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Nuclear Theory·nucl-th

Thursday·January 5, 2017

5 papers—4 primary·1 cross-listed

All5Primary4Cross-lists1
  1. 01

    [Submitted on 3 Jan 2017]

    Non-coherent character of isoscalar pairing probed with Gamow-Teller strength: New insight into C dating decay

    Yutaka Utsuno · Yoshitaka Fujita

    We investigate the phase coherence of isoscalar pairs from the values in two-particle configurations of , 18, and 42 nuclei and two-hole configurations of and 38 ones. We find that these Gamow-Teller (GT) matrix elements are always constructive and thus enlarged under isovector- and isoscalar-pairing Hamiltonians, whereas the observed GT strengths are strongly hindered for the two-hole configurations, including the famous C dating decay. This indicates that the actual isoscalar pair, unlike the isovector pair, has no definite phase coherence, which can work against forming isoscalar-pair condensates.

    Comments:
    5 pages, 3 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1701.00869 [pdf]
    3 citations
  2. 02

    [Submitted on 4 Jan 2017]

    Hyperon polarization in Heavy-Ion Collisions and gravity-related anomaly

    Mircea Baznat🇷🇺 · Konstantin Gudima🇲🇩 · Alexander Sorin🇷🇺 · Oleg Teryaev🇷🇺

    We study the energy dependence of global polarization of hyperons in peripheral collisions. We combine the calculation of vorticity and strange chemical potential in the framework of kinetic Quark-Gluon String Model with the anomalous mechanism related to axial vortical effect. The earlier found effect of helicity separation implies the quadrupole structure of longitudinal vorticity. We pay special attention to the temperature dependent contribution related to gravitational anomaly and found that the preliminary RHIC data are compatible with its suppression discovered earlier in lattice calculations. The antihyperons polarization is excessing that of hyperons and the difference is more pronounced at smaller energies.

    Comments:
    11 pages, 4 figures; new figures, discussion, references and acknowledgments added
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1701.00923 [pdf]
    PRC(2018)·73 citations
  3. 03

    [Submitted on 4 Jan 2017]

    Towards a self-consistent dynamical nuclear model

    X. Roca-Maza · Y.F. Niu · G. Colò · P. F. Bortignon

    Density Functional Theory (DFT) is a powerful and accurate tool exploited in Nuclear Physics to investigate the ground-state and some collective properties of nuclei along the whole nuclear chart. Models based on DFT are, however, not suitable for the description of single-particle dynamics in nuclei. Following the field theoretical approach by A. Bohr and B. R. Mottelson to describe nuclear interactions between single-particle and vibrational degrees of freedom, we have undertaken important steps to build a microscopic dynamic nuclear model. In connection to that, one important issue that needs to be better understood is the renormalization of the effective interaction in the particle-vibration approach. One possible way to renormalize the interaction is the so called {\it subtraction method}. In this contribution we will implement the {\it subtraction method} for the first time in our model and study its consequences.

    Comments:
    JPhysG. Accepted paper (https://doi.org/10.1088/1361-6471/aa5669). Special issue (http://iopscience.iop.org/journal/0954-3899/page/Emerging%20Leaders)
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1701.00924 [pdf]
    J.Phys.G(2017)·25 citations
  4. 04

    [Submitted on 3 Jan 2017]

    Resonant nuclear reaction Mg Al in strongly screening magnetized neutron star crust

    Jing-Jing Liu · Dong-Mei Liu

    Basing on the relativistic theory in superstrong magnetic fields (SMFs), we investigate the influence of strong electron screening (SES) on the rates of nuclear reaction Mg Al by three models of Lai (LD), Fushiki et al. (FGP), and Liu et al. (LJ) on the surface of magnetars. Our results show that the rates can be greatly enhanced by three orders of magnitude due to the influence of SES. The rates in our model are in good agreement with those of LD and FGP at relatively low density environment (e.g. ) for . On the other hand, in relatively high magnetic fields (e.g. ), the rates of our model can be 1.58 times and around three orders of magnitude larger than those of FGP and LD, respectively. The significant increase of the rates of our model for Mg Al implies that more Mg will escape from the Ne-Na cycle due to SES in SMFs. As a consequence, the next reaction Al Mg will produce more Mg to participate in the Mg-Al cycle. Thus, it may lead to synthesize a large amount of production of nuclides (e.g. Al) on the surface of magnetars. These heavy elements (e.g. Al) may be thrown out due to the compact binary mergers of double neutron star (NS-NS) or black hole and neutron star (BH and NS) systems. Our results may help to understand why the Al is always overabundance in the interstellar space. Our conclusion may be helpful to the investigation of the nucleosynthesis of some heavy elements, the energy generation rate, and the numerical calculations of magnetars evolution.

    Comments:
    44 pages, 6 figures, Accepted for publication in Chinese Physics C
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1701.01088 [pdf]
    CPC(2017)·8 citations
  5. 05

    [Submitted on 4 Jan 2017] (cross-list from astro-ph.HE)

    From microphysics to dynamics of magnetars

    Armen Sedrakian · Xu-Guang Huang · Monika Sinha · John W. Clark

    MeV-scale magnetic fields in the interiors of magnetars suppress the pairing of neutrons and protons in the -wave state. In the case of a neutron condensate the suppression is the consequence of the Pauli-paramagnetism of the neutron gas, i.e., the alignment of the neutron spins along the magnetic field. The proton -wave pairing is suppressed because of the Landau diamagnetic currents of protons induced by the field. The Ginzburg-Landau and BCS theories of the critical magnetic fields for unpairing are reviewed. The macrophysical implications of the suppression (unpairing) of the condensates are discussed for the rotational crust-core coupling in magnetars and the neutrino-dominated cooling era of their thermal evolution.

    Comments:
    10 pages, 4 figures, Proceedings of "Compact Stars in the QCD phase diagram V", 23-27 May 2016 GSSI and LNGS, L'Aquila, Italy
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
    arXiv:
    1701.00895 [pdf]
    J.Phys.Conf.Ser.(2017)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE