An effective method to accurately calculate the phase space factors for $\beta^- \beta^-$ decay

TL;DR

This paper introduces an efficient method for calculating electron phase space factors in double-beta decay, accounting for Coulomb distortions, to improve prediction accuracy of decay rates and electron distributions.

Contribution

The paper presents a new method that accurately incorporates Coulomb field distortions in phase space calculations, simplifying computations compared to existing approaches.

Findings

Method achieves high accuracy relative to exact calculations.

Enables reliable predictions of decay rates and electron distributions.

Simplifies phase space factor computations.

Abstract

Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates, and for the analysis of the associated electron angular and energy distributions. We present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.