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Title: Medium polarization and pairing in asymmetric nuclear matter

Abstract

The many-body theory of asymmetric nuclear matter is developed beyond the Brueckner–Hartree–Fock approximation to incorporate the medium polarization effects. The extension is performed within the Babu–Brown induced interaction theory. After deriving the particle–hole interaction in the form of Landau–Migdal parameters, the effects of the induced component on the symmetry energy are investigated along with the screening of {sup 1}S{sub 0} proton–proton and {sup 3}PF{sub 2} neutron–neutron pairing, which are relevant for the neutron-star cooling. The crossover from repulsive (screening) to attractive (anti-screening) interaction going from pure neutron matter to symmetric nuclear matter is discussed.

Authors:
 [1];  [2];  [3];  [1]
  1. Chinese Academy of Science, Institute of Modern Physics (China)
  2. Dipartimento di Fisica e Astronomia, and INFN-LNS (Italy)
  3. Lanzhou University, School of Nuclear Science and Technology (China)
Publication Date:
OSTI Identifier:
22613999
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 80; Journal Issue: 1; Other Information: Copyright (c) 2017 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; HARTREE-FOCK METHOD; MANY-BODY PROBLEM; NEUTRON STARS; NEUTRON-NEUTRON INTERACTIONS; NUCLEAR MATTER; PAIRING INTERACTIONS; PARTICLE-HOLE MODEL; POLARIZATION; PROTON-PROTON INTERACTIONS; SYMMETRY

Citation Formats

Dong, J. M., Lombardo, U., E-mail: lombardo@lns.infn.it, Zhang, H. F., and Zuo, W. Medium polarization and pairing in asymmetric nuclear matter. United States: N. p., 2017. Web. doi:10.1134/S1063778817010069.
Dong, J. M., Lombardo, U., E-mail: lombardo@lns.infn.it, Zhang, H. F., & Zuo, W. Medium polarization and pairing in asymmetric nuclear matter. United States. doi:10.1134/S1063778817010069.
Dong, J. M., Lombardo, U., E-mail: lombardo@lns.infn.it, Zhang, H. F., and Zuo, W. Sun . "Medium polarization and pairing in asymmetric nuclear matter". United States. doi:10.1134/S1063778817010069.
@article{osti_22613999,
title = {Medium polarization and pairing in asymmetric nuclear matter},
author = {Dong, J. M. and Lombardo, U., E-mail: lombardo@lns.infn.it and Zhang, H. F. and Zuo, W.},
abstractNote = {The many-body theory of asymmetric nuclear matter is developed beyond the Brueckner–Hartree–Fock approximation to incorporate the medium polarization effects. The extension is performed within the Babu–Brown induced interaction theory. After deriving the particle–hole interaction in the form of Landau–Migdal parameters, the effects of the induced component on the symmetry energy are investigated along with the screening of {sup 1}S{sub 0} proton–proton and {sup 3}PF{sub 2} neutron–neutron pairing, which are relevant for the neutron-star cooling. The crossover from repulsive (screening) to attractive (anti-screening) interaction going from pure neutron matter to symmetric nuclear matter is discussed.},
doi = {10.1134/S1063778817010069},
journal = {Physics of Atomic Nuclei},
number = 1,
volume = 80,
place = {United States},
year = {Sun Jan 15 00:00:00 EST 2017},
month = {Sun Jan 15 00:00:00 EST 2017}
}
  • Nuclear matter calculations show the quasi-deuteron pairing mode to be the most important one and to furnish values of the pairing fields that are in reasonable agreement with the recent measurements. Here, we study the effects of temperature on normal and quasi-deuteron pairing in asymmetric nuclear matter, using a Bonn-type meson exchange interaction.
  • We reexamine effects of the {rho}-{omega} meson mixing mediated by nucleon polarizations on the symmetry energy in isospin-asymmetric nuclear matter. Taking into account the rearrangement term neglected in previous studies by others, we evaluate the {rho}-{omega} mixing angle in a novel way within the relativistic mean-field models with and without chiral limits. It is found that the symmetry energy is significantly softened at high densities contrary to the finding in earlier studies. As the first step of going beyond the lowest-order calculations, we also solve the Dyson equation for the {rho}-{omega} mixing. In this case, it is found that themore » symmetry energy is not only significantly softened by the {rho}-{omega}mixing at suprasaturation densities, similar to the lowest-order {rho}-{omega} mixing, but interestingly also softened at subsaturation densities. In addition, the softening of the symmetry energy at subsaturation densities can be partly suppressed by the nonlinear self-interaction of the {sigma} meson.« less
  • In this paper, we calculate properties of the spin polarized asymmetrical nuclear matter and neutron star matter, using the lowest order constrained variational (LOCV) method with the AV{sub 18}, Reid93, UV{sub 14}, and AV{sub 14} potentials. According to our results, the spontaneous phase transition to a ferromagnetic state in the asymmetrical nuclear matter as well as neutron star matter do not occur.
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