Shape effects on double beta decay of $^{70}$Zn and $^{150}$Nd in deformed shell model

TL;DR

This paper investigates how nuclear shape deformation affects double beta decay matrix elements in $^{70}$Zn and $^{150}$Nd, showing that deformation significantly reduces these matrix elements compared to spherical shapes.

Contribution

It demonstrates, using the deformed shell model with two effective interactions, that nuclear deformation leads to a considerable reduction in double beta decay matrix elements.

Findings

Deformed shapes reduce decay matrix elements compared to spherical shapes.

Results are consistent across $^{70}$Zn and $^{150}$Nd examples.

Deformation effects are significant for double beta decay calculations.

Abstract

Using deformed shell model based on Hartree-Fock intrinsic states with $^{70}$Zn as an example and employing two realistic effective interactions, namely jj44b that produces deformed shape and JUN45 that generates spherical shape, it is demonstrated that the $0\nu$ and $2\nu$ nuclear transition matrix elements for double beta decay will reduce considerably as we go from spherical shapes to deformed shapes. This result is further substantiated by using $^{150}$Nd as another example.