Speaker
Description
Bound-state $\beta^-$-decay is a rare radioactive process where the created electron is trapped in an atomic orbital instead of being emitted. It can be observed in highly ionized atoms in particular when normal beta-decay is energetically forbidden, but bound-state decay is still possible. In this work, we present a systematic study on the bound-state $\beta^-$-decay of $^{202,204,205}$Tl using a theoretical framework analogous to that employed for electron-capture, treating the process as the time-mirrored orbital electron-capture. The key nuclear inputs are the nuclear matrix elements, which are determined within the nuclear shell model using a refined effective interaction. A good agreement between the measured and calculated half-life for $^{205}$Tl is obtained. In addition, we investigate the $\beta^-$-decay of $^{204}$Tl and electron-capture of $^{201,202,203,205}$Pb. Our results offer a systematic approach for evaluating bound-state $\beta^-$-decay rates and provide improved predictions for highly ionized atoms in astrophysical studies.