Ponente
Descripción
The monopole-driven shell evolution has been revealed in the south of doubly magic $^{132}$Sn for both neutron and proton shells. From the neutron shell side, an inversion of the $3/2^{+}$ and $11/2^{-}$ state, which corresponds to the neutron $d_{3/2}$ and $h_{11/2}$ orbitals, respectively, from $^{131}Sn_{81}$ to $^{129}Cd_{81}$, has been discovered in a recent mass measurement. According to the trend, the splitting between neutron $d_{3/2}$ and $h_{11/2}$ orbitals is getting larger from $^{129}$Cd$_{81}$ to $^{127}$Pd$_{81}$ where the $3/2^{+}$ state has not been discovered yet. From the proton shell side, a reduction of $Z$ = 40 sub-shell gap, which is formed by proton $p_{1/2}$ and $g_{9/2}$ orbitals, was suggested at $N$ = 82 in Ag isotopes by an extrapolation from the last known data point at $^{125}$Ag. The $1/2^{-}$ state has not been discovered yet in $^{127}$Ag. According to the systematics, long-lived beta isomers $3/2^{+}$ and $11/2^{-}$ are expected in $^{127}$Pd and $1/2^{-}$ and $9/2^{+}$ are expected in $^{127}$Ag. By establishing the beta-decay level scheme through the $^{127}$Pd $\rightarrow$ $^{127}$Ag $\rightarrow$ $^{127}$Cd decay chain, combined with possible mass measurements using MR-TOF-MS, we can assess whether a significant change occurs in the proton subshell gap and neutron major shell gap in this region.
