Finite Amplitude Method for Charge-Changing Transitions in Axially-Deformed Nuclei

TL;DR

This paper introduces a finite amplitude method for calculating charge-changing nuclear responses in deformed nuclei, enabling efficient computation of beta-decay rates and exploring the impact of tensor terms in Skyrme functionals.

Contribution

It presents a novel finite amplitude method tailored for axially-deformed nuclei, facilitating faster and more versatile calculations of nuclear charge-changing responses.

Findings

Tensor terms increase allowed beta-decay rates

Method is effective for both spherical and deformed nuclei

Highlights importance of time-odd terms in nuclear functionals

Abstract

We describe and apply a version of the finite amplitude method for obtaining the charge-changing nuclear response in the quasiparticle random phase approximation. The method is suitable for calculating strength functions and beta-decay rates, both allowed and forbidden, in axially-deformed open-shell nuclei. We demonstrate the speed and versatility of the code through a preliminary examination of the effects of tensor terms in Skyrme functionals on beta decay in a set of spherical and deformed open-shell nuclei. Like the isoscalar pairing interaction, the tensor terms systematically increase allowed beta-decay rates. This finding generalizes previous work in semimagic nuclei and points to the need for a comprehensive study of time-odd terms in nuclear density functionals.