
Baryon Production at LHC and Very High Energy Cosmic Ray Spectra
Olga I. Piskounova
2015-01-27
The spectra of baryons at LHC can explain the features of the proton spectra in cosmic rays (CR). It seems important to study all baryon data that are available from collider experiments in wide range of energies. Transverse momentum spectra of baryons from RHIC ($\\sqrt(s)$=62 and 200 GeV) and from LHC ($\\sqrt(s)$=0.9 and 7 TeV) have been considered. It is seen that the slope of distributions at low $p_T$'s is changing with energy. The QGSM fit of these spectra gives the average transverse momenta which behave as $s^{0.06}$ that is similar to the previously observed behavior of $\\Lambda^0$ hyperon spectra. The change in average transverse momenta that are slowly growing in VHE hadron interactions at CR detectors cannot cause the "knee" in measured cosmic ray proton spectra. In addition, the available data on heavy quark hadron production from LHC-b at $\\sqrt{s}$=7 TeV were also studied. The preliminary dependence of hadron average transverse momenta on their masses at LHC energy is presented. The possible source of cosmic ray antiparticle-to-particle ratios that are growing with energy was analyzed in the framework of QGSM, where the growing ratios are the result of local leading asymmetry between the production spectra of baryons and antibaryons in the kinematical region of proton target fragmentation. In the laboratory system of cosmic ray measurements this spectrum asymmetry will be seen as growing ratio of secondary antiparticle-to-particle spectra until the certain energy of secondaries. This conclusion makes the particle production at the sources of very high energy cosmic protons important, if the interactions with positive target matter would have place in proximity of these sources.
Vortical Motions of Baryonic Gas in the Cosmic Web: Growth History and Scaling Relation
Zhu, Weishan
2015-01-01
The vortical motions of the baryonic gas residing in large scale structures are investigated by cosmological hydrodynamic simulations. Proceeding in the formation of the cosmic web, the vortical motions of baryonic matter are pumped up by baroclinity in two stages, i.e., the formation of sheets, and filaments. The mean curl velocity are about $< 1$, 1-10, 10-150, 5-50 km/s in voids, sheets, filaments and knots at $z=0$, respectively. The scaling of the vortical velocity of gas can be well described by the She-Leveque hierarchical turbulence model in the range of $l<0.65(1.50) h^{-1}$ Mpc in simulation of box size 25(100) $h^{-1}$ Mpc. The fractal Hausdorff dimension of vortical motions, $d$, revealed by velocity structure functions, is $\\sim 2.1-2.3$($\\sim 1.8-2.1$). It is slightly larger than the fractal dimension of mass distribution in filaments, $\\textit{D}^f \\sim 1.9-2.2$, and smaller than the fractal dimension of sheets, $\\textit{D}^s \\sim 2.4-2.7$. The vortical kinetic energy of baryonic gas is m...
The thermal Sunyaev-Zel'dovich Signature of Baryons in the Local Universe
Carlos Hernandez-Monteagudo; Hy Trac; Raul Jimenez; Licia Verde
2006-06-07
Using cosmological hydrodynamical simulations, we investigate the prospects of the thermal Sunyaev-Zel'dovich (tSZ) effect to detect the missing baryons in the local universe. We find that at least 80% of the tSZ luminosity is generated in collapsed structures, and that $\\sim$ 70% of the remaining diffuse tSZ luminosity (i.e., $\\sim 15$% of the total) comes from overdense regions with $\\delta_{gas}>$10, such as filaments and superclusters. The gas present in slightly overdense and underdense regions with $\\delta_{gas} < 10$, despite making up 50% of the total baryon budget, leaves very little tSZ signature: it gives rise to only $\\sim$ 5% of the total tSZ luminosity. Thus, future Cosmic Microwave Background (CMB) observations will be sensitive to, at best, one half of the missing baryons, improving the current observational status, but still leaving one half unobserved. Since most of the tSZ is generated in haloes, we find a tight correlation between gas pressure and galaxy number density. This allows us to predict the CMB Comptonization from existing galaxy surveys and to forecast the tSZ effect from the local structures probed by the Two Micron All Sky Survey (2MASS) galaxy catalog.
Baryons as Hyperspherical O(4) Partial Waves is this the Message from the Spectra?
Kirchbach, M
1999-01-01
It is argued that the baryon excitations group to four-dimensional partial waves described by means of the three Rarita-Schwinger (RS) fields [(\\sigma -1 )/2 ,(\\sigma -1)/2]* [(1/2, 0)+(0,1/2)] with \\sigma =2,4 and 6, where all components happen to be occupied. In the O(4) decomposition of the \\pi N scattering amplitudes, the RS spin- and parity clusters appear as poles on the complex energy plane, socalled H"ohler poles. This phenomenon indicates that the symmetry of the \\pi N scattering amplitude is O(4) and thereby the space-time version of chiral symmetry, rather than O(3). Accordingly, the baryon spectrum generating algebra is su(2)_I*su(3)_c*o(1,3)_{ls} rather than su(6)_{sf} * su(3)_c * o(3)_l. The nucleon and \\Delta spectra below \\sim 2500 MeV are complete up to only 5 `missing' resonances. The three O(4) poles are distributed over two distinct Fock spaces of opposite vacuum parities thus defining the energy scale of the chiral phase transition for baryons. Within this new symmetry scenario, the covar...
Velocity Dependence of Baryon Screening in a Hot Strongly Coupled Plasma
Christiana Athanasiou; Hong Liu; Krishna Rajagopal
2008-05-12
The L-dependence of the static potential between Nc quarks arranged in a circle of radius L (a "baryon") immersed in the hot plasma of a gauge theory with Nc colors defines a screening length Ls. We use the AdS/CFT correspondence to compute this screening length for the case of heavy quarks in the plasma of strongly coupled N=4 super Yang-Mills theory moving with velocity v relative to the baryon. We find that in the v -> 1 limit, Ls \\propto (1-v^2)^{1/4}/T, and find that corrections to this velocity dependence are small at lower velocities. This result provides evidence for the robustness of the analogous behavior of the screening length defined by the static quark-antiquark pair, which has been computed previously and in QCD is relevant to quarkonium physics in heavy ion collisions. Our results also show that as long as the hot wind is not blowing precisely perpendicular to the plane of the baryon configuration that we analyze, the Nc different quarks are not all affected by the wind velocity to the same degree, with those quarks lying perpendicular to the wind direction screened most effectively.
The History of the Baryon Budget: Cosmic Logistics in a Hierarchical Universe
Yann Rasera; Romain Teyssier
2005-05-23
Using a series of high-resolution N-body hydrodynamical numerical simulations, we investigate several scenarios for the evolution of the baryon budget in galactic halos. We derive individual halo star formation history (SFH), as well as the global star formation rate in the universe. We develop a simple analytical model that allows us to compute surprisingly accurate predictions, when compared to our simulations, but also to other simulations presented in Springel & Hernquist (2003). The model depends on two main parameters: the star formation time scale t* and the wind efficiency eta_w. We also compute, for halos of a given mass, the baryon fraction in each of the following phases: cold disc gas, hot halo gas and stars. Here again, our analytical model predictions are in good agreement with simulation results, if one correctly takes into account finite resolution effect. We compare predictions of our analytical model to several observational constraints, and conclude that a very narrow range of the model parameters is allowed. The important role played by galactic winds is outlined, as well as a possible `superwind' scenario in groups and clusters. The `anti-hierarchical' behavior of observed SFH is well reproduced by our best model with t*=3Gyr and eta_w=1.5. We obtain in this case a present-day cosmic baryon budget of Omega*= 0.004, Omega_cold=0.0004, Omega_hot=0.01 and Omega_back=0.02 (diffuse background).
A Content Propagation Metric for Efficient Content Distribution
Keinan, Alon
A Content Propagation Metric for Efficient Content Distribution Ryan S. Peterson Cornell University@cs.cornell.edu ABSTRACT Efficient content distribution in large networks comprising data- centers, end hosts, and distributed in-network caches is a diffi- cult problem. Existing systems rely on mechanisms and metrics
Web Content Filtering 1 User Guidelines Web content filter guidelines
Swain, Peter
Web Content Filtering 1 User Guidelines Web content filter guidelines Introduction The basic criterion for blocking a Web page Categories of material which will be blocked Requesting the unblocking of Aberdeen applies a Web Content Filtering service to all web pages accessed from the undergraduate network
Perceptual Experience and Its Contents
Toribio, Josefa
2002-01-01
The contents of perceptual experience, it has been argued, often include a characteristic “non-conceptual” component (Evans, 1982). Rejecting such views, McDowell (1994) claims that such contents are conceptual in ...
Vector Meson Spectral Functions in a Coarse-Graining Approach
Stephan Endres; Hendrik van Hees; Janus Weil; Marcus Bleicher
2015-03-26
Dilepton production in heavy-ion collisions at top SPS energy is investigated within a coarse-graining approach that combines an underlying microscopic evolution of the nuclear reaction with the application of medium-modified spectral functions. Extracting local energy and baryon density for a grid of small space-time cells and going to each cell's rest frame enables to determine local temperature and chemical potential by application of an equation of state. This allows for the calculation of thermal dilepton emission. We apply and compare two different spectral functions for the $\\rho$: A hadronic many-body calculation and an approach that uses empirical scattering amplitudes. Quantitatively good agreement of the model calculations with the data from the NA60 collaboration is achieved for both spectral functions, but in detail the hadronic many-body approach leads to a better description, especially of the broadening around the pole mass of the $\\rho$ and for the low-mass excess. We further show that the presence of a pion chemical potential significantly influences the dilepton yield.
Personalized professional content recommendation
Xu, Songhua
2015-10-27
A personalized content recommendation system includes a client interface configured to automatically monitor a user's information data stream transmitted on the Internet. A hybrid contextual behavioral and collaborative personal interest inference engine resident to a non-transient media generates automatic predictions about the interests of individual users of the system. A database server retains the user's personal interest profile based on a plurality of monitored information. The system also includes a server programmed to filter items in an incoming information stream with the personal interest profile and is further programmed to identify only those items of the incoming information stream that substantially match the personal interest profile.
Personalized professional content recommendation
Xu, Songhua
2015-11-05
A personalized content recommendation system includes a client interface configured to automatically monitor a user's information data stream transmitted on the Internet. A hybrid contextual behavioral and collaborative personal interest inference engine resident to a non-transient media generates automatic predictions about the interests of individual users of the system. A database server retains the user's personal interest profile based on a plurality of monitored information. The system also includes a server programmed to filter items in an incoming information stream with the personal interest profile and is further programmed to identify only those items of the incoming information stream that substantially match the personal interest profile.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on77 PAGEMissionStressMoveMuncriefB NESEA Newsletter Content
Mixing and CP Violation in Charm Meson Decays
Meadows, B; /Cincinnati U.
2010-08-26
Mixing and CP violation (CPV ) in the neutral D system were first discussed over thirty years ago but mixing was observed for the first time only very recently. Since then, these observations have been confirmed in other experiments and in other D{sup 0} decay modes. Unlike the K, B and B{sub s} systems, for which mixing was observed years earlier, the short distance ({Delta}C = 2) amplitude contributing to mixing in the D system arises from box diagrams with down- rather than up-type quarks in the loops. The d and s components are GIM-suppressed, and the b component is suppressed by the small V{sub ub} CKM coupling. In the standard model (SM), therefore, long range, non-perturbative effects, a coherent sum over intermediate states accessible to both D{sup 0} and {bar D}{sup 0}, are the main contribution to mixing. These are hard to compute reliably, however. The phenomenon of mixing in neutral meson systems has now been observed in all flavours, but only in the past year in the D{sup 0} system. The standard model anticipated that, for the charm sector, the mixing rate would be small, and also that CP violation, either in mixing or in direct decay, would be below the present levels of observability. It is hoped that further study of these phenomena might reveal signs of new physics. A review of recently available, experimental results is given.
Nuclear mass form factors from coherent photoproduction of $?^0$ mesons
B. Krusche
2005-09-01
Data for coherent photoproduction of $\\pi^0$ mesons from nuclei ($^{12}$C, $^{40}$Ca, $^{93}$Nb, $^{nat}$Pb), recently measured with the TAPS detector at the Mainz MAMI accelerator, have been analyzed in view of the mass form factors of the nuclei. The form factors have been extracted in plane wave approximation of the $A(\\gamma ,\\pi^0)A$ reaction and corrected for final state interaction effects with the help of distorted wave impulse approximations. Nuclear mass rms-radii have been calculated from the slope of the form factors for $q^2\\to 0$. Furthermore, the Helm model (hard sphere form factor folded with Gaussian) was used to extract diffraction radii from the zeroes of the form factor and skin thicknesses from the position and height of its first maximum. The diffraction radii from the Helm model agree with the corresponding charge radii obtained from electron scattering experiments within their uncertainties of a few per cent. The rms-radii from the slope of the form factors are systematically lower by up to 5% for PWIA and up to 10% for DWIA. Also the skin thicknesses extracted from the Helm model are systematically smaller than their charge counter parts.
Experimental study of $?$ meson photoproduction reaction at MAMI
V. L. Kashevarov; the A2 Collaboration at MAMI
2015-06-08
New data for the differential cross sections, polarization observables $T$, $F$, and $E$ in the reaction of $\\eta$ photoproduction on proton from the threshold up to a center-of-mass energy of W=1.9 GeV are presented. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. The polarization measurements were made using a frozen-spin butanol target and circularly polarized photon beam. The results are compared to existing experimental data and different PWA predictions. The data solve a long-standing problem related the angular dependence of older $T$ data close to threshold. The unexpected relative phase motion between $s$- and $d$-wave amplitudes required by the old data is not confirmed. At higher energies, all model predictions fail to reproduce the new polarization data indicating a significant impact on our understanding of the underlying dynamics of $\\eta$ meson photoproduction. Furthermore, we present a fit of the new data and existing data from GRAAL for $\\Sigma$ asymmetry based on an expansion in terms of associated Legendre polynomials. A Legendre decomposition shows the sensitivity to small partial-wave contributions. The sensitivity of the Legendre coefficients to the nucleon resonance parameters is shown using the $\\eta$MAID isobar model.
Yu. G. Ignatyev; K. Alsmadi
2010-12-27
The complete model of production of baryons in expanding primordial symmetrical hot Universe is constructed in terms of general relativistic kinetic theory
Lei Weihua; Zhang Bing; Liang Enwei E-mail: zhang@physics.unlv.edu
2013-03-10
A hyperaccreting stellar-mass black hole has been long speculated as the best candidate for the central engine of gamma-ray bursts (GRBs). Recent rich observations of GRBs by space missions such as Swift and Fermi pose new constraints on GRB central engine models. In this paper, we study the baryon-loading processes of a GRB jet launched from a black hole central engine. We consider a relativistic jet powered by {nu} {nu}-bar -annihilation or by the Blandford-Znajek (BZ) mechanism. We consider baryon loading from a neutrino-driven wind launched from a neutrino-cooling-dominated accretion flow. For a magnetically dominated BZ jet, we consider neutron drifting from the magnetic wall surrounding the jet and subsequent positron capture and proton-neutron inelastic collisions. The minimum baryon loads in both types of jet are calculated. We find that in both cases a more luminous jet tends to be more baryon poor. A neutrino-driven ''fireball'' is typically ''dirtier'' than a magnetically dominated jet, while a magnetically dominated jet can be much cleaner. Both models have the right scaling to interpret the empirical {Gamma}-L{sub iso} relation discovered recently. Since some neutrino-driven jets have too much baryon loading as compared with the data, we suggest that at least a good fraction of GRBs should have a magnetically dominated central engine.
Excited meson radiative transitions from lattice QCD using variationally optimized operators
Christian J. Shultz; Jozef J. Dudek; Robert G. Edwards
2015-01-29
We explore the use of optimized operators, designed to interpolate only a single meson eigenstate, in three-point correlation functions with a vector-current insertion. These operators are constructed as linear combinations in a large basis of meson interpolating fields using a variational analysis of matrices of two-point correlation functions. After performing such a determination at both zero and non-zero momentum, we compute three-point functions and are able to study radiative transition matrix elements featuring excited state mesons. The required two- and three-point correlation functions are efficiently computed using the distillation framework in which there is a factorization between quark propagation and operator construction, allowing for a large number of meson operators of definite momentum to be considered. We illustrate the method with a calculation using anisotopic lattices having three flavors of dynamical quark all tuned to the physical strange quark mass, considering form-factors and transitions of pseudoscalar and vector meson excitations. The dependence on photon virtuality for a number of form-factors and transitions is extracted and some discussion of excited-state phenomenology is presented.
New insights into the $D^{*}_{s0}(2317)$ and other charm scalar mesons
Guo, Zhi-Hui; Yao, De-Liang
2015-01-01
Through the scattering of light-pseudoscalar mesons ($\\pi,K,\\eta,\\eta'$) off charmed mesons ($D, D_s$), we study the $D^{*}_{s0}(2317)$ state and other relevant charm scalar mesons in a unitarized chiral effective field theory approach. We investigate the charm scalar meson poles with different strangeness ($S$) and isospin ($I$) quantum numbers as well as their corresponding residues, which provide the coupling strengths of the charm scalar mesons. Both the light-quark mass and $N_C$ dependences of the pole positions of the $D^{*}_{s0}(2317)$ and the poles with $(S,I)=(0,1/2)$ are analyzed in detail in this work. Interestingly we observe quite similar pion mass trajectories for the resonance pole at around 2.1 GeV with $(S,I)=(0,1/2)$ to those of the $f_0(500)$ given in the literature. When increasing the values of $N_C$ we find that a bound state and a virtual state in the $(S,I)=(1,0)$ channel asymmetrically approach the $D K$ threshold for $N_C6$, the bound and virtual states move into the complex plane o...
Potential description of charmonium and charmed-strange mesons from lattice QCD
Taichi Kawanai; Shoichi Sasaki
2015-08-10
We present spin-independent and spin-spin interquark potentials for the charmonium and charmed-strange mesons, which are calculated in 2+1 flavor lattice QCD simulations using the PACS-CS gauge configurations generated at the lightest pion mass ($M_\\pi \\approx 156(7)$~MeV) with a lattice cutoff of $a^{-1}\\approx 2.2$ GeV and a spatial volume of $(3~{\\rm fm})^3$. For the charm quark, we use a relativistic heavy quark (RHQ) action with fine tuned RHQ parameters, which closely reproduce both the experimental spin-averaged mass and hyper-fine splitting of the $1S$ charmonium. The interquark potential and the quark kinetic mass, both of which are key ingredients within the potential description of heavy-heavy and heavy-light mesons, are determined from the equal-time Bethe-Salpeter (BS) amplitude. The charmonium potentials are obtained from the BS wave function of $1S$ charmonia ($\\eta_c$ and $J/\\psi$ mesons), while the charmed-strange potential are calculated from the $D_s$ and $D_s^{\\ast}$ heavy-light mesons. We then use resulting potentials and quark masses as purely theoretical inputs so as to solve the nonrelativistic Schr\\"odinger equation for calculating accessible energy levels of charmonium and charmed-strange mesons without unknown parameters. The resultant spectra below the $D\\bar{D}$ and $DK$ thresholds excellently agree with well-established experimental data.
Aspects of excited baryon phenomenology in the 1/N{sub c} expansion of QCD
Gonzalez de Urreta, E. J.; Scoccola, Norberto N.
2010-11-12
We report on the application of the 1/N{sub c} expansion of QCD to the description of the properties of non-strange excited baryons belonging to the [70, 1{sup -}]-plet. In particular, we present the results of an improved determination of the corresponding mixing angles obtained by performing a simultaneous fit of masses and strong decay widths. We find {theta}{sub 1} 0.47{+-}0.06 and {theta}{sub 3} = 2.74{+-}0.07. These values are within the range of those determined in previous non-global analyses but have smaller uncertainties.
Baryon Number and Electric Charge Fluctuations in High Energy Nucleus-Nucleus Collisions
Konchakovski, V P; Bratkovskaya, E L; Stöcker, H
2006-01-01
Event-by-event fluctuations of the net baryon number and electric charge in nucleus-nucleus collisions are studied in Pb+Pb at 158 AGeV within the HSD transport model. We reveal an important role of the fluctuations in the number of target nucleon participants. They strongly influence all measured fluctuations even in the samples of events with rather rigid centrality trigger. This fact can be used to check different scenarios of nucleus-nucleus collisions by measuring the multiplicity fluctuations as a function of collision centrality in fixed kinematical regions of the projectile and target hemispheres.
First measurement of coherent $\\phi$-meson photoproduction on deuteron at low energies
Tsutomu Mibe; Haiyan Gao; Kenneth Hicks; Kevin Kramer; Stepan Stepanyan; David Tedeschi; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; G. Asryan; Gerard Audit; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Lukasz Blaszczyk; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; Natalya Dashyan; Rita De Masi; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Richard Dickson; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; Charles Hanretty; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; John Johnstone; Kyungseon Joo; Henry Juengst; Narbe Kalantarians; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Zebulun Krahn; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Viacheslav Kuznetsov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Ji Li; Kenneth Livingston; Haiyun Lu; Marion MacCormick; Claude Marchand; Nikolai Markov; Paul Mattione; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Viktor Mokeev; Kei Moriya; Steven Morrow; M. Moteabbed; E. Munevar; Gordon Mutchler; P. Nadel-Turonski; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; S. Anefalos Pereira; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; S. Pozdniakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Julian Salamanca; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Dmitri Sharov; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Daria Sokhan; A. Stavinsky; Samuel Stepanyan; B.E. Stokes; Paul Stoler; I.I. Strakovsky; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao
2007-11-01
The cross section and decay angular distributions for the coherent \\phi meson photoproduction on the deuteron have been measured for the first time up to a squared four-momentum transfer t =(p_{\\gamma}-p_{\\phi})^2 =-2 GeV^2/c^2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are compared with predictions from a re-scattering model. In a framework of vector meson dominance, the data are consistent with the total \\phi-N cross section \\sigma_{\\phi N} at about 10 mb. If vector meson dominance is violated, a larger \\sigma_{\\phi N} is possible by introducing larger t-slope for the \\phi N \\to \\phi N process than that for the \\gamma N \\to \\phi N process. The decay angular distributions of the \\phi are consistent with helicity conservation.
Nonleptonic Weak Decays of B to D_s and D mesons
C. E. Thomas
2006-03-23
Branching ratios and polarization amplitudes for B decaying to all allowed pseudoscalar, vector, axial-vector, scalar and tensor combinations of D_s and D mesons are calculated in the Isgur Scora Grinstein Wise (ISGW) quark model after assuming factorization. We find good agreement with other models in the literature and the limited experimental data and make predictions for as yet unseen decay modes. Lattice QCD results in this area are very limited. We make phenomenological observations on decays in to D_s(2317) and D_s(2460) and propose tests for determining the status and mixings of the axial mesons. We use the same approach to calculate branching ratios and polarization fraction for decays in to two D type mesons.
Nambu's Nobel Prize, the $?$ meson and the mass of visible matter
Martin Schumacher
2014-11-05
The electroweak Higgs boson has been discovered in ongoing experiments at the LHC, leading to a mass of this particle of 126 GeV. This Higgs boson mediates the generation of mass for elementary particles, including the mass of elementary (current) quarks. These current-quark masses leave 98% of the mass of the atom unexplained. This large fraction is mediated by strong interaction, where instead of the Higgs boson the $\\sigma$ meson is the mediating particle. Though already discovered in 1957 by Schwinger, the $\\sigma$ meson has been integrated out in many theories of hadron properties because it had not been observed and was doubted to exist. With the observation of the $\\sigma$ meson in recent experiments on Compton scattering by the nucleon at MAMI (Mainz) it has become timely to review the status of experimental and theoretical researches on this topic.
Multiple scattering effects on heavy meson production in p+A collisions at backward rapidity
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kang, Zhong-Bo; Vitev, Ivan; Wang, Enke; Xing, Hongxi; Zhang, Cheng
2015-01-01
We study the incoherent multiple scattering effects on heavy meson production in the backward rapidity region of p+A collisions within the generalized high-twist factorization formalism. We calculate explicitly the double scattering contributions to the heavy meson differential cross sections by taking into account both initial-state and final-state interactions, and find that these corrections are positive. We further evaluate the nuclear modification factor for muons that come form the semi-leptonic decays of heavy flavor mesons. Phenomenological applications in d+Au collisions at a center-of-mass energy View the MathML sources=200 GeV at RHIC and in p+Pb collisions at View the MathML sources=5.02 TeVmore »at the LHC are presented. We find that incoherent multiple scattering can describe rather well the observed nuclear enhancement in the intermediate pTpT region for such reactions.« less
On the efficiency of stochastic volume sources for the determination of light meson masses
E. Endress; A. Jüttner; H. Wittig
2011-11-25
We investigate the efficiency of single timeslice stochastic sources for the calculation of light meson masses on the lattice as one varies the quark mass. Simulations are carried out with Nf = 2 flavours of non-perturbatively O(a) improved Wilson fermions for pion masses in the range of 450 - 760 MeV. Results for pseudoscalar and vector meson two-point correlation functions computed using stochastic as well as point sources are presented and compared. At fixed computational cost the stochastic approach reduces the variance considerably in the pseudoscalar channel for all simulated quark masses. The vector channel is more affected by the intrinsic stochastic noise. In order to obtain stable estimates of the statistical errors and a more pronounced plateau for the effective vector meson mass, a relatively large number of stochastic sources must be used.
Radiative decays of pseudoscalar (P) and vector (V) mesons and process e^+e^- \\to PV
Bystritskiy, Yu M; Volkov, M K
2008-01-01
Radiative decays of pseudoscalar and vector mesons are calculated in frames of chiral Nambu-Jona-Lasinio (NJL) model. We use triangle quark loops of anomalous type. During the evaluation of this loop integrals we used two methods. In first one we neglect the dependence of external momenta. In that case we reproduce the Wess-Zumino-Witten terms of effective chiral meson lagrangian. In the second method we take into account the momenta dependence of loop integrals omitting their imaginary part. That lets us to take into account quark confinement. The application of both methods are in qualitative agreement with each other and with experimental data. Second method allows us to describe the electron-positron annihilation with production pseudoscalar and vector mesons in center of mass energy range from 1 to 5 GeV. The comparison with the recent experimental data are presented.
Measurement of the [bar over B][0 over s] Meson Lifetime in D[+ over s]?[superscript ?] Decays
Aaij, R.
We present a measurement of the ratio of the [bar over B][0 over s] meson lifetime, in the flavor-specific decay to D[+ over s]?[superscript ?], to that of the [bar over B][superscript 0] meson. The pp collision data used ...
ContentsContents2424Fourier 1. The Fourier transform
Vickers, James
ContentsContents2424Fourier transforms 1. The Fourier transform 2. Properties of the Fourier Transform 3. Some Special Fourier Transform Pairs Learning outcomes needs doing Time allocation You mathematical topics this time may vary considerably. 1 #12;The Fourier Transform 24.1 Introduction
Power Corrections and the Gaussian Form of the Meson Wave Function
R. Akhoury; A. Sinkovics; M. G. Sotiropoulos
1997-10-16
The wave function of a light pseudoscalar meson is considered and nonperturbative corrections as signaled by perturbation theory are calculated. Two schemes are used, the massive gluon and the running coupling scheme. Both indicate the presence of leading power corrections of ${\\cal O}(b^2)$, whose exponentiation leads to a Gaussian dependence of the wave function on the impact parameter $b$. The dependence of this correction on the light cone energy fractions of the quark and the antiquark is discussed and compared with other models for the meson.
The static-light meson spectrum from twisted mass lattice QCD
ETM Collaboration; Karl Jansen; Chris Michael; Andrea Shindler; Marc Wagner
2008-10-10
We compute the static-light meson spectrum with N_f = 2 flavours of sea quarks using Wilson twisted mass lattice QCD. We consider five different values for the light quark mass corresponding to 300 MeV < m_PS < 600 MeV and we present results for angular momentum j = 1/2, j = 3/2 and j = 5/2 and for parity P = + and P = -. We extrapolate our results to physical quark masses and make predictions regarding the spectrum of B and B_s mesons.
Leptonic B- and D-meson decay constants with 2+1 flavors of asqtad fermions
Andreas S. Kronfeld; Ethan T. Neil; James N. Simone; Ruth S. Van de Water; for the Fermilab Lattice Collaboration; for the MILC Collaboration
2015-01-08
We present the status of our updated D- and B-meson decay-constant analysis, based on the MILC $N_f = 2+1$ asqtad gauge ensembles. Heavy quarks are incorporated using the Wilson clover action with the Fermilab interpretation. This analysis includes ensembles at five lattice spacings from a $\\approx$ 0.045 to 0.15 fm, and light sea-quark masses down to 1/20th of the strange-quark mass. Projected error budgets for ratios of decay constants, in particular between bottom- and charm-meson decay constants, are presented.
Neutral meson production in pp and Pb-Pb collisions at LHC
Yuri Kharlov; ALICE Collaboration
2012-08-23
The ALICE detector at the LHC studies $\\pi^0$ and $\\eta$ meson production by two complementary methods, using electromagnetic calorimeters and the central tracking system for converted photons. Production spectra of $\\pi^0$ and $\\eta$ mesons were measured with ALICE in pp collisions at LHC energies at mid-rapidity in a wide transverse momentum range. The spectrum and the nuclear modification factor $R_{AA}$ of $\\pi^0$ measured in Pb-Pb collisions at different centralities, show a clear pattern of strong suppression in a hot QCD medium with respect to pp collisions.
D meson mass increase by restoration of chiral symmetry in nuclear matter
Suzuki, Kei; Oka, Makoto
2015-01-01
Spectral functions of the pseudoscalar $D$ meson in the nuclear medium are analyzed using QCD sum rules and the maximum entropy method. This approach enables us to extract the spectral functions without any phenomenological assumption, and thus to visualize in-medium modification of the spectral functions directly. It is found that the reduction of the chiral condensates of dimension 3 and 5 causes the masses of both $D^+$ and $D^-$ mesons to grow gradually at finite density. Additionally, we construct charge-conjugate-projected sum rules and find a $D^+$-$D^-$ mass splitting of about -15 MeV at nuclear saturation density.
Keller, Dustin M. [University of Virginia; Hicks, Kenneth H. [OHIO
2013-05-01
The transition magnetic moments for decuplet-to-octet baryon electromagnetic decays are calculated from the CLAS experimental results and are compared with calculations to first order in the 1/N{sub c} expansion of quantum chromodynamics (QCD) and new U-spin predictions. Using the U-spin predictions for the {Sigma} *{sup 0} --> {Sigma}{sup 0} {gamma} and {Sigma} *{sup +} ? {Sigma}{sup +} {gamma} decays, the SU(3)-forbidden transition {Sigma} *{sup -} ? {Sigma}{sup -} {gamma} is obtained. In addition, the doubly strange baryon radiative decay {Xi} *{sup 0} ? {Xi} {gamma} is predicted using U-spin.
K. Azizi
2009-02-16
Due to the very short life time of the $\\Delta$ baryons, a direct measurement on the electromagnetic moments of these systems is almost impossible in the experiment and can only be done indirectly. Although only for the magnetic dipole moments of $\\Delta^{++}$ and $\\Delta^{+}$ systems there are some experimental data, the theoretical, phenomenological and lattice calculations could play crucial role. In present work, the magnetic dipole ($\\mu_{\\Delta}$) , electric quadrupole ($Q_{\\Delta}$) and magnetic octupole ($O_{\\Delta}$) moments of these baryons are computed within the light cone QCD sum rules. The results are compared with the predictions of the other phenomenological approaches, lattice QCD and existing experimental data.
The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Overview and Early Data
Dawson, Kyle S; Percival, Will J; Alam, Shadab; Albareti, Franco D; Anderson, Scott F; Armengaud, Eric; Aubourg, Eric; Bailey, Stephen; Bautista, Julian E; Berlind, Andreas A; Bershady, Matthew A; Beutler, Florian; Bizyaev, Dmitry; Blanton, Michael R; Blomqvist, Michael; Bolton, Adam S; Bovy, Jo; Brandt, W N; Brinkmann, Jon; Brownstein, Joel R; Burtin, Etienne; Busca, N G; Cai, Zheng; Chuang, Chia-Hsun; Clerc, Nicolas; Comparat, Johan; Cope, Frances; Croft, Rupert A C; Cruz-Gonzalez, Irene; da Costa, Luiz N; Cousinou, Marie-Claude; Darling, Jeremy; de la Torre, Sylvain; Delubac, Timothee; Bourboux, Helion du Mas des; Dwelly, Tom; Ealet, Anne; Eisenstein, Daniel J; Eracleous, Michael; Escoffier, S; Fan, Xiaohui; Finoguenov, Alexis; Font-Ribera, Andreu; Frinchaboy, Peter; Gaulme, Patrick; Georgakakis, Antonis; Green, Paul; Guo, Hong; Guy, Julien; Ho, Shirley; Holder, Diana; Huehnerhoff, Joe; Hutchinson, Timothy; Jing, Yipeng; Jullo, Eric; Kamble, Vikrant; Kinemuchi, Karen; Kirkby, David; Kitaura, Francisco-Shu; Klaene, Mark A; Laher, Russ R; Lang, Dustin; Laurent, Pierre; Goff, Jean-Marc Le; Li, Cheng; Liang, Yu; Lima, Marcos; Lin, Qiufan; Lin, Weipeng; Lin, Yen-Ting; Long, Daniel C; Lundgren, Britt; MacDonald, Nicholas; Maia, Marcio Antonio Geimba; Malanushenko, Elena; Malanushenko, Viktor; Mariappan, Vivek; McBride, Cameron K; McGreer, Ian D; Menard, Brice; Merloni, Andrea; Meza, Andres; Montero-Dorta, Antonio D; Muna, Demitri; Myers, Adam D; Nandra, Kirpal; Naugle, Tracy; Newman, Jeffrey A; Noterdaeme, Pasquier; Nugent, Peter; Ogando, Ricardo; Olmstead, Matthew D; Oravetz, Audrey; Oravetz, Daniel J; Padmanabhan, Nikhil; Palanque-Delabrouille, Nathalie; Pan, Kaike; Parejko, John K; Paris, Isabelle; Peacock, John A; Petitjean, Patrick; Pieri, Matthew M; Pisani, Alice; Prada, Francisco; Prakash, Abhishek; Raichoor, Anand; Reid, Beth; Rich, James; Ridl, Jethro; Rodriguez-Torres, Sergio; Rosell, Aurelio Carnero; Ross, Ashley J; Rossi, Graziano; Ruan, John; Salvato, Mara; Sayres, Conor; Schneider, Donald P; Schlegel, David J; Seljak, Uros; Seo, Hee-Jong; Sesar, Branimir; Shandera, Sarah; Shu, Yiping; Slosar, Anze; Sobreira, Flavia; Strauss, Michael A; Streblyanska, Alina; Suzuki, Nao; Tao, Charling; Tinker, Jeremy L; Tojeiro, Rita; Vargas-Magana, Mariana; Wang, Yuting; Weaver, Benjamin A; Weinberg, David H; White, Martin; Wood-Vasey, W M; Yeche, Christophe; Zhai, Zhongxu; Zhao, Cheng; Zhao, Gong-bo; Zheng, Zheng; Zhu, Guangtun Ben; Zou, Hu
2015-01-01
The Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. Observations will be simultaneous with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. eBOSS will use four different tracers to measure the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z=0.72, we project that eBOSS will yield measurements of $d_A(z)$ to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z>0.6 sample of BOSS galaxies. With ~195,000 new emission line galaxy redshifts, we expect BAO measurements of $d_A(z)$ to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z= 0.87. A sample of more than 500,000 spectroscop...
Polymer Chains and Baryons in a Strongly Coupled Quark-Gluon Plasma
Jinfeng Liao; Edward V. Shuryak
2005-11-03
Recently there was a significant change of views on physical properties and underlying dynamics of Quark-Gluon Plasma at $T=170-350 MeV$, produced in heavy ion collisions at RHIC. Instead of being a gas of $q,g$ quasiparticles, a near-perfect liquid is observed. Also, precisely in this temperature interval, the interaction deduced from lattice studies is strong enough to support multiple binary bound states. This work is the first variational study of {\\em multibody} bound states. We will consider: (i) ``polymer chains'' of the type $\\bar q g g ..g q$; (ii) baryons $(qqq)$; (iii) closed (3-)chains of gluons $(ggg)$. We found that chains (i) form in exactly the same $T$ range as binary states, with the same binding {\\em per bond}. The binding and $T$-range for diquarks, baryons and closed 3-chains are also established. We point out that the presence of chains, or possibly even a chain network, may drastically change the transport properties of matter, such as charm diffusion or jet energy loss. We further suggest that it seems to exist only for $T=(1-1.5)T_c$ and thus there may be a ``latent period'' for charm/jet quenching in RHIC collisions, while matter cools down to such $T$.
Quasar-Lyman ? forest cross-correlation from BOSS DR11: Baryon Acoustic Oscillations
Font-Ribera, Andreu; Kirkby, David; Blomqvist, Michael; Busca, Nicolas; Aubourg, Éric; Bautista, Julian; Ross, Nicholas P.; Bailey, Stephen; Beutler, Florian; Carithers, Bill; Slosar, Anže; Rich, James; Delubac, Timothée; Bhardwaj, Vaishali; Bizyaev, Dmitry; Brewington, Howard; Brinkmann, Jon; Brownstein, Joel R.; Dawson, Kyle S.; and others
2014-05-01
We measure the large-scale cross-correlation of quasars with the Ly? forest absorption, using over 164,000 quasars from Data Release 11 of the SDSS-III Baryon Oscillation Spectroscopic Survey. We extend the previous study of roughly 60,000 quasars from Data Release 9 to larger separations, allowing a measurement of the Baryonic Acoustic Oscillation (BAO) scale along the line of sight c/(H(z = 2.36)r{sub s}) = 9.0±0.3 and across the line of sight D{sub A}(z = 2.36)/r{sub s} = 10.8±0.4, consistent with CMB and other BAO data. Using the best fit value of the sound horizon from Planck data (r{sub s} = 147.49 Mpc), we can translate these results to a measurement of the Hubble parameter of H(z = 2.36) = 226±8 km s{sup ?1} Mpc{sup ?1} and of the angular diameter distance of D{sub A}(z = 2.36) = 1590±60 Mpc. The measured cross-correlation function and an update of the code to fit the BAO scale (baofit) are made publicly available.
Baryon Asymmetry and Dark Matter Through the Vector-Like Portal
Pavel Fileviez Perez; Mark B. Wise
2013-05-14
A possible connection between the cosmological baryon asymmetry, dark matter and vector-like fermions is investigated. In this scenario an asymmetry generated through baryogenesis or leptogenesis (in the vector-like matter sector) connects the baryon asymmetry to the dark matter density. We present explicit renormalizable models where this connection occurs. These models have asymmetric dark matter and a significant invisible Higgs decay width to dark matter particles is possible. We refer to this type of scenario as the vector-like portal. In some asymmetric dark matter models there are potential naturalness issues for the low energy effective theory. We address that issue in the models we consider by starting with a Lagrangian that is the most general renormalizable one consistent with the gauge (and discrete) symmetries and showing the low energy effective theory automatically has the required form as a consequence of the symmetries of the full theory. We show that the mass of the dark matter candidate is predicted in these scenarios.
Baryon states with hidden charm in the extended local hidden gauge approach
Uchino, T; Oset, E
2015-01-01
The s-wave interaction of $\\bar{D} \\Lambda_c, \\bar{D} \\Sigma_c, \\bar{D} \\Lambda_c, \\bar{D}{}^* \\Sigma_c$ and $\\bar{D}\\Sigma^*_c, \\bar{D}{}^*\\Sigma^*_c$, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of $\\bar{D}\\Sigma_c$ - $\\bar{D}{}^*\\Sigma_c$ with $J^P = 1/2^-$, and two of $\\bar{D}\\Sigma^*_c$ - $\\bar{D}{}^*\\Sigma^*_c$ with $J^P = 3/2^-$. Moreover, we find a $\\bar{D}{}^* \\Sigma_c$ resonance which couples to the $\\bar{D}\\Lambda_c$ channel and one spin degenerated ...
The static-light baryon spectrum from twisted mass lattice QCD
Marc Wagner; Christian Wiese
2011-04-26
We compute the static-light baryon spectrum by means of Wilson twisted mass lattice QCD using N_f = 2 flavors of sea quarks. As light u/d valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in the range 340 MeV < m_PS < 525 MeV, as well as partially quenched s quarks, which have a mass around the physical value. We consider all possible combinations of two light valence quarks, i.e. Lambda, Sigma, Xi and Omega baryons corresponding to isospin I = 0, 1/2, 1 and strangeness S = 0, -1, -2 as well as angular momentum of the light degrees of freedom j = 0, 1 and parity P = +, -. We extrapolate in the light u/d and in the heavy b quark mass to the physical point and compare with available experimental results. Besides experimentally known positive parity states we are also able to predict a number of negative parity states, which have neither been measured in experiments nor previously been computed by lattice methods.
Freeland, E.; Wilcots, E. E-mail: ewilcots@astro.wisc.edu
2011-09-10
Radio galaxies with bent jets are predominantly located in groups and clusters of galaxies. We use bent-double radio sources, under the assumption that their jets are bent by ram pressure, to probe intragroup medium (IGM) gas densities in galaxy groups. This method provides a direct measurement of the intergalactic gas density and allows us to probe intergalactic gas at large radii and in systems whose IGM is too cool to be detected by the current generation of X-ray telescopes. We find gas with densities of 10{sup -3} to 10{sup -4} cm{sup -3} at group radii from 15 to 700 kpc. A rough estimate of the total baryonic mass in intergalactic gas is consistent with the missing baryons being located in the IGM of galaxy groups. The neutral gas will be easily stripped from dwarf galaxies with total masses of 10{sup 6}-10{sup 7} M{sub sun} in the groups studied here. Indications are that intragroup gas densities in less-massive systems like the Local Group should be high enough to strip gas from dwarfs like Leo T and, in combination with tides, produce dwarf spheroidals.
Gross, Rudolf
1 #12;CONTENTS 2 Contents 1 Motivation 4 2 Circuit QED and Two-Resonator Circuit-QED 6 2.1 Coupled Fabrication Parameters 94 D E-beam Sample Holder 96 E Danksagungen 103 #12;1 MOTIVATION 4 1 Motivation
Observation of an Excited B[± over c] Meson State with the ATLAS Detector
Taylor, Frank E.
A search for excited states of the B[± over c] meson is performed using 4.9??fb[superscript ?1] of 7 TeV and 19.2??fb[superscript ?1] of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is ...
Contrera, G. A.; Dumm, D. Gomez; Scoccola, Norberto N.
2010-03-01
We study the finite temperature behavior of light scalar and pseudoscalar meson properties in the context of a three-flavor nonlocal chiral quark model. The model includes mixing with active strangeness degrees of freedom, and takes care of the effect of gauge interactions by coupling the quarks with the Polyakov loop. We analyze the chiral restoration and deconfinement transitions, as well as the temperature dependence of meson masses, mixing angles and decay constants. The critical temperature is found to be T{sub c{approx_equal}}202 MeV, in better agreement with lattice results than the value recently obtained in the local SU(3) PNJL model. It is seen that above T{sub c} pseudoscalar meson masses get increased, becoming degenerate with the masses of their chiral partners. The temperatures at which this matching occurs depend on the strange quark composition of the corresponding mesons. The topological susceptibility shows a sharp decrease after the chiral transition, signalling the vanishing of the U(1){sub A} anomaly for large temperatures.
Low Mass Vector Meson Measurements via Di-electrons at RHIC by the PHENIX Experiment
Deepali Sharma; for the PHENIX Collaboration
2009-01-21
The PHENIX experiment at RHIC has measured $\\omega$ and $\\phi$ mesons in $p+p$, $d+Au$ and $Au+Au$ collisions at \\sqn = 200 GeV via both hadronic and di-electron decay channels. The transverse momentum spectra as measured in different decay modes and at different centralities are shown and discussed here.
Decay constants of heavy-light vector mesons from QCD sum rules
Patrick Gelhausen; Alexander Khodjamirian; Alexei A. Pivovarov; Denis Rosenthal
2015-03-27
We revisit QCD sum rules for the decay constants of heavy-light mesons. In the sum rules for the vector mesons B^*_(s) and D^*_(s) we improve the accuracy of OPE, taking into account the O(alpha_s^2) terms in the perturbative part and calculating the O(alpha_s) corrections to the quark-condensate contribution. With this accuracy, we obtain the ratios of decay constants: f_B^*/f_B=1.02 +0.07 -0.03, f_D^*/f_D=1.20 +0.10 -0.07. The sum rule predictions for the decay constants of pseudoscalar mesons are updated with the results f_B=(207 +17 -9) MeV, f_B_s=(242 +17 -12) MeV, f_D=(201 +12 -13) MeV, f_D_s=(238 +13 -23) MeV. In order to assess the sensitivity of our calculation to the form of the sum rule, we consider alternative versions such as the power moments and Borel sum rules with different weights of the spectral density. We also investigated the heavy quark limit of the sum rules for vector and pseudoscalar mesons, estimating the violations of the heavy-quark spin and flavour symmetry.
Light-Cone Distribution Amplitudes for the Light $1^1P_1$ Mesons
Kwei-Chou Yang
2005-10-27
We present a study of light-cone distribution amplitudes of the light $1^1P_1$ mesons. The first few Gegenbauer moments of leading twist light-cone distribution amplitudes are calculated by using the QCD sum rule technique.
PHYSICAL REVIEW C 87, 064608 (2013) Nuclear meson transparency in a relativistic Glauber model
Gent, Universiteit
2013-01-01
PHYSICAL REVIEW C 87, 064608 (2013) Nuclear meson transparency in a relativistic Glauber model W traditional nuclear-physics calculations. The measurement of the onset and magnitude of the CT effect allows. Cosyn* and J. Ryckebusch Department of Physics and Astronomy, Ghent University, Proeftuinstraat 86, B
What can we Learn from a 2nd Phi-Meson Peak in Ultrarelativistic Nuclear Collisions
Ko, Che Ming; Seibert, D.
1994-01-01
the reactions phipi --> KK*, phiK --> phiK, phirho --> KK, and phiphi --> KK. The resulting phi meson width in hot hadronic matter is found to be less than about 10 MeV for temperatures below 200 MeV. If hadronic matter has a strong first-order phase transition...
Heavy Quark Kinetic Energy in B Mesons by a QCD Relativistic Potential Model
F. De Fazio
1996-11-04
The matrix element of the kinetic energy operator between B meson states is computed by means of a QCD relativistic potential model, with the result: $\\mu_\\pi^2=0.66 GeV^2$. A comparison with the outcome of other theoretical approaches and a discussion of the phenomenological implications of this result are carried out.
Mesons and Nucleons in Soft-Wall AdS/QCD
Peng Zhang
2010-10-13
We study further the soft-wall AdS/QCD model with a cubic potential for the bulk scalar. We analyze the spectra of pseudoscalar, scalar, vector and axial-vector mesons. We also study the spin-1/2 nucleon spectrum and the pion-nucleon coupling. All of them have a good agreement with the experimental data.
Diffractive vector meson production at HERA using holographic AdS/QCD wavefunctions
Jeff Forshaw; Ruben Sandapen
2013-05-16
We demonstrate another success of the AdS/QCD correspondence by showing that an AdS/QCD holographic light-front wavefunction for the $\\rho$ meson generates predictions for the cross-sections of diffractive $\\rho$ production that are in agreement with data collected at the HERA electron-proton collider.
Nuclear Physics A 611 ( 1996) 484-513 Mesonic and binding contributions to the EMC
Fernández de Córdoba, Pedro
NUCLEAR PHYSICS A Nuclear Physics A 611 ( 1996) 484-513 Mesonic and binding contributions November 1995; revised 30 July 1996 Abstract We revise the conventional nuclear effects of Fermi motion for an interacting Fermi sea and the local density approximation to translate results from nuclear matter to finite
Search for neutrinoless tau decays involving pi(0) or eta mesons
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Hancock, N.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan
1997-08-01
We have searched for lepton flavor violating decays of the tau lepton using final states with an electron Or a muon and one or two pi(0) or eta mesons but no neutrinos. The data used in the search were collected with the CLEO II detector...
Interpretation of Scalar and axial mesons in LHCb from an historical perspective
F. E. Close; A. Kirk
2015-03-24
LHCb measurements of $B_{d,s} \\to J/\\psi + X$ are shown to be consistent with historical data on scalar and axial mesons below 2 GeV. This is in contrast to some recent interpretations of these data. Further tests of our hypotheses in other $B_{u,d,s} \\to J/\\psi + X$ decay modes are suggested.
The Role of Mesons in the Electromagnetic Form Factors of the Nucleon
C. Crawford; T. Akdogan; R. Alarcon; W. Bertozzi; E. Booth; T. Botto; J. R. Calarco; B. Clasie; A. DeGrush; T. W. Donnelly; K. Dow; M. Farkhondeh; R. Fatemi; O. Filoti; W. Franklin; H. Gao; E. Geis; S. Gilad; D. Hasell; P. Karpius; M. Kohl; H. Kolster; T. Lee; E. Lomon; A. Maschinot; J. Matthews; K. McIlhany; N. Meitanis; R. Milner; J. Rapaport; R. Redwine; J. Seely; A. Shinozaki; A. Sindile; S. Sirca; E. Six; T. Smith; B. Tonguc; C. Tschalaer; E. Tsentalovich; W. Turchinetz; Y. Xiao; W. Xu; C. Zhang; Z. Zhou; V. Ziskin; T. Zwart
2010-08-01
The roles played by mesons in the electromagnetic form factors of the nucleon are explored using as a basis a model containing vector mesons with coupling to the continuum together with the asymptotic $Q^2$ behavior of perturbative QCD. Specifically, the vector dominance model (GKex) developed by Lomon is employed, as it is known to be very successful in representing the existing high-quality data published to date. An analysis is made of the experimental uncertainties present when the differences between the GKex model and the data are expanded in orthonormal basis functions. A main motivation for the present study is to provide insight into how the various ingredients in this model yield the measured behavior, including discussions of when dipole form factors are to be expected or not, of which mesons are the major contributors, for instance, at low-$Q^2$ or large distances, and of what effects are predicted from coupling to the continuum. Such insights are first discussed in momentum space, followed by an analysis of how different and potentially useful information emerges when both the experimental and theoretical electric form factors are Fourier transformed to coordinate space. While these Fourier transforms should not be interpreted as "charge distributions", nevertheless the roles played by the various mesons, especially which are dominant at large or small distance scales, can be explored via such experiment--theory comparisons.
Heavy-quark expansion for D and B mesons in nuclear matter
Thomas Buchheim; Thomas Hilger; Burkhard Kampfer
2014-10-01
The planned experiments at FAIR enable the study of medium modifications of $D$ and $B$ mesons in (dense) nuclear matter. Evaluating QCD sum rules as a theoretical prerequisite for such investigations encounters heavy-light four-quark condensates. We utilize an extended heavy-quark expansion to cope with the condensation of heavy quarks.
Lattice QCD study of the scalar mesons a0(1450) and sigma(600)
Nilmani Mathur; A. Alexandru; Y. Chen; S.J. Dong; T. Draper; I. Horvath; F.X. Lee; K.F. Liu; S. Tamhankar; J.B. Zhang
2007-12-01
We study the a{sub 0} and {sigma} mesons with the overlap fermion in the chiral regime with the pion mass as low as 182 MeV in the quenched approximation. After the {eta} N ghost states are separated, we find that the a{sub 0} mass with q{bar q} interpolation field to be almost independent of the quark mass in the region below the strange quark mass. The chirally extrapolated results are consistent with a{sub 0}(1450) being the u{bar d} meson and K{sub 0}*(1430) being the u {bar s} meson. We also calculate the scalar mesonium with a tetraquark interpolation field. In addition to the two pion scattering states, we found a state at {approx} 550 MeV. Through the study of volume dependence, we confirm that this state is a one-particle state, in contrast to the two-pion scattering states. This suggests that the observed state is a tetraquark mesonium which is quite possibly the {sigma}(600) meson.
Photoproduction of eta-mesons off nuclei for Eg < 2.2 GeV
T. Mertens; I. Jaegle; P. Muehlich; J. C. S. Bacelar; B. Bantes; O. Bartholomy; D. E. Bayadilov; R. Beck; Y. A. Beloglazov; R. Castelijns; V. Crede; H. Dutz; A. Ehmanns; D. Elsner; K. Essig; R. Ewald; I. Fabry; K. Fornet-Ponse; M. Fuchs; C. Funke; R. Gothe; R. Gregor; A. B. Gridnev; E. Gutz; S. Hoeffgen; P. Hoffmeister; I. Horn; J. Junkersfeld; H. Kalinowsky; S. Kammer; V. Kleber; Frank Klein; Friedrich Klein; E. Klempt; M. Konrad; M. Kotulla; B. Krusche; M. Lang; J. Langheinrich; H. Loehner; I. V. Lopatin; J. Lotz; S. Lugert; D. Menze; J. G. Messchendorp; V. Metag; C. Morales; U. Mosel; M. Nanova; D. V. Novinski; R. Novotny; M. Ostrick; L. M. Pant; H. van Pee; M. Pfeiffer; A. K. Radkov; A. Roy; S. Schadmand; C. Schmidt; H. Schmieden; B. Schoch; S. Shende; V. Sokhoyan; A. Suele; V. V. Sumachev; T. Szczepanek; U. Thoma; D. Trnka; R. Varma; D. Walther; C. Weinheimer; C. Wendel
2008-10-15
Photoproduction of $\\eta$ mesons off $^{12}$C, $^{40}$Ca, $^{93}$Nb, and $^{nat}$Pb nuclei has been measured with a tagged photon beam with energies between 0.6 and 2.2 GeV. The experiment was performed at the Bonn ELSA accelerator with the combined setup of the Crystal Barrel and TAPS calorimeters. It aimed at the in-medium properties of the S$_{11}$(1535) nucleon resonance and the study of the absorption properties of nuclear matter for $\\eta$ mesons. Careful consideration was given to contributions from $\\eta\\pi$ final states and secondary production mechanisms of $\\eta$-mesons e.g. from inelastic $\\pi N$ reactions of intermediate pions. The analysis of the mass number scaling shows that the nuclear absorption cross section $\\sigma_{N\\eta}$ for $\\eta$ mesons is constant over a wide range of the $\\eta$ momentum. The comparison of the excitation functions to data off the deuteron and to calculations in the framework of a BUU-model show no unexplained in-medium modifications of the S$_{11}$(1535).
Exploring free-form smearing for bottomonium and B meson spectroscopy
Mark Wurtz; Randy Lewis; R. M. Woloshyn
2015-10-19
Free-form smearing was designed as a way to implement source operators of any desired shape. A variation of the method is introduced that reduces the computational cost by reducing the number of link multiplications to its absolute minimum. Practical utility is demonstrated through calculations of bottomonium and B meson masses.
The rho meson decay constant using a tadpole-improved action
Randy Lewis; R. M. Woloshyn
1996-07-25
The rho meson decay constant and the associated renormalization factor are computed in the quenched approximation on coarse lattices using a tadpole-improved action which is corrected at the classical level to O(a^2). The improvement is displayed by comparing to Wilson action calculations.
An alternative approach to the $?$-meson-exchange in nucleon-nucleon interaction
Lingzhi Chen; Hourong Pang; Hongxia Huang; Jialun Ping; Fan Wang
2007-03-30
Through a quantitative comparative study of the properties of deuteron and nucleon-nucleon interaction with chiral quark model and quark delocalization color screening model. We show that the $\\sigma$-meson exchange used in the chiral quark model can be replaced by quark delocalization and color screening mechanism.
Hiroyuki Kamano
2011-08-23
We present an alternative interpretation for the dynamical origin of the P11 nucleon resonances, which results from the dynamical coupled-channels analysis at Excited Baryon Analysis Center of Jefferson Lab. The results indicate the crucial role of the multichannel reaction dynamics in determining the N^* spectrum.
Visual Analysis of Weblog Content
Gregory, Michelle L.; Payne, Deborah A.; McColgin, Dave; Cramer, Nick O.; Love, Douglas V.
2007-03-26
In recent years, one of the advances of the World Wide Web is social media and one of the fastest growing aspects of social media is the blogosphere. Blogs make content creation easy and are highly accessible through web pages and syndication. With their growing influence, a need has arisen to be able to monitor the opinions and insight revealed within their content. In this paper we describe a technical approach for analyzing the content of blog data using a visual analytic tool, IN-SPIRE, developed by Pacific Northwest National Laboratory. We highlight the capabilities of this tool that are particularly useful for information gathering from blog data.
A comment on chiral restoration at finite baryon density in hyperspherical unit cells
Hilmar Forkel
2012-04-12
Prompted by recent work of Adhikari, Cohen, Ayyagari and Strother "On chiral symmetry restoration at finite density in large-N_c QCD" (Phys. Rev. C 83, 065201 (2011)), we revisit the description of dense baryonic matter in terms of hyperspherical unit cells. We focus mainly on the interpretation of the unique energy, curvature and symmetry properties which enable such S^3 cells to describe full chiral restoration in Skyrme models and which markedly distinguish them from the flat and periodic unit cells of Skyrmion crystals. These key features clarify, in particular, why an S^3 cell interpretation as a crystal-cell model in which the specific cell geometry is without physical significance, as tentatively adopted by Adhikari et al., is insufficient. The ensuing criticism does therefore not apply to the usual interpretation of S^3 cells which we describe. We also suggest a few directions in which the latter interpretation may be developed further.
Model-Independent Dark Energy Equation of State from Baryon Acoustic Oscillations
Jarah Evslin
2015-10-20
We present a simple formula for the average dark energy equation of state at redshifts between those of two observations of baryon acoustic oscillations (BAO). The formula is independent of any parametrization or basis of the dark energy equation of state and essentially independent of the cosmological model. We use this formula to study the well-known tension between Lyman alpha forest BAO and other cosmological probes. Using only the line of sight Lyman alpha forest BAO and BOSS CMASS dataset, there is already more than 2 sigma tension with the standard LambdaCDM cosmological model which implies that either (i) The BOSS Lyman alpha forest measurement of the Hubble parameter was too low as a result of a statistical fluctuation or systematic error or else (ii) the dark energy equation of state falls steeply at high redshift.
Comment on the Walliser-Weigel approach to exotic baryons in chiral soliton models
Thomas D. Cohen
2005-11-16
This comment discusses a recent paper by Walliser and Weigel on the quantization of chiral soliton models in the context of exotic baryons. Claims made in that work are misleading due to unfortunate nomenclature. Moreover, attempts in that paper to go beyond the leading order calculations of the phase shifts are ad hoc and never justified. This comment also addresses a technical issue in that paper: the identification of the excitation energy of the pentaquark obtained via conventional rigid rotor quantization with a frequency obtained in the context of small amplitude fluctuations. The identification is erroneous: the small amplitude fluctuation result is based on a first-order perturbation computation of the frequency around a zero mode solution at a frequency far from zero and well away from the perturbative regime.
Observation of the Baryonic Flavor-Changing Neutral Current Decay ?b0 ? ?µ+µ-
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Aaltonen, T.
2011-11-08
The authors report the first observation of the baryonic flavor-changing neutral current decay ?b0 ? ?µ+µ- with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses a pp? collisions data sample corresponding to 6.8 fb-1 at ?s = 1.96 TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for ?b0 ? ?µ+µ- are measured. They find ?(?b0 ? ?µ+µ-) = [1.73 ± 0.42(stat) ± 0.55(syst)] x 10-6. They also report the first measurement of the differential branching ratio of Bs0??µ+µ- using 49 signal events. In addition,more »they report branching ratios for B+?K+µ+µ-, B0?K0µ+µ- and ?? K*(892)µ+µ- decays.« less
Spectral-Fluctuations Test of the Quark-Model Baryon Spectrum
Fernandez-Ramirez, C.; Relano, A. [Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006 Madrid (Spain)
2007-02-09
We study the low-lying baryon spectrum (up to 2.2 GeV) provided by experiments and different quark models using statistical tools which allow us to postulate the existence of missing levels in spectra. We confirm that the experimental spectrum is compatible with random matrix theory, the paradigmatic model of quantum chaos, and we find that the quark models are more similar to a Poisson distribution, which is not compatible with what should be expected in a correlated spectrum. From our analysis it stems that the spectral fluctuation properties of quark-model spectra are incompatible with experimental data. This result can be used to enlighten the problem of missing resonances.
Model-Independent Dark Energy Equation of State from Baryon Acoustic Oscillations
Evslin, Jarah
2015-01-01
We present a simple formula for the average dark energy equation of state at redshifts between those of two observations of baryon acoustic oscillations (BAO). The formula is independent of any parametrization or basis of the dark energy equation of state and essentially independent of the cosmological model. We use this formula to study the well-known tension between Lyman alpha forest BAO and other cosmological probes. Using only the line of sight Lyman alpha forest BAO and BOSS CMASS dataset, there is already more than 2 sigma tension with the standard LambdaCDM cosmological model which implies that either (i) The BOSS Lyman alpha forest measurement of the Hubble parameter was too low as a result of a statistical fluctuation or systematic error or else (ii) the dark energy equation of state falls steeply at high redshift.
Baryonic Matter Onset in Two-Color QCD with Heavy Quarks
Scior, Philipp
2015-01-01
We study the cold and dense regime in the phase diagram of two-color QCD with heavy quarks within a three-dimensional effective theory for Polyakov loops. This theory is derived from two-color QCD in a combined strong-coupling and hopping expansion. In particular, we study the onset of diquark density as the finite-density transition of the bosonic baryons in the two-color world. In contrast to previous studies of heavy dense QCD, our zero-temperature extrapolations are consistent with a continuous transition without binding energy. They thus provide evidence that the effective theory for heavy quarks is capable of describing the characteristic differences between diquark condensation in two-color QCD and the liquid-gas transition of nuclear matter in QCD.
Baryonic Matter Onset in Two-Color QCD with Heavy Quarks
Philipp Scior; Lorenz von Smekal
2015-08-03
We study the cold and dense regime in the phase diagram of two-color QCD with heavy quarks within a three-dimensional effective theory for Polyakov loops. This theory is derived from two-color QCD in a combined strong-coupling and hopping expansion. In particular, we study the onset of diquark density as the finite-density transition of the bosonic baryons in the two-color world. In contrast to previous studies of heavy dense QCD, our zero-temperature extrapolations are consistent with a continuous transition without binding energy. They thus provide evidence that the effective theory for heavy quarks is capable of describing the characteristic differences between diquark condensation in two-color QCD and the liquid-gas transition of nuclear matter in QCD.
Searching for onset of deconfinement via hypernuclei and baryon-strangeness correlations
S. Zhang; J. H. Chen; H. Crawford; D. Keane; Y. G. Ma; Z. B. Xu
2010-01-16
We argue that the ratio $S_3 =\\mathrm{^3_\\Lambda H} / (\\mathrm{^3He} \\times \\frac{\\Lambda}{p})$ is a good representation of the local correlation between baryon number and strangeness, and therefore is a valuable tool to probe the nature of the dense matter created in high energy heavy-ion collision: quark gluon plasma or hadron gas. A multiphase transport model (AMPT) plus a dynamical coalescence model is used to elucidate our arguments. We find that AMPT with string melting predicts an increase of $S_3$ with increasing beam energy, and is consistent with experimental data, while AMPT with only hadronic scattering results in a low $S_3$ throughout the energy range from AGS to RHIC, and fails to describe the experimental data.
Bridging Galaxy Dynamics and Baryon Efficiency of 40 EDGE-CALIFA galaxies
Kalinova, Veselina; Rosolowsky, Erik
2015-01-01
We apply the Jeans Axisymmetric Multi-Gaussian Expansion method to the stellar kinematic maps of 40 Sa-Sd EDGE-CALIFA galaxies and derive their circular velocity curves (CVCs). The CVCs are classified using the Dynamical Classification method developed in Kalinova et al. (2015) . We also calculate the observational baryon efficiency, OBE, where $M_*/M_b=M_*/(M_*+M_{HI}+M_{H_2})$ of the galaxies using their stellar mass, total neutral hydrogen mass and total molecular gas from CO luminosities. Slow-rising, Flat and Round-peaked CVC types correspond to specific OBEs, stellar and dark matter (DM) halo mass values, while the Sharp-peaked CVCs span in the whole DM halo mass range of $10^{11}-10^{14} M_{\\odot}$.
Regge Analysis of Diffractive and Leading Baryon Structure Functions from DIS
M. Batista; R. J. M. Covolan; J. Montanha
2002-03-08
In this paper we present a combined analysis of the H1 data on leading baryon and diffractive structure functions from DIS, which are handled as two components of the same semi-inclusive process. The available structure function data are analyzed in a series of fits in which three main exchanges are taking into account: pomeron, reggeon and pion. For each of these contributions, Regge factorization of the correspondent structure function is assumed. By this procedure, we extract information about the interface between the diffractive, pomeron-dominated, region and the leading proton spectrum, which is mostly ruled by secondary exchanges. One of the main results is that the relative reggeon contribution to the semi-inclusive structure function is much smaller than the one obtained from a analysis of the diffractive structure function alone.
manipulating cytosolic PPi content can
Kronzucker, Herbert J.
content and starch degradation during storage of tubers harvested from different potato varieties. Potato. et al. (1994) Possible involvement of abscisic acid, ethylene and phenolic acids in potato tuber
Measurement of the B_{-c}meson lifetime in the decay B_{-c}?J/???
Aaltonen, T.; Álvarez González, B.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bisello, D.; Bizjak, I.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Buzatu, A.; Calamba, A.; Calancha, C.; Camarda, S.; Campanelli, M.; Campbell, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Carron, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cavalli-Sforza, M.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Chlebana, F.; Cho, K.; Chokheli, D.; Chung, W. H.; Chung, Y. S.; Ciocci, M. A.; Clark, A.; Clarke, C.; Compostella, G.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Crescioli, F.; Cuevas, J.; Culbertson, R.; Dagenhart, D.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Dell’Orso, M.; Demortier, L.; Deninno, M.; Devoto, F.; d’Errico, M.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; D’Onofrio, M.; Donati, S.; Dong, P.; Dorigo, M.; Dorigo, T.; Ebina, K.; Elagin, A.; Eppig, A.; Erbacher, R.; Errede, S.; Ershaidat, N.; Eusebi, R.; Farrington, S.; Feindt, M.; Fernandez, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Frank, M. J.; Franklin, M.; Freeman, J. C.; Funakoshi, Y.; Furic, I.; Gallinaro, M.; Garcia, J. E.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Giannetti, P.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Giurgiu, G.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Goldschmidt, N.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Grinstein, S.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Halkiadakis, E.; Hamaguchi, A.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, D.; Hare, M.; Harr, R. F.; Hatakeyama, K.; Hays, C.; Heck, M.; Heinrich, J.; Herndon, M.; Hewamanage, S.; Hocker, A.; Hopkins, W.; Horn, D.; Hou, S.; Hughes, R. E.; Hurwitz, M.; Husemann, U.; Hussain, N.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Khotilovich, V.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. B.; Kim, S. H.; Kim, Y. K.; Kim, Y. J.; Kimura, N.; Kirby, M.; Klimenko, S.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Krop, D.; Kruse, M.; Krutelyov, V.; Kuhr, T.; Kurata, M.; Kwang, S.; Laasanen, A. T.; Lami, S.; Lammel, S.; Lancaster, M.; Lander, R. L.; Lannon, K.; Lath, A.; Latino, G.; LeCompte, T.; Lee, E.; Lee, H. S.; Lee, J. S.; Lee, S. W.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lin, C.-J.; Lindgren, M.; Lipeles, E.; Lister, A.; Litvintsev, D. O.; Liu, C.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maeshima, K.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Margaroli, F.; Marino, C.; Martínez, M.; Mastrandrea, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McFarland, K. S.; McIntyre, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Mondragon, M. N.; Moon, C. S.; Moore, R.; Morello, M. J.; Morlock, J.; Movilla Fernandez, P.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Neubauer, M. S.; Nielsen, J.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagan Griso, S.; Pagliarone, C.; Palencia, E.; Papadimitriou, V.; Paramonov, A. A.; Patrick, J.; Pauletta, G.; Paulini, M.; Paus, C.; Pellett, D. E.; Penzo, A.; Phillips, T. J.; Piacentino, G.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Prokoshin, F.; Pranko, A.; Ptohos, F.; Punzi, G.; Rahaman, A.; Ramakrishnan, V.; Ranjan, N.; Redondo, I.; Renton, P.; Rescigno, M.; Riddick, T.; Rimondi, F.; Ristori, L.; Robson, A.; Rodrigo, T.; Rodriguez, T.; Rogers, E.; Rolli, S.; Roser, R.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Safonov, A.; Sakumoto, W. K.
2013-01-01
The lifetime of the B_{-c} meson is measured using 272 exclusive B_{-c}?J/?(?????)?? decays reconstructed in data from proton-antiproton collisions corresponding to an integrated luminosity of 6.7 fb?¹ recorded by the CDF II detector at the Fermilab Tevatron. The lifetime of the B_{-c}meson is measured to be _{?}(B_{-c})=0.452±0.048(stat)±0.027(syst) ps. This is the first measurement of the B_{-c} meson lifetime in a fully reconstructed hadronic channel, and it agrees with previous results and has comparable precision.
Probing dark energy with baryonic oscillations and future radio surveys of neutral Hydrogen
F. B. Abdalla; S. Rawlings
2004-11-12
Current surveys may be on the verge of measuring the baryonic oscillations in the galaxy power spectrum which are clearly seen imprinted on the Cosmic Microwave Background. It has recently been proposed that these oscillations allow a `standard ruler' method of probing the equation of state of dark energy. In this paper we present a new calculation of the number of galaxies future adio telescopes will detect in surveys of the sky in neutral Hydrogen (HI). We estimate the likely statistical errors if the standard ruler method were to be applied to such surveys. We emphasise uncertainties in our calculations, and pinpoint the most important features of future HI surveys if they are to provide new constraints on dark energy via baryonic oscillations. Designs of future radio telescopes are required to have a large bandwidth (characterised by \\beta$, the ratio of the instantaneous bandwidth to the bandwidth required by survey) and to have the widest instantaneous (1.4 GHz) field of view ($FOV$) possible. Given the expected sensitivity of a future Square Kilometre Array (SKA), given that half of its collecting area will be concentrated in a core of diameter $\\sim 5 ~ \\rm km$, and given a reasonable survey duration ($T_0$ $\\sim$ 1 yr), we show that there will be negligible shot noise on a power spectrum derived from HI galaxies out to redshift $z \\simeq 1.5$. To access the largest cosmic volume possible by surveying all the sky available, we argue that $\\beta$, $T_0$ and $FOV$ must obey the relation $\\beta FOV T_0 \\gtsimeq 10 \\rm deg^2$ yr. An $\\sim$1-yr SKA survey would then contain $\\gtsimeq 10^{9} (f_{\\rm sky}/0.5)$ HI galaxies and provide constraints on the dark-energy parameter $w$ of order $\\Delta w \\simeq 0.01 (f_{\\rm sky}/0.5)^{-0.5}$.
Estimate of the Hadronic Production of the Doubly Charmed Baryon $?_{cc}$ under GM-VFN Scheme
Chao-Hsi Chang; Cong-Feng Qiao; Jian-Xiong Wang; Xing-Gang Wu
2006-01-05
Hadronic production of the doubly charmed baryon $\\Xi_{cc}$ ($\\Xi^{++}_{cc}$ and $\\Xi^{+}_{cc}$) is investigated under the general-mass variable-flavor-number (GM-VFN) scheme. The gluon-gluon fusion mechanism and the intrinsic charm mechanisms, i.e. via the sub-processes $g+g\\to(cc)[^3S_1]_{\\bar 3}+\\bar{c}+\\bar{c}$, $g+g\\to(cc)[^1S_0]_6+\\bar{c}+\\bar{c}$; $g+c\\to (cc)[^3S_1]_{\\bar 3}+\\bar{c}$, $g+c\\to (cc)[^1S_0]_6+\\bar{c}$ and $c+c\\to (cc)[^3S_1]_{\\bar 3}+g$, $c+c\\to (cc)[^1S_0]_6+g$, are taken into account in the investigation, where $(cc)[^3S_1]_{\\bar 3}$ (in color {\\bf $\\bar 3$}) and $(cc)[^1S_0]_6$ (in color {\\bf 6}) are two possible $S$-wave configurations of the doubly charmed diquark pair $(cc)$ inside the baryon $\\Xi_{cc}$. Numerical results for the production at hadornic colliders LHC and TEVATRON show that both the contributions from the doubly charmed diquark pairs $(cc)[^1S_0]_6$ and $(cc)[^3S_1]_{\\bar 3}$ are sizable with the assumption that the two NRQCD matrix elements are equal, and the total contributions from the `intrinsic' charm mechanisms are bigger than those of the gluon-gluon fusion mechanism. For the production in the region of small transverse-momentum $p_t$, the intrinsic mechanisms are dominant over the gluon-gluon fusion mechanism and they can raise the theoretical prediction of the $\\Xi_{cc}$ by almost one order.
Montgomery, Noel Davis
1993-01-01
The Clinton P. Anderson Meson Physics Facility (LAMPF) is an 800 megaelectron volt (MeV) proton accelerator operated by the University of California for the United States Department of Energy (DOE). The accelerator produces ...
Production of $K^-$-mesons in proton-proton and proton-nucleus interactions at various energies
S. V. Efremov; E. Ya. Paryev
1995-07-17
The experimental data on the production of $K^-$-mesons in pp-collisions are analyzed and a method of the unified description of these data in a broad energy range for primary protons is proposed. The $K^-$-mesons production in pA-collisions is considered. The simple formulas for inclusive cross sections of the $K^-$ production in these collisions are given. The results of the calculations by these formulas are compared with the available experimental data.
R. Czyzykiewicz
2007-02-06
The analysing power measurements for the p(pol)p -> pp eta reaction studied in this dissertation are used in the determination of the reaction mechanism of the eta meson production in nucleon-nucleon collisions. Measurements have been performed in the close-to-threshold energy region at beam momenta of p(beam)=2.010 and 2.085 GeV/c, corresponding to the excess energies of Q = 10 and 36 MeV, respectively. The experiments were realised by means of a cooler synchrotron and storage ring COSY along with a cluster jet target. For registration of the reaction products the COSY-11 facility has been used. The identification of the eta meson has been performed with the missing mass method. The results for the angular dependence of the analysing power combined with the hitherto determined isospin dependence of the total cross section for the $\\eta$ meson production in the nucleon-nucleon collisions, reveal a statistically significant indication that the excitation of the nucleon to the S_{11} resonance, the process which intermediates the production of the eta meson, is predominantly due to the exchange of a pi meson between the colliding nucleons. The determined values of the analysing power at both excess energies are consistent with zero implying that the eta meson is produced predominantly in the s-wave at both excess energies.
Moments of $\\phi$ meson spectral functions in vacuum and nuclear matter
Gubler, Philipp
2015-01-01
Moments of the $\\phi$ meson spectral function in vacuum and in nuclear matter are analyzed, combining a model based on chiral SU(3) effective field theory (with kaonic degrees of freedom) and finite-energy QCD sum rules. For the vacuum we show that the spectral density is strongly constrained by a recent accurate measurement of the $e^+ e^- \\to K^+ K^-$ cross section. In nuclear matter the $\\phi$ spectrum is modified by interactions of the decay kaons with the surrounding nuclear medium, leading to a significant broadening and an asymmetric deformation of the $\\phi$ meson peak. We demonstrate that both in vacuum and nuclear matter, the first two moments of the spectral function are compatible with finite-energy QCD sum rules. A brief discussion of the next-higher spectral moment involving strange four-quark condensates is also presented.
Fejos, G
2015-01-01
Temperature dependence of the $U_A(1)$ anomaly is investigated by taking into account mesonic fluctuations in the $U(3)\\times U(3)$ linear sigma model. A field dependent anomaly coefficient function of the effective potential is calculated within the finite temperature functional renormalization group approach. The applied approximation scheme is a generalization of the chiral invariant expansion technique developed in [G. Fej\\H{o}s, Phys. Rev. D 90, 096011 (2014)]. We provide an analytic expression and also numerical evidence that depending on the relationship between the two quartic couplings, mesonic fluctuations can either strengthen of weaken the anomaly as a function of the temperature. Role of the six-point invariant of the $U(3)\\times U(3)$ group, and therefore the stability of the chiral expansion is also discussed in detail.
G. Fejos
2015-08-31
Temperature dependence of the $U_A(1)$ anomaly is investigated by taking into account mesonic fluctuations in the $U(3)\\times U(3)$ linear sigma model. A field dependent anomaly coefficient function of the effective potential is calculated within the finite temperature functional renormalization group approach. The applied approximation scheme is a generalization of the chiral invariant expansion technique developed in [G. Fejos, Phys. Rev. D 90, 096011 (2014)]. We provide an analytic expression and also numerical evidence that depending on the relationship between the two quartic couplings, mesonic fluctuations can either strengthen of weaken the anomaly as a function of the temperature. The role of the six-point invariant of the $U(3)\\times U(3)$ group, and therefore the stability of the chiral expansion is also discussed in detail.
G. Fejos
2015-06-29
Temperature dependence of the $U_A(1)$ anomaly is investigated by taking into account mesonic fluctuations in the $U(3)\\times U(3)$ linear sigma model. A field dependent anomaly coefficient function of the effective potential is calculated within the finite temperature functional renormalization group approach. The applied approximation scheme is a generalization of the chiral invariant expansion technique developed in [G. Fejos, Phys. Rev. D 90, 096011 (2014)]. We provide an analytic expression and also numerical evidence that depending on the relationship between the two quartic couplings, mesonic fluctuations can either strengthen of weaken the anomaly as a function of the temperature. Role of the six-point invariant of the $U(3)\\times U(3)$ group, and therefore the stability of the chiral expansion is also discussed in detail.
Photonuclear production of vector mesons in ultra-peripheral Pb-Pb collisions at the LHC
Joakim Nystrand; for the ALICE Collaboration
2014-10-31
Vector mesons are copiously produced in ultra-peripheral nucleus-nucleus collisions. In these collisions, the nuclei are separated by impact parameters larger than the sum of the nuclear radii, and the interaction is mediated by the electromagnetic field. The interaction effectively corresponds to a photonuclear interaction between a photon, generated from the electromagnetic field of one of the nuclei, and the target nucleus. The ALICE Collaboration has previously published results on exclusive J/psi photoproduction at mid and forward rapidities in Pb-Pb collisions. The cross section for this process is a particularly good measure of the nuclear gluon distribution. In this talk, the latest results on exclusive production of light and heavy vector mesons from ALICE in Pb-Pb collisions will be presented.
Gluon contribution to open heavy meson production in heavy-ion collisions
Cao, Shanshan; Wang, Xin-Nian
2015-01-01
A sizable contribution to heavy quark production in high-energy hadronic and nuclear collisions comes from heavy quark-antiquark pair production from gluon splitting during the parton shower evolution. We investigate the effect of gluon-medium interaction on open heavy flavor spectra in ultra-relativistic heavy-ion collisions. The interaction of hard gluons and heavy quarks with the hot QCD medium is simulated utilizing a Langevin transport model that simultaneously incorporates contributions from collisional and radiative processes. It is found that while the gluon splitting channel has quite important contribution to single D meson production cross section, its influence on the final heavy meson nuclear modification turns out to be quite modest due to the short average lifetime of hard gluons before splitting to heavy quark pairs during the evolution and propagation of the parton shower.
Lepton Flavor Non-Universality in B-meson Decays from a U(2) Flavor Model
Falkowski, Adam; Ziegler, Robert
2015-01-01
We address the recent anomalies in semi-leptonic $B$-meson decays using a model of fermion masses based on the $U(2)$ flavor symmetry. The new contributions to $b \\to s \\ell \\ell$ transitions arise due to a tree-level exchange of a $Z^\\prime$ vector boson gauging a $U(1)$ subgroup of the flavor symmetry. They are controlled by a single parameter and are approximately aligned to the Standard Model prediction, with constructive interference in the $e$-channel and destructive interference in the $\\mu$-channel. The current experimental data on semi-leptonic $B$-meson decays can be very well reproduced without violating existing constraints from flavor violation in the quark and lepton sectors. Our model will be tested by new measurements of $b \\to s \\ell \\ell$ transitions and also by future electroweak precision tests, direct $Z^\\prime$ searches, and $\\mu$-$e$ conversion in nuclei.
Lepton Flavor Non-Universality in B-meson Decays from a U(2) Flavor Model
Adam Falkowski; Marco Nardecchia; Robert Ziegler
2015-09-03
We address the recent anomalies in semi-leptonic $B$-meson decays using a model of fermion masses based on the $U(2)$ flavor symmetry. The new contributions to $b \\to s \\ell \\ell$ transitions arise due to a tree-level exchange of a $Z^\\prime$ vector boson gauging a $U(1)$ subgroup of the flavor symmetry. They are controlled by a single parameter and are approximately aligned to the Standard Model prediction, with constructive interference in the $e$-channel and destructive interference in the $\\mu$-channel. The current experimental data on semi-leptonic $B$-meson decays can be very well reproduced without violating existing constraints from flavor violation in the quark and lepton sectors. Our model will be tested by new measurements of $b \\to s \\ell \\ell$ transitions and also by future electroweak precision tests, direct $Z^\\prime$ searches, and $\\mu$-$e$ conversion in nuclei.
Quarkonia and heavy-light mesons in a covariant quark model
Leitão, Sofia; Peña, M T; Biernat, Elmar P
2015-01-01
Preliminary calculations using the Covariant Spectator Theory (CST) employed a scalar linear confining interaction and an additional constant vector potential to compute the mesonic mass spectra. In this work we generalize the confining interaction to include more general structures, in particular a vector and also a pseudoscalar part, as suggested by a recent study. A one-gluon-exchange kernel is also implemented to describe the short-range part of the interaction. We solve the simplest CST approximation to the complete Bethe-Salpeter equation, the one-channel spectator equation, using a numerical technique that eliminates all singularities from the kernel. The parameters of the model are determined through a fit to the experimental pseudoscalar meson spectra, with a good agreement for both quarkonia and heavy-light states.
Probe the QCD phase diagram with ?-mesons in high energy nuclear collisions
B. Mohanty; N. Xu
2009-01-03
High-energy nuclear collision provide a unique tool to study the strongly interacting medium. Recent results from the Relativistic Heavy Ion Collider (RHIC) on \\phi-meson production has revealed the formation of a dense partonic medium. The medium constituents are found to exhibit collective behaviour initiated due to partonic interactions in the medium. We present a brief review of the recent results on \\phi production in heavy-ion collisions at RHIC. One crucial question is where, in the phase diagram, does the transition happen for the matter changing from hadronic to partonic degrees of freedom. We discuss how \\phi-meson elliptic flow in heavy-ion collisions can be used for the search of the QCD phase boundary.
A Rosetta Stone Relating Conventions In Photo-Meson Partial Wave Analyses
A.M. Sandorfi, B. Dey, A. Sarantsev, L. Tiator, R. Workman
2012-04-01
A new generation of complete experiments in pseudoscalar meson photo-production is being pursued at several laboratories. While new data are emerging, there is some confusion regarding definitions of asymmetries and the conventions used in partial wave analyses (PWA). We present expressions for constructing asymmetries as coordinate-system independent ratios of cross sections, along with the names used for these ratios by different PWA groups.
Two-body B meson decays to eta and eta ': Observation of B ->eta ' K
Ammar, Raymond G.; Baringer, Philip S.; Bean, Alice; Besson, David Zeke; Coppage, Don; Darling, C.; Davis, Robin E. P.; Kotov, S.; Kravchenko, I.; Kwak, Nowhan; Zhou, L.
1998-04-01
In a sample of 6.6 x 10(6) produced B mesons we have observed decays B --> eta'K, with branching fractions B(B+ --> eta'K+)= (6.5(-1.4)(+1.5) +/- 0.9) X 10(-5) and B(B-0 --> eta'K-0) = (4.7(-2.0)(+2.7) +/- 0.9) X 10(-5). We have searched...
CLNS 98/1575 An Update on CLEO's Study of B Meson Decays 1
six to eight years, many general properties of B meson decay were measured at DORIS and CESR. In 1988 via the tree diagram. The listed branching fractions, for exÂ ample Br(B ! XlÅ¡) = (10:4 \\Sigma 0 over electron, muon and tau semileptonic decay is 2:3 \\Theta (10:4 \\Sigma 0:4) = (23:9 \\Sigma 0
Polarization Observables From The Photoproduction Of Omega-Mesons Using Linearly Polarized Photons
Martinez, Danny [Idaho State University, Pocatello, ID (United States); Cole, Philip L. [Idaho State University, Pocatello, ID (United States)
2014-01-01
We report on the extraction of Polarization Observables Spin Density Matrix Elements (SDMEs), and Beam Asymmetry Sigma for omega meson photoproduction using a beam of linearly polarized photons in the photon energy region of Egamma = 1.3 to 1.7 GeV, by means of the angular distributions of the daughter pions from omega decay. These preliminary results are from the g8b dataset, which were collected with the CLAS detector in Hall B of Jefferson Lab.
P-wave heavy-light mesons using NRQCD and D234
Randy Lewis; R. M. Woloshyn
1999-09-13
The masses of S- and P-wave heavy-light mesons are computed in quenched QCD using a classically and tadpole-improved action on anisotropic lattices. Of particular interest are the splittings among P-wave states, which have not yet been resolved experimentally; even the ordering of these states continues to be discussed in the literature. The present work leads to upper bounds for these splittings, and is suggestive, but not conclusive, about the ordering.
Current algebra based effective chiral theory of mesons and a new EW theory
Bing An Li
2005-09-08
A current algebra based effective chiral theory of pseudoscalar, vector, axial-vector mesons is reviewed. A new mechanism generating the masses and guage fixing terms of gauge boson is revealed from this effective theory. A EW theory without Higgs is proposed. The masses and gauge fixing terms of W and Z are dynamically generated. Three heavy scalar fields are dynamically generated too. They are ghosts.
Measurement of D-meson production in p-Pb collisions with the ALICE detector
Grazia Luparello
2013-10-07
The ALICE Collaboration has measured the production of prompt D mesons in pPb collisions at sqrt(s_NN) = 5.02 TeV in the rapidity range -0.04 K-pi+, D+->K- pi+ pi+, D*+->D0 pi+ and Ds->phi pi+. The pT-differential production cross sections and the pT-dependent nuclear modification factors with respect to a proton-proton reference, RpPb, are presented.
Inclusive Production of {rho}{+-}(770) Meson in Hadronic Decays of Z0 Boson
Beddall, A.; Beddall, A.; Binguel, A.
2007-04-23
The inclusive production of the charged vector meson {rho}{+-}(770) in hadronic Z decays is measured with the ALEPH detector at the LEP collider. Decays of {rho}{+-} {yields} {pi}0 + {pi}{+-} are reconstructed for x > 0.05 where x = E{rho}/Ebeam. The results are compared with Monte Carlo model predictions and OPAL measurements. Bose-Einstein effects are found to be important in extracting {rho}{+-}(770) from two pion invariant mass spectra.
Relativistic Hartree-Fock-Bogoliubov Theory With Density Dependent Meson Couplings in Axial Symmetry
Ebran, J.-P.; Khan, E.; Arteaga, D. Pena; Grasso, M.; Vretenar, D.
2009-08-26
Most nuclei on the nuclear chart are deformed, and the development of new RIB facilities allows the study of exotic nuclei near the drip lines where a successful theoretical description requires both realistic pairing and deformation approaches. Relativistic Hartree-Fock-Bogoliubov model taking into account axial deformation and pairing correlations is introduced. Preliminary illustrative results with density dependent meson-nucleon couplings in axial symmetry will be discussed.
Liuming, Liu; Orginos, Kostas; Guo, Feng-Kun; Hanhart, Christoph; Meissner, Ulf-G.
2014-11-01
We study the scattering of light pseudoscalar mesons ( p , K ) off charmed mesons ( D , D s ) in full lattice QCD. The S -wave scattering lengths are calculated using Lüscher’s finite volume tech- nique. We use a relativistic formulation for the charm quark. For the light quark, we use domain- wall fermions in the valence sector and improved Kogut-Susskind sea quarks. We calculate the scattering lengths of isospin-3/2 D p , D s p , D s K , isospin-0 D ? K and isospin-1 D ? K channels on the lattice. For the chiral extrapolation, we use a chiral unitary approach to next-to-leading order, which at the same time allows us to give predictions for other channels. It turns out that our results support the interpretation of the D s 0 ( 2317 ) as a DK molecule. At the same time, we also update a prediction for the isospin breaking hadronic decay width G ( D s 0 ( 2317 ) ! D s p ) to ( 133 22 ) keV.
Weak axial nuclear heavy meson exchange currents and interactions of solar neutrinos with deuterons
B. Mosconi; P. Ricci; E. Truhlik
2007-02-28
Starting from the axial heavy meson exchange currents, constructed earlier in conjunction with the Bethe--Salpeter equation, we first present the axial $\\rho$--, $\\omega$-- and $a_1$ meson exchange Feynman amplitudes that satisfy the partial conservation of the axial current. Employing these amplitudes, we derive the corresponding weak axial heavy meson exchange currents in the leading order in the 1/M expansion ($M$ is the nucleon mass), suitable for the nuclear physics calculations beyond the threshold energies and with wave functions obtained by solving the Schr\\"odinger equation with one--boson exchange potentials. The constructed currents obey the nuclear form of the partial conservation of the axial current. We apply the space component of these currents in calculations of the cross sections for the disintegration of deuterons by low energy (anti)neutrinos. The deuteron and the final state nucleon--nucleon wave functions are derived (i) from a variant of the OBEPQB potential, and (ii) from the Nijmegen 93 and Nijmegen I nucleon-nucleon interaction. The extracted values of the constant $L_{1, A}$, entering the axial exchange currents of the pionless effective field theory, are in a reasonable agreement with its value predicted by the dimensional analysis.
Energies and radial distributions of B_s mesons on the lattice
J. Koponen
2007-03-09
This is a follow-up to our earlier work for the energies and the charge (vector) and matter (scalar) distributions for S-wave states in a heavy-light meson, where the heavy quark is static and the light quark has a mass about that of the strange quark. We now study excited states of these mesons with higher angular momentum and with radial nodes. The calculation is carried out with dynamical fermions on a 16^3 times 32 lattice with a lattice spacing approximately 0.10 fm. The lattice configurations were generated by the UKQCD Collaboration. Attempts are now being made to understand these results in terms of the Dirac equation. In nature the closest equivalent of this heavy-light system is the B_s meson, which allows us to compare our lattice calculations to experimental results (where available) or give a prediction where the P-wave states should lie. We pay particular attention to the spin-orbit splitting, to see which one of the states (for a given angular momentum L) has the lower energy.
S and P-wave heavy-light mesons in lattice NRQCD
Randy Lewis; R. M. Woloshyn
2000-10-02
The mass spectrum of S and P-wave mesons containing a single heavy quark is computed in the quenched approximation, using NRQCD up to third order in the inverse heavy quark mass expansion. Previous results found third order contributions which are as large in magnitude as the total second order contribution for the charmed S-wave spin splitting. The present work considers variations such as anisotropic lattices, Landau link tadpole improvement, and a highly-improved light quark action, and finds that the second order correction to the charmed S-wave spin splitting is about 20% of the leading order contribution, while the third order correction is about 20%(10%) for D^*-D(D_s^*-D_s). Nonleading corrections are very small for the bottom meson spectrum, and are statistically insignificant for the P-wave charmed masses. The relative orderings among P-wave charmed and bottom mesons, and the sizes of the mass splittings, are discussed in light of experimental data and existing calculations.
Possible relevance of softening of sigma meson to $\\eta$ decay into 3$\\pi$ in nuclear medium
Sakai, Shuntaro
2015-01-01
We investigate the role for the softening of the scalar-isoscalar (sigma) meson in the $\\eta\\rightarrow\\pi^+\\pi^-\\pi^0$ and $3\\pi^0$ decay widths in the symmetric nuclear medium using a linear sigma model. Our calculation shows that these decay widths in the nuclear medium increase by up to a factor of four to ten compared with those in the free space mainly depending on the mass of the sigma meson in the free space which is an input parameter of the model. The enhancements are considerable even at a half of the normal nuclear density. Thus, the $\\eta$ decay into $3\\pi$ can be a new possible probe for the chiral restoration in the nuclear medium. We find that the density dependence of the $\\eta\\rightarrow3\\pi^0$ decay is moderate in comparison with that of the $\\eta\\rightarrow\\pi^+\\pi^-\\pi^0$ although the former width is greater than the latter one at a given density: This is because the softening of the sigma meson causes the cancellation of the terms appearing from the Bose symmetry in the $\\eta\\rightarrow3...
Ammar, Raymond G.; Ball, S.; Baringer, Philip S.; Coppage, Don; Copty, N.; Davis, Robin E. P.; Hancock, N.; Kelly, M.; Kwak, Nowhan; Lam, H.
1993-11-01
We observe the SIGMA(c)+ baryon decaying to LAMBDA(c)+pi0 and measure the mass difference M(SIGMA(c)+) - M(LAMBDA(c)+) to be 168.5 +/- 0.4 +/- 0.2 MeV/c2. We also measure the mass differences M(SIGMA(c)++) - M(LAMBDA(c)+) and M(SIGMA(c)0) - M(LAMBDA(c...
Table of Contents Deschutes Subbasin Plan
Table of Contents Deschutes Subbasin Plan Table of Contents Executive Summary 1. Purpose and Scope.1. Physical, Natural and Human Landscape ................................................2.1 2.2. Water, Table of Contents Page 1 #12;Table of Contents 7. Limiting Factors and Conditions .........
Regulations and Basic Information Table of Contents
Liskiewicz, Maciej
Regulations and Basic Information Table of Contents Safe and Effective Use.) for Various Quantities of Water