Beta Decays of Isotones with Neutron Magic Number of N=126 and R-process Nucleosynthesis

TL;DR

This study investigates beta decays of N=126 isotones using shell model calculations, highlighting the significance of first-forbidden transitions and their impact on r-process nucleosynthesis during supernovae.

Contribution

It introduces comprehensive shell model calculations including both Gamow-Teller and first-forbidden transitions for N=126 isotones, revealing their influence on decay half-lives and r-process element formation.

Findings

First-forbidden transitions significantly shorten half-lives.

Shorter half-lives affect the r-process abundance peaks.

A shift of the third abundance peak toward higher mass is observed.

Abstract

Beta decays of the isotones with N=126 are studied by shell model calculations taking into account both the Gamow-Teller (GT) and first-forbidden (FF) transitions. The FF transitions are found to be important to reduce the half-lives, by nearly twice to several times, from those by the GT contributions only. Possible implications of the short half-lives of the waiting point nuclei on the r-process nucleosynthesis during the supernova explosions are discussed. A slight shift of the third peak of the element abundances in the r-process toward higher mass region is found.