Isomeric structure in the Sn100 region: Possible competition between β+ decay and proton emission in the isomeric unbound nucleus <mml:mmultiscripts…

The isomeric structure and properties in proton-rich nuclides are crucial for determining the path of the rapid proton capture process ($rp$-process). For example, bound nuclei inside the dripline can have unbound isomeric states and change the $rp$-process pathway. The configuration interaction shell model is used to investigate nuclei around the $Z=N$ line at the southwest region of ¹⁰⁰Sn. The excitation mechanism of 1/2₁^- isomers is identified as dominated by exciting one nucleon in the 1p1/2 orbit to the 0g9/2 orbit. The study explores the decay properties of both the ground and isomeric states. Remarkably, competitive β⁺ decay and proton emission are predicted in the unbound 1/2₁^- isomer of ⁹⁷Sn, suggesting potential influences on the $rp$-process pathway.