Neutrino absorption by hot nuclei in supernova environments

TL;DR

This study investigates how hot nuclei in supernova environments absorb neutrinos and antineutrinos, emphasizing thermal effects on transition strengths and cross sections using advanced nuclear models.

Contribution

It applies the thermal quasiparticle random phase approximation to analyze thermal effects on neutrino capture on hot nuclei, providing detailed cross section calculations for supernova conditions.

Findings

Thermal effects significantly enhance low-energy neutrino cross sections.

Allowed and forbidden transitions both contribute to the capture process.

Comparison with shell-model calculations validates the approach for $^{56}$Fe.

Abstract

Using the thermal quasiparticle random phase approximation, we study the process of neutrino and antineutrino capture on hot nuclei in supernova environments. For the sample nuclei $^{56}$Fe and $^{82}$Ge we perform a detailed analysis of thermal effects on the strength distribution of allowed Gamow-Teller transitions which dominate low-energy charged-current neutrino reactions. The finite temperature cross sections are calculated taking into account the contributions of both allowed and forbidden transitions. The enhancement of the low-energy cross sections is explained by considering thermal effects on the GT$_\pm$ strength. For $^{56}$Fe we compare the calculated finite-temperature cross sections with those obtained from large-scale shell-model calculations.