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Nuclear Theory·nucl-th

Wednesday·December 7, 2016

11 papers—6 primary·5 cross-listed

All11Primary6Cross-lists5
  1. 01

    [Submitted on 6 Dec 2016]

    Radiative 3He(2H,g)5Li capture at low deuterium energy

    Sergey Dubovichenko🇰🇿 · Nataliya Burkova🇰🇿 · Albert Dzhazairov-Kakhramanov🇰🇿

    The results are presented on the total cross sections, astrophysical S-factor, reaction rate of the deuteron radiative capture on 3He at the temperatures from 0.03 up to 3 T9 calculated in the framework of the potential cluster model with the forbidden states coming from the classification of the orbital states by the Young diagrams. Within the used model and exploited Young diagram classification made it possible to reproduce the general features of the available experimental data on the cross section and reconstructed astrophysical S-factor in the energy range from 200 keV up to 1.4 MeV. The parametrization of the obtained reaction rate has been found and been compared with some other actual reactions with light clusters.

    Comments:
    13p., 6 fig., 31 ref., 4 tab
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1612.01660 [pdf]
    Russ.Phys.J.(2017)·4 citations
  2. 02

    [Submitted on 6 Dec 2016]

    Ternary fission within the temperature dependent relativistic mean field approach

    M.T. Senthil Kannan · Bharat Kumar · M. Balasubramaniam · B. K. Agrawal · S. K. Patra

    For the first time, we apply the temperature dependent relativistic mean field (TRMF) model to study the ternary fission of heavy nucleus using level density approach. The probability of yields of a particular fragment is obtained by evaluating the convolution integrals which employ the excitation energy and the level density parameter for a given temperature calculated within the TRMF formalism. To illustrate, we have considered the ternary fissions in 252Cf, 242Pu and 236U with fixed third fragment A3 = 48Ca, 20O and 16O respectively. The relative yields are studied for the temperatures T = 1, 2 and 3 MeV. For the comparison, the relative yields are also calculated from the single particle energies of the finite range droplet model (FRDM). In general, the larger phase space for the ternary fragmentation is observed indicating that such fragmentations are most probable ones. For T = 2 and 3 MeV, the Sn + Ni + Ca is the most probable combination for the nucleus 252Cf. However, for the nuclei 242Pu and 236U, the maximum fragmentation yields at T = 2 MeV differ from those at T = 3 MeV. For T = 3 MeV, the closed shell (Z = 8) light mass fragments with its corresponding partners has larger yield values. But, at T = 2 MeV Si/P/S are favorable fragments with the corresponding partners. It is noticed that the symmetric binary fragmentation along with the fixed third fragment for 242Pu and 236U are also favored at T = 1 MeV. The temperature dependence of the nuclear shape and the single particle energies are also discussed.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1612.01667 [pdf]
    PRC(2017)·11 citations
  3. 03

    [Submitted on 6 Dec 2016]

    SQM2016: Theory Summary

    V. Greco🇮🇹

    This is an overview of the main theoretical developments presented at SQM2016 held in Berkeley, California (USA) in June 2015.

    Comments:
    6 pages, no figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    1612.01796 [pdf]
    J.Phys.Conf.Ser.(2017)·3 citations
  4. 04

    [Submitted on 6 Dec 2016]

    Supernova equations of state including full nuclear ensemble with in-medium effects

    Shun Furusawa · Kohsuke Sumiyoshi · Shoichi Yamada · Hideyuki Suzuki

    We construct new equations of state for baryons at sub-nuclear densities for the use in core-collapse supernova simulations. The abundance of various nuclei is obtained together with thermodynamic quantities. The formulation is an extension of the previous model, in which we adopted the relativistic mean field theory with the TM1 parameter set for nucleons, the quantum approach for , , and as well as the liquid drop model for the other nuclei under the nuclear statistical equilibrium. We reformulate the model of the light nuclei other than , , and based on the quasi-particle description. Furthermore, we modify the model so that the temperature dependences of surface and shell energies of heavy nuclei could be taken into account. The pasta phases for heavy nuclei and the Pauli- and self-energy shifts for , , and are taken into account in the same way as in the previous model. We find that nuclear composition is considerably affected by the modifications in this work, whereas thermodynamical quantities are not changed much. In particular, the washout of shell effect has a great impact on the mass distribution above MeV. This improvement may have an important effect on the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores.

    Comments:
    39 pages, 6 figures, 2 tables, Accepted for publication in Nucl.Phys. A. This article draws heavily from arXiv:1305.1508. The EOS table available at http://sites.google.com/site/furusawashun/eosdata
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    1612.01852 [pdf]
    NPA(2017)·58 citations
  5. 05

    [Submitted on 6 Dec 2016]

    Self consistent calculation of the nuclear composition in hot and dense stellar matter

    Shun Furusawa · Igor Mishustin

    We investigate the mass fractions and in-medium properties of heavy nuclei in stellar matter at characteristic densities and temperatures for supernova (SN) explosions. The individual nuclei are described within the compressible liquid-drop model taking into account modifications of bulk, surface and Coulomb energies. The equilibrium properties of nuclei and the full ensemble of heavy nuclei are calculated self-consistently. It is found that heavy nuclei in the ensemble are either compressed or decompressed depending on the isospin asymmetry of the system. The compression or decompression has a little influence on the binding energies, total mass fractions and average mass numbers of heavy nuclei, although the equilibrium densities of individual nuclei themselves are changed appreciably above one hundredth of normal nuclear density. We find that nuclear structure in single nucleus approximation deviates from the actual one obtained in the multi-nucleus description, since the density of free nucleons is different between these two descriptions. This study indicates that a multi-nucleus description is required to realistically account for in-medium effects on the nuclear structure in supernova matter.

    Comments:
    26 pages, 10 figures, accepted for publication in Phys. Rev. C
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
    arXiv:
    1612.01854 [pdf]
    PRC(2017)·14 citations
  6. 06

    [Submitted on 6 Dec 2016]

    Dipole-dipole dispersion interactions between neutrons

    James F. Babb · Renato Higa · Mahir S. Hussein

    We investigate the long-range interactions between two neutrons utilizing recent data on the neutron static and dynamic electric and magnetic dipole polarizabilities. The resulting long-range potentials are used to make quantitative comparisons between the collisions of a neutron with a neutron and a neutron with a proton. We also assess the importance of the first pion production threshold and first excited state of the nucleon, the -resonance ( = + 3/2, I = 3/2). We found both dynamical effects to be quite relevant for distances r between ~ 50 fm up to ~ fm in the nn system, the neutron-wall system and in the wall-neutron-wall system, reaching the expected asymptotic limit beyond that. Relevance of our findings to the confinement of ultra cold neutrons inside bottles is discussed.

    Comments:
    11 pages, 12 figures, Version to be published in the European Physical Journal A (2017)
    Subjects:
    Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    1612.01946 [pdf]
    EPJA(2017)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE