Half‐lives of $N = 126$ Isotones and the r‐Process Available to Purchase

Beta decays of $N = 126$ isotones are studied by shell model calculations. Both the Gamow‐Teller (GT) and first‐forbidden (FF) transitions are taken into account to evaluate the half‐lives of the isotones $(Z = 64–72)$ with the use of shell model interactions based on G‐matrix. The FF transitions are found to be important to reduce the half‐lives by twice to several times of those obtained 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.