Electron angular correlation in neutrinoless double beta decay and new physics

TL;DR

This paper calculates the electron angular correlation in neutrinoless double beta decay considering various physical effects and demonstrates its independence from nuclear matrix element models, providing insights into new physics scenarios.

Contribution

It introduces a comprehensive calculation of angular correlations in $0 u2eta$ decay including recoil, wave effects, and electron mass, applicable across different new physics models.

Findings

Angular coefficient is largely model-independent.

Provides angular correlation predictions for left-right symmetric models.

Enhances understanding of $0 u2eta$ decay signatures.

Abstract

The angular correlation of the electrons in the neutrinoless double beta decay ($0\nu2\beta$) is calculated taking into account the nucleon recoil, the $S$ and $P$-waves for the electrons and the electron mass using a general Lorentz invariant effective Lagrangian. We show that the angular coefficient is essentially independent of the nuclear matrix element models. We work out the angular coefficient in several scenarios for new physics, in particular, in the left-right symmetric models.