PaperPanorama

Nuclear Theory·nucl-th

Tuesday·December 9, 2014

9 papers5 primary·4 cross-listed

  1. 06

    [Submitted on 7 Dec 2014] (cross-list from hep-ph)

    Polyakov SU(3) extended linear -model: Sixteen mesonic states in chiral phase-structure

    Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo and WLCAPP, Cairo)🇪🇬 · Abdel Magied Diab (Egyptian Ctr. Theor. Phys., Cairo and WLCAPP, Cairo)🇪🇬

    The derivative of the grand potential in mean field approximation, non-strange and strange condensates and deconfinement phase-transition in thermal and dense hadronic medium are verified in extended SU(3) linear sigma-model (eLSM). In determining the chiral phase-transition, the chiral condensates sigma_x and sigma_y are analysed. The chiral mesonic phase-structures in temperature- and density-dependence are taken as free parameters to be fitted. These parameters are classified corresponding to scalar meson nonets; (pseudo)-scalar and (axial)-vector. For deconfinement phase-transition, effective Polyakov loop-potentials phi and phi^* are utilized. We investigated the in-medium effects on the masses of sixteen mesonic states states. The results are presented for two different forms for the effective Polyakov loop-potential and compared with other models with and without anomalous terms. The Polyakov loop potential in LSM has considerable effects on the chiral phase-transition in meson masses so that the restoration of the chiral symmetry becomes sharper and faster than LSM. We normalize all mesonic states with respect to the lowest Matsubara frequency. It has been found that the various mesonic states have different dissolving temperatures and chemical potentials, i.e. they survive the typically-averaged QCD phase boundary, defined by the QCD critical temperatures with varying chemical potentials. The thermal behavior of all meson masses has been investigated in the large- limit and found that the scalar meson masses are T-independent at large and high (except pi and sigma). For the pseudoscalar meson masses, the large N_c limit unifies the -dependence of all states in a universal bundle. The same is also observed for axial and axialvector meson masses in the large-N_c limit.

    Comments:
    46 pages, 20 figures with 84 eps graphs and 78 references, to appear in Phys. Rev. c
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1412.2395 [pdf]
    PRC(2015)·43 citations
  2. 07

    [Submitted on 7 Dec 2014] (cross-list from cond-mat.quant-gas)

    Stoner ferromagnetism of a strongly interacting Fermi gas in the quasirepulsive regime

    Lianyi He · Xia-Ji Liu · Xu-Guang Huang · Hui Hu

    Recent advances in rapidly quenched ultracold atomic Fermi gases near a Feshbach resonance have brought about a number of interesting problems, in the context of observing the long-sought Stoner ferromagnetic phase transition. The possibility of experimentally obtaining a "quasirepulsive" regime in the upper branch of the energy spectrum due to the rapid quench is currently being debated, and the Stoner transition has mainly been investigated theoretically by using perturbation theory or at high polarization, due to the limited theoretical approaches in the strongly repulsive regime. In this work, we present a nonperturbative theoretical approach to the quasirepulsive upper branch of a Fermi gas near a broad Feshbach resonance, and we determine the finite-temperature phase diagram for the Stoner instability. Our results agree well with the known quantum Monte-Carlo simulations at zero temperature, and we recover the known virial expansion prediction at high temperature for arbitrary interaction strengths. At resonance, we find that the Stoner transition temperature becomes of the order of the Fermi temperature, around which the molecule formation rate becomes vanishingly small. This suggests a feasible way to observe Stoner ferromagnetism in the nondegenerate temperature regime.

    Comments:
    Published version in Physical Review A
    Subjects:
    Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
    arXiv:
    1412.2412 [pdf]
    PRA(2016)·9 citations
  3. 08

    [Submitted on 8 Dec 2014] (cross-list from hep-ph)

    QCD Factorization and PDFs from Lattice QCD Calculation

    Yan-Qing Ma🇨🇳 · Jian-Wei Qiu🇺🇸

    In this talk, we review a QCD factorization based approach to extract parton distribution and correlation functions from lattice QCD calculation of single hadron matrix elements of quark-gluon operators. We argue that although the lattice QCD calculations are done in the Euclidean space, the nonperturbative collinear behavior of the matrix elements are the same as that in the Minkowski space, and could be systematically factorized into parton distribution functions with infrared safe matching coefficients. The matching coefficients can be calculated perturbatively by applying the factorization formalism on to asymptotic partonic states.

    Comments:
    8 pages, 2 figures, accepted contribution to the proceedings of "The QCD Evolution 2014 workshop", May 12-16, 2014, Santa Fe, NM
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    1412.2688 [pdf]
    Int.J.Mod.Phys.Conf.Ser.(2015)·57 citations
  4. 09

    [Submitted on 8 Dec 2014] (cross-list from hep-ph)

    Electron-Ion Collider - taking us to the next QCD frontier

    Jian-Wei Qiu🇺🇸

    In this talk, I demonstrate that the proposed Electron-Ion Collider (EIC) will be an ideal and unique future facility to address many overarching questions about QCD and strong interaction physics at one place. The EIC will be the world's first polarized electron-proton (and light ion), as well as the first electron-nucleus collider at flexible collision energies. With its high luminosity and beam polarization, the EIC distinguishes itself from HERA and the other fixed target electron-hadron facilities around the world. The EIC is capable of taking us to the next QCD frontier to explore the glue that binds us all.

    Comments:
    8 pages, 4 figures, accepted contribution to the proceedings of "The QCD Evolution 2014 workshop", May 12-16, 2014, Santa Fe, NM
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1412.2703 [pdf]
    Int.J.Mod.Phys.Conf.Ser.(2015)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE