Deformation effects on the Gamow-Teller strength distributions in the double-beta decay partners 76Ge and 76Se

TL;DR

This paper uses a deformed quasiparticle random phase approximation based on a Skyrme mean field to analyze how nuclear deformation affects Gamow-Teller strength distributions in 76Ge and 76Se, impacting double-beta decay calculations.

Contribution

It introduces a theoretical model that incorporates nuclear deformation effects into Gamow-Teller strength distribution analysis for double-beta decay partners 76Ge and 76Se.

Findings

Deformation significantly influences Gamow-Teller strength distributions.

The model accurately reproduces experimental measurements.

Nuclear deformation impacts the calculated nuclear matrix element.

Abstract

A theoretical approach based on a deformed quasiparticle random phase approximation built on a Skyrme selfconsistent mean field is used to describe the recent measurements of the Gamow-Teller GT- strength distribution extracted from the charge-exchange reaction 76Ge(3He,t)76As with high energy resolution. The same analysis is made to describe the Gamow-Teller GT+ strength distribution measured in the 76Se(d,2He)76As reaction. Combining these two branches, the nuclear matrix element for the two-neutrino double-beta decay process is evaluated and compared to experiment. The role of the nuclear deformation on those processes is emphasized and analyzed.