Ground-state inversion: The monopole-force governance in neutron mid-shell region
Han-Kui Wang (School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China, Department of Physics, Zhejiang SCI-TECH University, Hangzhou, China); H. Yang (Department of Physics, Zhejiang SCI-TECH University, Hangzhou, China); M.L. Liu (Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China); Y.B. Wang (China Institute of Atomic Energy, P.O. Box 275(10), Beijing, China)
; B. Jiang (School of Physics, Xi'an Jiaotong University, Xi'an, China); et al - Show all 6 authors
This study analyzes the evolution of single-proton states within the odd-A isotopes of $^{117−133}$Sb. We identified the monopole force interaction between the and orbitals as the key driver of the ground-state inversion observed in $^{121}$Sb. Moreover, we provide an additional asset for this monopole force by investigating the negative-parity states in $^{132}$Sb and demonstrating its manifestation through a comparative assessment of πg-νh multiplets. Our results provide conclusive evidence, for the first time, explaining the ground-state inversion in $^{121}$Sb through observations in $^{132}$Sb. The increasing occupation and configurations of the orbit revealed that the single-proton property of state 5/2$^{+}$ remained robust even in the neutron mid-shell region.
