250 research outputs found

    Heavy Flavor Probes of Quark Matter

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    A brief survey of the role of heavy flavors as a probe of the state of matter produced by high energy heavy ion collisions is presented. Specific examples include energy loss, initial state gluon saturation, thermalization and flow. The formation of quarkonium bound states from interactions in which multiple heavy quark-antiquark pairs are initially produced is examined in general. Results from statistical hadronization and kinetic models are summarized. New predictions from the kinetic model for J/Psi at RHIC are presented.Comment: Based on invited plenary talk at Strange Quark Matter 2004, Cape Town, South Africa, September 15-20, 2004, references completed, published in J. Phys. G: Nucl. Part. Phys. 31 (2005) S641-S64

    Quarkonium Formation Time in a Model-Independent Approach

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    We use dispersion relations to reconstruct, in a model-independent way, the formation dynamics of heavy quarkonium from the experimental data on e+ e- annihilation to Q-bar Q. We extract a distribution of formation times with a mean value for the J/psi, tau{J/psi} = 0.44 fm; and for the Upsilon, tau{Upsilon} = 0.32 fm. The corresponding widths of these distributions are given by Delta-tau{J/psi} = 0.31 fm and Delta-tau{Upsilon} = 0.28 fm. This information can be used as an input in modeling of heavy quarkonium production on nuclear targets.Comment: 10 pages with 3 figure

    Meson PVV Interactions are determined by Quark Loops

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    We show that all abnormal parity three-body meson interactions can be adequately described by quark loops, evaluated at zero external momentum, with couplings determined by U(Nf)U(N_f) symmetry. We focus primarily on radiative meson decays which involve one pseudoscalar. The agreement with experiment for non-rare decays is surprisingly good and requires very few parameters, namely the coupling constants gπqqg_{\pi qq} and gρqqg_{\rho qq} and some mixing angles. This agreement extends to some three-body decays that are dominated by pion pairs in a P-wave state.Comment: 21 pages, Revtex, one figur

    An Experimental Overview of Results Presented at SQM 2006

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    I have been asked to give an critical overview on the experimental results shown in the conference with a emphasis of what has been learned and the challenges that are ahead in trying to understand the physics of the strongly interacting quark-gluon plasma. I will not try to summarize all of the results presented, rather I will concentrate primarily on RHIC data from this conference. Throughout this summary, I will periodically review some of the previous results for those not familiar with the present state of the field.Comment: 15 pages, 12 Figure

    Kaon Weak Decays in Chiral Theories

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    The ten nonleptonic weak decays K2πK \to 2\pi, K3πK \to 3\pi, KL2γK_L \to 2\gamma, KS2γK_S \to 2\gamma, KLπ2γK_L \to \pi^\circ 2\gamma, are predicted for a chiral pole model based on the linear sigma model theory which automatically satisfies the partial conservation of axial current (PCAC) hypothesis. These predictions, agreeing with data to the 5% level and containing no or at most one free parameter, are compared with the results of chiral perturbation theory (ChPT). The latter ChPT approach to one-loop level is known to contain at least four free parameters and then predicts a KLπγγK_L \to \pi^\circ \gamma\gamma rate which is 60% shy of the experimental value. This suggests that ChPT is an unsatisfactory approach towards predicting kaon weak decays.Comment: 12 pages, 8 eps figure

    Quark Matter and Nuclear Collisions: A Brief History of Strong Interaction Thermodynamics

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    The past fifty years have seen the emergence of a new field of research in physics, the study of matter at extreme temperatures and densities. The theory of strong interactions, quantum chromodynamics (QCD), predicts that in this limit, matter will become a plasma of deconfined quarks and gluons -- the medium which made up the early universe in the first 10 microseconds after the big bang. High energy nuclear collisions are expected to produce short-lived bubbles of such a medium in the laboratory. I survey the merger of statistical QCD and nuclear collision studies for the analysis of strongly interacting matter in theory and experiment.Comment: 24 pages, 14 figures Opening Talk at the 5th Berkeley School on Collective Dynamics in High Energy Collisions, LBNL Berkeley/California, May 14 - 18, 201

    Radiative decays of heavy and light mesons in a quark triangle approach

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    The radiative meson decays VPγV\to P\gamma and PγγP\to \gamma\gamma are analyzed using the quark triangle diagram. Experimental data yield well determined estimates of the universal quark-antiquark-meson couplings gVqqˉg_{Vq\bar{q}'} and gPqqˉg_{Pq\bar{q}'} for the light meson sector. Also predictions for the ratios of neutral to charged heavy meson decay coupling constants are given and await experimental confirmation.Comment: 31 pages of RevTex, 5 figures, Postscript version available at http://info.utas.edu.au/docs/physics/theory/Publications/9548.html, scheduled to appear in Phys. Rev. D, vol 53, issue 11, 199

    Heavy Flavor Hadrons in Statistical Hadronization of Strangeness-rich QGP

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    We study b, c quark hadronization from QGP. We obtain the yields of charm and bottom flavored hadrons within the statistical hadronization model. The important novel feature of this study is that we take into account the high strangeness and entropy content of QGP, conserving strangeness and entropy yields at hadronization.Comment: v2 expended: 20 pages, 23 figures, 5 tables, in press EPJ-

    Hard probes in heavy ion collisions at the LHC: heavy flavour physics

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    We present the results from the heavy quarks and quarkonia working group. This report gives benchmark heavy quark and quarkonium cross sections for pppp and pApA collisions at the LHC against which the AAAA rates can be compared in the study of the quark-gluon plasma. We also provide an assessment of the theoretical uncertainties in these benchmarks. We then discuss some of the cold matter effects on quarkonia production, including nuclear absorption, scattering by produced hadrons, and energy loss in the medium. Hot matter effects that could reduce the observed quarkonium rates such as color screening and thermal activation are then discussed. Possible quarkonium enhancement through coalescence of uncorrelated heavy quarks and antiquarks is also described. Finally, we discuss the capabilities of the LHC detectors to measure heavy quarks and quarkonia as well as the Monte Carlo generators used in the data analysis.Comment: 126 pages Latex; 96 figures included. Subgroup report, to appear in the CERN Yellow Book of the workshop: Hard Probes in Heavy Ion Collisions at the LHC. See also http://a.home.cern.ch/f/frixione/www/hvq.html for a version with better quality for a few plot

    Inelastic Final-State Interactions and Two-body Hadronic B decays into Single-Isospin channels

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    The role of inelastic final-state interactions in CP asymmetries and branching ratios is investigated in certain chosen single isospin two-body hadronic B decays. Treating final-state interactions through Pomeron and Regge exchanges, we demonstrate that inelastic final state interactions could lead to sizeable effects on the CP asymmetry.Comment: 23 pages, Latex, 1 eps-figur
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