Isomer spectroscopy of Cd127

Abstract

The spin and configurational structure of excited states of Cd127, the two-proton and three-neutron hole neighbor of Sn132, has been studied. An isomeric state with a half-life of 17.5(3) μs was populated in the fragmentation of a Xe136 beam on a Be9 target at a beam energy of 750 MeV/u. Time distributions of the delayed γ transitions and γγ coincidence relations were exploited to construct a decay scheme. The observed yrast (19/2)+ isomer is proposed to have dominant configurations of ν(h11/2-3)π(g9/2-1,p1/2-1), ν(h11/2-2d3/2-1)π(g9/2-2), and ν(h11/2-2,s1/2-1)π(g9/2-2) and to decay by two competing stretched M2 and E3 transitions. Experimental results are compared with the isotone Sn129. The new information provides input for the proton-neutron interaction and the evolution of neutron hole energies in nuclei around the doubly magic Sn132 core. © 2010 The American Physical Society.