From credible shell model interactions to neutron-capture uncertainties

TL;DR

This paper presents the first uncertainty-quantified neutron-capture cross section for $^{27}$Al, derived from shell model calculations of nuclear level densities and radiative strength functions, highlighting the impact of model uncertainties.

Contribution

It introduces a novel approach to quantify uncertainties in neutron-capture cross sections using shell model predictions of nuclear properties.

Findings

USDBUQ500 interaction predicts NLDs and RSFs with 6% and 9% uncertainties.

Uncertainty in cross section ranges from 5% to 25%.

Cross section distribution is non-Gaussian.

Abstract

Nuclear structure theory can provide nuclear astrophysics and nuclear technologies with bound state properties and transition rates. When describing nuclear reactions, the list can be extended to include statistical properties such as nuclear level densities (NLDs) and radiative strength functions (RSFs). We present the first uncertainty-quantified neutron-capture cross section for $^{27}$Al based on NLDs and RSFs computed with the shell model (SM). We find that the USDBUQ500 SM interaction predicts NLDs and RSFs with constant uncertainties of 6% and 9%, respectively. These, in turn, translate to a 5 to 25% uncertainty in the neutron-capture cross section, which exhibits a surprisingly non-Gaussian distribution.