Further monopole effects in neutron-rich Sb isotopes

The level spectra of neutron-rich Sb isotopes have been investigated within a shell-model space containing cross-shell excitations and the intruder orbit i(13/2). High-spin levels (27/2(-)) and (29/2(-)) in Sb-135 are taken over by the monopole effect induced by orbit i(13/2). The ground state and excited levels in Sb-136 are well improved by considering the monopole correction between neutron orbits f(7/2 )and h(9/2). The energy shrinking of the first excited state 5/2(+) in Sb-135,Sb-137 isotopes is explained by the pi d(5/2) shift due to the attractive pi d(5/2)nu f(7/2 )monopole interaction when increasingly more neutrons occupy orbit f(7/2). The ground state of Sb-139 is predicted as 5/2(+ )owing to the shrinking of the 5/2(+ )states in Sb isotopes that causes ground state inversion when N = 88. Further monopole effects extend the applicable range of the present Hamiltonian to nuclei with more neutrons above the N = 82 shell. This Hamiltonian will be public, and researchers are encouraged to contact the authors.