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Nuclear Theory·nucl-th

Tuesday·April 14, 2015

14 papers—5 primary·9 cross-listed

All14Primary5Cross-lists9
  1. 01

    [Submitted on 10 Apr 2015]

    Many-body forces, isospin asymmetry and dense hyperonic matter

    R.O. Gomes🇩🇪 · V. Dexheimer🇺🇸 · S. Schramm🇩🇪 · C.A.Z. Vascconcellos🇧🇷

    The equation of state (EoS) of asymmetric nuclear matter at high densities is a key topic for the description of matter inside neutron stars. The determination of the properties of asymmetric nuclear matter, such as the symmetry energy () and the slope of the symmetry energy () at saturation density, has been exaustively studied in order to better constrain the nuclear matter EoS. However, differently from symmetric matter properties that are reasonably constrained, the symmetry energy and its slope still large uncertainties in their experimental values. Regarding this subject, some studies point towards small values of the slope of the symmetry energy, while others suggest rather higher values. Such a lack of agreement raised a certain debate in the scientific community. In this paper, we aim to analyse the role of these properties on the behavior of asymmetric hyperonic matter. Using the formalism presented in Ref. (R.O. Gomes et al 2014}, which considers many-body forces contributions in the meson-baryon coupling, we calculate the EoS of asymmetric hyperonic matter and apply it to describe hyperonic matter and hyperon stars.

    Comments:
    7 pages, contribution to Proceedings of the workshop "Compact Stars in the QCD phase diagram IV", Prerow, Germany, September 26 - 30, 2014
    Subjects:
    Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
    arXiv:
    1504.02788 [pdf]
    0 citations
  2. 02

    [Submitted on 10 Apr 2015]

    Condition for the burning of hadronic stars into quark stars

    A. Drago🇮🇹 · G. Pagliara🇮🇹

    We will review the approach used for studying the conversion of a hadronic star into a quark star based on the assumption of a infinitely thin combustion zone and we will discuss why, in this scheme, the combustion stops before the whole hadronic star is converted.

    Comments:
    6 pages, 1 figure, contribution to Proceedings of the workshop "Compact Stars in the QCD phase diagram IV", Prerow, Germany, September 26 - 30, 2014
    Subjects:
    Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR)
    arXiv:
    1504.02795 [pdf]
    4 citations
  3. 03

    [Submitted on 11 Apr 2015]

    R-Matrix description of particle energy spectra produced by low-energy T+T reactions

    C.R. Brune · J.A. Caggiano · D.B. Sayre · A.D. Bacher · G.M. Hale · M.W. Paris

    An R-matrix model for three-body final states is presented and applied to a recent measurement of the neutron energy spectrum from the T+T->2n+alpha reaction. The calculation includes the n-alpha and n-n interactions in the final state, angular momentum conservation, antisymmetrization, and the interference between different channels. A good fit to the measured spectrum is obtained, where clear evidence for the 5He ground state is observed. The model is also used to predict the alpha-particle spectrum from T+T as well as particle spectra from 3He+3He. The R-matrix approach presented here is very general, and can be adapted to a wide variety of problems with three-body final states.

    Comments:
    31 pages, 17 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1504.02821 [pdf]
    PRC(2015)·17 citations
  4. 04

    [Submitted on 13 Apr 2015]

    Spectroscopy of quadrupole and octupole states in rare-earth nuclei from a Gogny force

    K. Nomura🇫🇷 · R. Rodríguez-Guzmán🇰🇼 · L. M. Robledo🇪🇸

    Collective quadrupole and octupole states are described in a series of Sm and Gd isotopes within the framework of the interacting boson model (IBM), whose Hamiltonian parameters are deduced from mean field calculations with the Gogny energy density functional. The link between both frameworks is the () potential energy surface computed within the Hartree-Fock-Bogoliubov framework in the case of the Gogny force. The diagonalization of the IBM Hamiltonian provides excitation energies and transition strengths of an assorted set of states including both positive and negative parity states. The resultant spectroscopic properties are compared with the available experimental data and also with the results of the configuration mixing calculations with the Gogny force within the generator coordinate method (GCM). The structure of excited states and its connection with double octupole phonons is also addressed. The model is shown to describe the empirical trend of the low-energy quadrupole and octupole collective structure fairly well, and turns out to be consistent with GCM results obtained with the Gogny force.

    Comments:
    17 pages, 12 figures, 4 tables
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1504.03243 [pdf]
    PRC(2015)·61 citations
  5. 05

    [Submitted on 13 Apr 2015]

    Properties of nuclei in the nobelium region studied within the covariant, Skyrme, and Gogny energy density functionals

    J. Dobaczewski · A.V. Afanasjev · M. Bender · L.M. Robledo · Yue Shi

    We calculate properties of the ground and excited states of nuclei in the nobelium region for proton and neutron numbers of 92 <= Z <= 104 and 144 <= N <= 156, respectively. We use three different energy-density-functional (EDF) approaches, based on covariant, Skyrme, and Gogny functionals, each within two different parameter sets. A comparative analysis of the results obtained for odd-even mass staggerings, quasiparticle spectra, and moments of inertia allows us to identify single-particle and shell effects that are characteristic to these different models and to illustrate possible systematic uncertainties related to using the EDF modelling

    Comments:
    43 LaTeX pages, 14 figures, accepted in Nuclear Physics A, Special Issue on Superheavy Elements
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1504.03245 [pdf]
    NPA(2015)·74 citations

Affiliations

first authorsco-authorsvia INSPIRE