Evolution of the $\pi g_{9/2} \nu h_{11/2}^{2}$ multiplet in the neutron-rich 49 In isotopes: Evidence for the gradual filling of the neutron sub-shell

Abstract

High-spin states from the three-quasiparticle (3qp) configuration $\pi$ g $_{9/2}\nu$ h11/2 2 in the neutron-rich 49In isotopes have been studied in the framework of shell model calculation. The two-body residual interactions needed for such calculations have been extracted from the level schemes of neighbouring nuclei. In particular, the evolution of the proton-neutron $\pi g_{9/2}\nu h_{11/2}$ interaction has been analyzed as a function of the neutron number. When the gradual filling of the $\nu h_{11/2}$ sub-shell is taken into account, the results of the 3qp configuration calculations are found to be very close to the experimental positive-parity yrast states located above 2 MeV excitation energy in $^{113\mbox{--}121}$ In. Moreover, several long-lived isomeric states with positive parity are predicted in 123,125,127In.