Reinvestigation of the excited states in the proton emitter Lu151 : Particle-hole excitations across the N=Z=64 subshell

Abstract

The excited states of the proton emitter 151 Lu were reinvestigated in a recoil-decay tagging experiment at the Accelerator Laboratory of the University of Jyväskylä (JYFL). The level scheme built on the ground state of 151 Lu was updated with five new γ -ray transitions. Large-scale shell model calculations were carried out in the model space consisting of the neutron and proton orbitals 0g 7/2 , 1d 5/2 , 1d 3/2 , 2s 1/2 , and 0h 11/2 with the optimized monopole interaction in order to interpret the experimental level scheme of 151 Lu. It is found that the excitation energies of states above the 27/2 − and 23/2 + isomeric levels in 151 Lu can be sensitive to excitations from g 7/2 and d 5/2 to single-particle orbitals above N = Z = 64.