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Nuclear Theory·nucl-th

Monday·October 8, 2018

13 papers—7 primary·6 cross-listed

All13Primary7Cross-lists6
  1. 01

    [Submitted on 5 Oct 2018]

    Coulomb exchange functional with generalized gradient approximation for self-consistent Skyrme Hartree-Fock calculations

    Tomoya Naito · Xavier Roca-Maza · Gianluca Colò · Haozhao Liang

    We perform the self-consistent Skyrme Hartree-Fock calculation with the Coulomb exchange functional in the form of generalized gradient approximation (GGA). It is found that the Perdew-Burke-Ernzerhof GGA (PBE-GGA) Coulomb exchange functional is able to reproduce the exact-Fock energy for the nuclei in a large region of the nuclear chart with one adjustable parameter. The remaining error of Coulomb exchange energy by the GGA with respect to the exact-Fock energy dominantly comes from the functional-driven error.

    Comments:
    22 pages, 6 figures, 3 tables
    Subjects:
    Nuclear Theory (nucl-th); cond-mat.other (cond-mat.other); Nuclear Experiment (nucl-ex)
    arXiv:
    1810.02500 [pdf]
    PRC(2019)·10 citations
  2. 02

    [Submitted on 5 Oct 2018]

    Cross sections of -induced reactions slightly below doubly-magic Ca from the statistical model

    P. Mohr · R. Talwar · M. L. Avila

    New experimental data for the Ar(,n)Ca and Ar(,p)K reactions were used to find a best-fit set of parameters for statistical model calculations. The very good agreement between the experimental data and the best-fit calculation confirms the applicability of the statistical model for nuclei in the vicinity of the doubly-magic Ca despite of their relatively low level densities. The present study investigates the sensitivities and finds that the -nucleus and the nucleon-nucleus potentials are the most important ingredients for the calculation of (,n) and (,p) reactions in the statistical model. Furthermore, the width fluctuation correction plays an essential role in the peculiar case of Ar. The best-fit parameters from Ar are applied to the mirror nucleus Ca and the neighboring Ar and Ar nuclei. For Ca this results in an astrophysical reaction rate of the Ca(,p)Sc reaction which has a flatter temperature dependence compared to all previous calculations. For Ar a better reproduction of Ar(,p)K data from literature is obtained. The disagreement between calculation and an early experimental data point for the Ar(,p)K reaction persists.

    Comments:
    14 pages, 10 figures; Phys. Rev. C, accepted for publication
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1810.02527 [pdf]
    PRC(2018)·4 citations
  3. 03

    [Submitted on 5 Oct 2018]

    Cluster structures in C from global energy density functionals

    Petar Marević🇫🇷 · Jean-Paul Ebran🇫🇷 · Elias Khan🇫🇷 · Tamara Nikšić🇭🇷 · Dario Vretenar🇭🇷

    Spectroscopic properties of low-lying states and cluster structures in C are analyzed in a "beyond mean-field framework" based on global energy density functionals (EDFs). To build symmetry-conserving collective states, axially-symmetric and reflection-asymmetric solutions of the relativistic Hartree-Bogoliubov equations are first projected onto good values of angular momentum, particle number, and parity. Configuration mixing is implemented using the generator coordinate method formalism. It is shown that such a global microscopic approach, based on a relativistic EDF, can account for the main spectroscopic features of C, including the ground-state and linear-chain bands as well as, to a certain approximation, the excitation energy of the Hoyle state. The calculated form factors reproduce reasonably well the available experimental values, and display an accuracy comparable to that of dedicated microscopic cluster models.

    Comments:
    10 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1810.02632 [pdf]
    PRC(2019)·30 citations
  4. 04

    [Submitted on 5 Oct 2018]

    How (not) to renormalize integral equations with singular potentials in effective field theory

    E. Epelbaum🇩🇪 · A. M. Gasparyan🇩🇪 · J. Gegelia🇩🇪 · Ulf-G. Meißner🇩🇪

    We discuss the connection between the perturbative and non-perturbative renormalization and related conceptual issues in the few-nucleon sector of the low-energy effective field theory of the strong interactions. General arguments are supported by examples from effective theories with and without pions as dynamical degrees of freedom. A quantum mechanical potential with explicitly specified short- and long-range parts is considered as an "underlying fundamental theory" and the corresponding effective field theory potential is constructed. Further, the problem of the effective field theoretical renormalization of the Skornyakov-Ter-Martyrosian equation is revisited.

    Comments:
    12 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th)
    arXiv:
    1810.02646 [pdf]
    EPJA(2018)·71 citations
  5. 05

    [Submitted on 5 Oct 2018]

    Advantages of the multinucleon transfer reactions based on 238U target for producing neutron-rich isotopes around N = 126

    Long Zhu · Cheng Li · Jun Su · Chen-Chen Guo · Wei Hua

    The mechanism of multinucleon transfer (MNT) reactions for producing neutron-rich heavy nuclei around N = 126 is investigated within two different theoretical frameworks: dinuclear system (DNS) model and isospin-dependent quantum molecular dynamics (IQMD) model. The effects of mass asymmetry relaxation, N=Z equilibration, and shell closures on production cross sections of neutron-rich heavy nuclei are investigated. For the first time, the advantages for producing neutron-rich heavy nuclei around N = 126 is found in MNT reactions based on 238U target. We propose the reactions with 238U target for producing unknown neutron-rich heavy nuclei around N = 126 in the future.

    Comments:
    6 pages, 6 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1810.02663 [pdf]
    PLB(2019)·26 citations
  6. 06

    [Submitted on 4 Oct 2018]

    Polarization and Chirality: the quantum features of the Quark Gluon Plasma

    F. Becattini🇮🇹

    Polarization and chirality are direct manifestations of quantum mechanics in the Quark Gluon Plasma as a relativistic fluid. This is one of the reasons why they are intriguing phenomena, that have attracted so much attention lately. In this talk I will review what is, in my view, the current theoretical understanding and highlight the most interesting recent result.

    Comments:
    7 pages, plenary talk given at the conference Quark Matter 2018. arXiv admin note: text overlap with arXiv:1711.08780
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1810.02706 [pdf]
    NPA(2019)·3 citations
  7. 07

    [Submitted on 5 Oct 2018]

    Proton-proton 1S0 pairing in neutron star

    Wenmei Guo🇨🇳 · J. M. Dong🇨🇳 · X. Shang🇨🇳 · H. F. Shang🇨🇳 · W. Zuo🇨🇳 · M. Colonna🇮🇹 · U. Lombardo🇮🇹

    The onset of 1S0 proton spin-singlet pairing in neutron-star matter is studied in the framework of the BCS theory including medium polarization effects. The strong three-body coupling of the diproton pairs with the dense neutron environment and the self-energy effects severely reduce the gap magnitude, so to reshape the scenario of the proton superfluid phase inside the star. The vertex corrections due to the medium polarization are attractive in all isospin-asymmetry range at low density and tend to favor the pairing in that channel. However quantitative estimates of their effect on the energy gap do not give significant changes. Implications of the new scenario on the role of pairing in neutron-star cooling is briefly discussed.

    Comments:
    5 pages, 5 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1810.02709 [pdf]
    NPA(2019)·12 citations

Affiliations

first authorsco-authorsvia INSPIRE