Stellar electron-capture rates in pf-shell nuclei from quasiparticle random-phase approximation calculations

TL;DR

This paper calculates electron-capture rates for pf-shell nuclei relevant to presupernova conditions using a quasiparticle random-phase approximation, comparing results with experimental data and shell-model benchmarks.

Contribution

It introduces a deformed Skyrme Hartree-Fock based QRPA approach for electron-capture rates, incorporating pairing and residual interactions, and analyzes model dependence and sensitivities.

Findings

Energy distributions of Gamow-Teller strength match experimental data.

Weak rates show sensitivity to density and temperature variations.

Model dependence affects the accuracy of electron-capture rate predictions.

Abstract

Electron-capture rates at different density and temperature conditions are evaluated for a set of pf-shell nuclei representative of the constituents in presupernova formations. The nuclear structure part of the problem is described within a quasiparticle random-phase approximation based on a deformed Skyrme Hartree-Fock selfconsistent mean field with pairing correlations and residual interactions in particle-hole and particle-particle channels. The energy distributions of the Gamow-Teller strength are evaluated and compared to benchmark shell-model calculations and experimental data extracted from charge-exchange reactions. The model dependence of the weak rates are discussed and the various sensitivities to both density and temperature are analyzed.