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arXiv · 1702.00576

Temperature dependence of the symmetry energy and neutron skins in Ni, Sn, and Pb isotopic chains

A. N. Antonov·D. N. Kadrev·M. K. Gaidarov·P. Sarriguren·E. Moya de Guerra
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Abstract

The temperature dependence of the symmetry energy for isotopic chains of even-even Ni, Sn, and Pb nuclei is investigated in the framework of the local density approximation (LDA). The Skyrme energy density functional with two Skyrme-class effective interactions, SkM* and SLy4, is used in the calculations. The temperature-dependent proton and neutron densities are calculated through the HFBTHO code that solves the nuclear Skyrme-Hartree-Fock-Bogoliubov problem by using the cylindrical transformed deformed harmonic-oscillator basis. In addition, two other density distributions of $^{208}$Pb, namely the Fermi-type density determined within the extended Thomas-Fermi (TF) method and symmetrized-Fermi local density obtained within the rigorous density functional approach, are used. The kinetic energy densities are calculated either by the HFBTHO code or, for a comparison, by the extended TF method up to second order in temperature (with $T^{2}$ term). Alternative ways to calculate the symmetry energy coefficient within the LDA are proposed. The results for the thermal evolution of the symmetry energy coefficient in the interval $T=0-4$ MeV show that its values decrease with temperature. The temperature dependence of the neutron and proton root-mean-square radii and corresponding neutron skin thickness is also investigated, showing that the effect of temperature leads mainly to a substantial increase of the neutron radii and skins, especially in the more neutron-rich nuclei, a feature that may have consequences on astrophysical processes and neutron stars.

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A. N. Antonov, D. N. Kadrev, M. K. Gaidarov, P. Sarriguren, E. Moya de Guerra. 2017-02-02. Temperature dependence of the symmetry energy and neutron skins in Ni, Sn, and Pb isotopic chains. https://doi.org/10.1103/physrevc.95.024314

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