Shell-model-based investigation on level density of Xe and Ba isotopes
Jinbei Chen, Menglan Liu, Cenxi Yuan, Shengli Chen, Noritaka Shimizu, Xiao-Dong Sun, Ruirui Xu, Yuan Tian
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.