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Nuclear Theory·nucl-th

Thursday·July 23, 2015

6 papers—2 primary·4 cross-listed

All6Primary2Cross-lists4
  1. 01

    [Submitted on 22 Jul 2015]

    Neutrino emissivity in the quark-hadron mixed phase of neutron stars

    William M. Spinella (1,2)🇺🇸 · Fridolin Weber (2,3)🇺🇸 · Gustavo A. Contrera (4,5,6)🇦🇷 · Milva G. Orsaria (4,6) ((1) Computational Science Research Center San Diego State University, San Diego, CA, USA, (2) Department of Physics, San Diego State University, San Diego, CA, USA, (3) Center for Astrophysics and Space Sciences, University of California San Diego, La Jolla, CA, USA, (4) CONICET, Rivadavia 1917, Buenos Aires, Argentina, (5) IFLP, CONICET - Dpto. de Fisica, UNLP, La Plata, Argentina, (6) Grupo de Gravitacion, Astrofisica y Cosmologia, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosqu, La Plata, Argentina.)🇦🇷

    Numerous theoretical studies using various equation of state models have shown that quark matter may exist at the extreme densities in the cores of high-mass neutron stars. It has also been shown that a phase transition from hadronic matter to quark matter would result in an extended mixed phase region that would segregate phases by net charge to minimize the total energy of the phase, leading to the formation of a crystalline lattice. The existence of quark matter in the core of a neutron star may have significant consequences for its thermal evolution, which for thousands of years is facilitated primarily by neutrino emission. In this work we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the core. To this end we calculate the equation of state using the relativistic mean-field approximation to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. Next we determine the extent of the quark-hadron mixed phase and its crystalline structure using the Glendenning construction, allowing for the formation of spherical blob, rod, and slab rare phase geometries. Finally we calculate the neutrino emissivity due to electron-lattice interactions utilizing the formalism developed for the analogous process in neutron star crusts. We find that the contribution to the neutrino emissivity due to the presence of a crystalline quark-hadron mixed phase is substantial compared to other mechanisms at fairly low temperatures ( K) and quark fractions (), and that contributions due to lattice vibrations are insignificant compared to static-lattice contributions.

    Comments:
    12 pages, 10 figures; accepted for publication in the European Physical Journal A - "Hadrons and Nuclei."
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1507.06067 [pdf]
    EPJA(2016)·18 citations
  2. 02

    [Submitted on 22 Jul 2015]

    Self-consistent Theory of Finite Fermi Systems vs Skyrme-Hartree-Fock method. Spherical nuclei

    E.E. Saperstein · S.V. Tolokonnikov

    Recent results of the Fayans energy density functional (EDF) for spherical nuclei are reviewed. A comparison is made with predictions of several Skyrme EDFs. The charge radii and characteristics of the first 2^+ excitations in semi-magic nuclei are briefly discussed. The single-particle spectra of doubly magic nuclei are considered in more detail. The phonon-particle coupling effects are analyzed including the so-called tadpole term.

    Comments:
    6 pages, 7 figures, to appear in the proceedings of the International Conference "Nuclear Structure and Relaited Topics", July 14 - July 18, 2015, Dubna, Russia. arXiv admin note: text overlap with arXiv:1401.1319
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1507.06134 [pdf]
    EPJ Web Conf.(2016)·5 citations
  3. 03

    [Submitted on 21 Jul 2015] (cross-list from cond-mat.quant-gas)

    Lattice Boltzmann simulations of a two-dimensional Fermi gas at unitarity

    Jasmine Brewer · Miller Mendoza · Ryan E. Young · Paul Romatschke

    We present fully nonlinear dissipative fluid dynamics simulations of a trapped two-dimensional Fermi gas at unitarity using a Lattice Boltzmann algorithm. We are able to simulate non-harmonic trapping potentials, temperature-dependent viscosities as well as a discretized version of the ballistic (non-interacting) behavior. Our approach lends itself to direct comparison with experimental data, opening up the possibility of a precision determination of transport coefficients in the unitary Fermi gas. Furthermore, we predict the presence of a non-hydrodynamic component in the quadrupole mode, which should be observable experimentally.

    Comments:
    16 pages, 10 figures
    Subjects:
    Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
    arXiv:
    1507.05975 [pdf]
    PRA(2016)·14 citations
  4. 04

    [Submitted on 21 Jul 2015] (cross-list from hep-ph)

    Fluctuations and the rapidity dependence of charged particles spectra in fixed centrality bins in p collisions

    Larry McLerran🇺🇸 · Michal Praszalowicz🇵🇱

    We argue that large fluctuations in the saturation momentum are necessary to explain the ATLAS and ALICE data on pA collisions measured at the LHC. Using a form for the distribution of fluctuations motivated by theoretical studies of the non-linear evolution equations for the Color Glass Condensate, we find a remarkably good agreement between theory and the measured distributions. If the saturation momentum fluctuates, we argue that the cross section for a proton probe should also fluctuate, consistent with previous observations. Finally we discuss these results and their possible consistency with what is known about multiplicity fluctuations in such collisions, and attempts to describe the ridge effect from properties of the initial state.

    Comments:
    New title, 16 pages, 7 figures, to appear in Annals of Physics
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1507.05976 [pdf]
    Annals Phys.(2016)·17 citations
  5. 05

    [Submitted on 21 Jul 2015] (cross-list from hep-ph)

    Initial-state cold nuclear matter energy loss effects on inclusive jet production in p+A collisions at RHIC and LHC

    Zhong-Bo Kang🇺🇸 · Ivan Vitev🇺🇸 · Hongxi Xing🇺🇸

    Recent measurements of the centrality and rapidity dependence of single inclusive jet production in p+Pb collisions at the LHC have revealed large and non-trivial nuclear modification of the production cross section for this process. In this paper, we explore to what extent such nuclear modification can be understood by the framework of standard cold nuclear matter effects, in particular initial-state cold nuclear matter energy loss. We demonstrate quantitatively that theoretical calculations which include medium-induced radiative corrections can describe rather reasonably the attenuation of the jet production yields in the large transverse momentum region in d+Au collisions at RHIC and p+Pb collisions at the LHC for central to semi-central collisions. We further show that the observed scaling behavior of the nuclear modification factor as a function of the total jet energy for various rapidity intervals has a natural explanation in the picture of cold nuclear matter energy loss. On the other hand, the observed enhancement in peripheral collisions is not described in this picture and could have a different origin.

    Comments:
    11 pages, 7 eps figures; discussion in text and conclusions added
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1507.05987 [pdf]
    PRC(2015)·53 citations
  6. 06

    [Submitted on 22 Jul 2015] (cross-list from hep-ph)

    Influence of clustering and hadron potentials on the rapidity distribution of protons from the UrQMD model

    Qingfeng Li🇨🇳 · Yongjia Wang🇨🇳 · Xiaobao Wang🇨🇳 · Caiwan Shen🇨🇳 · Marcus Bleicher🇩🇪

    The Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model supplemented by potentials for both pre-formed hadrons and confined baryons (called UrQMD/M) are used to describe rapidity distributions of both the E895 proton data at AGS energies and the NA49 net proton data at SPS energies. With the help of a coalescence afterburner using only one parameter set of (, )=(3.8 fm, 0.3 GeVc), both sets of experimental data can be described fairly well except for a small discrepancy seen for the net protons at mid-rapidity from heavy ion collisions (HICs) at high SPS energies. Furthermore, in contrast to the logarithmic dependence with beam energy at SIS energies there are still about 10 of protons in clusters from central HICs at the beam energy of GeVnucleon.

    Comments:
    9 pages, 3 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1507.06033 [pdf]
    7 citations

Affiliations

first authorsco-authorsvia INSPIRE