Shell-model-based investigation on level density of Xe and Ba isotopes

Abstract

Nuclear level density is important for evaluating nuclear reaction processes, but its microscopic investigation is not frequently performed. The present work applies a recently developed shell-model-based method to estimate the level density of fission products $^{133--137}\mathrm{Xe}$ and $^{135--138}\mathrm{Ba}$. The monopole-based universal interaction, ${V}_{\text{MU}}$, and the M3Y type spin-orbit interaction are combined to construct the shell-model Hamiltonian. The model space is truncated based on the binding energy of each configuration, estimated from the monopole interaction. The calculated level densities of $^{133--137}\mathrm{Xe}$ and $^{135--138}\mathrm{Ba}$ are in good agreement with available experimental data. The effects of spin-orbit and tensor forces on the nuclear level density and the shell effects in the spin distribution are discussed.