Large-scale shell-model calculations on nuclei around mass 210

Large-scale shell-model calculations are performed for heavy nuclei with Z  82 around ²⁰⁸Pb. One feature for nuclei in this mass region is the existence of a lot of low-lying negative parity states. The low-lying 3^- states which are made by the core excitations are found in several nuclei. In contrast, it is known that the several 3^- states are lowered by the collective octupole correlation among valence nucleons. However, the theoretical investigations in this region are not enough so that the microscopic structures of these nuclei have not been clarified yet.

In this study, shell-model calculations are performed for even-even, odd-mass, and doubly-odd nuclei of Pt, Au, Hg, Tl, Pb, Bi, Po, At, Rn, and Fr isotopes assuming ²⁰⁸Pb as a doubly magic core. As  for a phenomenological interaction, one set of the two-body interaction strengths, which consists of the multipole-paring interactions including the monopole pairing and quadrupole-quadrupole interactions, is employed for all the nuclei considered. Energy spectra and electromagnetic properties are calculated and compared with the experimental data. In addition, several typical isomers are investigated. Part of this work is presented in Ref. [1].

[1] E. Teruya, K. Higashiyama, and N. Yoshinaga,  Phys. Rev. C 93, 064327 (2016).