New Calculations for Phase Space Factors Involved in Double Beta Decay

TL;DR

This paper provides improved calculations of phase space factors for double beta decay, incorporating detailed electron wave function distortions due to Coulomb effects, nuclear size, and electron screening, enhancing accuracy for experimental analysis.

Contribution

It introduces a comprehensive numerical method for calculating phase space factors in double beta decay, considering realistic nuclear and electron interactions, which improves upon previous approximations.

Findings

New phase space factors for various isotopes

Comparison showing differences with prior results

Discussion of factors affecting calculation accuracy

Abstract

We present new results for the phase space factors involved in double beta decay for beta-beta- transitions to ground states and excited 0+1 states, for isotopes of experimental interest. The Coulomb distortion of the electron wave functions is treated by solving numerically the Dirac equation with inclusion of the finite nuclear size and electron screening effects, and using a Coulomb potential derived from a realistic proton density distribution in the daughter nucleus. Our results are compared with other results from literature, obtained in different approximations, and possible causes that can give differences are discussed.