Average and recommended half-life values for two neutrino double beta decay

TL;DR

This paper consolidates and updates the half-life measurements for various isotopes undergoing two neutrino double beta decay, providing recommended values and analyzing nuclear matrix elements based on the latest data.

Contribution

It offers a comprehensive review and weighted average of half-life values for multiple isotopes, updating previous results and including new data for $^{136}$Xe.

Findings

Recommended half-life values for multiple isotopes.

Updated nuclear matrix element calculations.

Inclusion of new data for $^{136}$Xe.

Abstract

All existing positive results on two neutrino double beta decay in different nuclei were analyzed. Using the procedure recommended by the Particle Data Group, weighted average values for half-lives of $^{48}$Ca, $^{76}$Ge, $^{82}$Se, $^{96}$Zr, $^{100}$Mo, $^{100}$Mo - $^{100}$Ru ($0^+_1$), $^{116}$Cd, $^{130}$Te, $^{136}$Xe, $^{150}$Nd, $^{150}$Nd - $^{150}$Sm ($0^+_1$) and $^{238}$U were obtained. Existing geochemical data were analyzed and recommended values for half-lives of $^{128}$Te, and $^{130}$Ba are proposed. Given the measured half-life values, nuclear matrix elements were calculated using latest (more reliable and precise) values for phase space factor. Finally, previous results (PRC 81 (2010) 035501) were up-dated and results for $^{136}$Xe were added.