Thermal QRPA with Skyrme interactions and supernova neutral-current neutrino-nucleus reactions

TL;DR

This paper develops a method combining Thermal QRPA with Skyrme interactions to study neutrino interactions with hot nuclei relevant to supernovae, providing new insights into thermal effects on neutrino-nucleus reactions.

Contribution

The paper introduces a Skyrme-based Thermal QRPA approach to analyze thermal effects on neutrino-nucleus reactions, improving upon previous phenomenological models.

Findings

Calculated neutrino scattering cross sections at supernova temperatures.

Analyzed thermal effects on Gamow-Teller strength functions.

Compared results with previous phenomenological and hybrid models.

Abstract

The Thermal Quasiparticle Random-Phase Approximation is combined with the Skyrme energy density functional method (Skyrme-TQRPA) to study the response of a hot nucleus to an external perturbation. For the sample nuclei, $^{56}$Fe and $^{82}$Ge, the Skyrme-TQRPA is applied to analyze thermal effects on the strength function of charge-neutral Gamow-Teller transitions which dominate neutrino-nucleus reactions at $E_\nu \lesssim 20$~MeV. For the relevant supernova temperatures we calculate the cross sections for inelastic neutrino scattering. We also apply the method to examine the rate of neutrino-antineutrino pair emission by hot nuclei. The cross sections and rates are compared with those obtained earlier from the TQRPA calculations based on the phenomenological Quasiparticle-Phonon Model Hamiltonian. For inelastic neutrino scattering on $^{56}$Fe we also compare the Skyrme-TQRPA results to those obtained earlier from a hybrid approach that combines shell-model and RPA calculations.