Shell-model study for 204–210Tl isotopes and core excitations across the Z = 82 and N = 126 shell gaps

In the present work, the ^204–210Tl isotopes have been investigated by performing large-scale shell-model calculations, including configurations allowing both neutron and proton core excitations across the $Z=82$ and $N=126$ shell gaps. Inspired by the recent high-spin experimental data, the structure of Tl isotopes has been studied for a considerably large model space. The KHHE interaction has been used for ^204–206Tl isotopes, KHH7B interaction for ^204–210Tl isotopes, and additionally KHM3Y interaction has been used for ²⁰⁸Tl isotope. The core excitation has been performed using the KHH7B and KHM3Y interactions. The level spectra of ^204–210Tl isotopes are comprehensively described and explained by multi-nucleon couplings of single-particle-hole orbitals within the valence space and by core excitations across ²⁰⁸Pb core. The well-known isomeric states are analyzed in terms of the shell model configurations.