Isomer spectroscopy of 127Cd

The spin and configurational structure of excited states of Cd-127, the two-proton and three-neutron hole neighbor of Sn-132, has been studied. An isomeric state with a half-life of 17.5(3) mu s was populated in the fragmentation of a Xe-136 beam on a Be-9 target at a beam energy of 750 MeV/u. Time distributions of the delayed gamma transitions and gamma gamma coincidence relations were exploited to construct a decay scheme. The observed yrast (19/2)(+) isomer is proposed to have dominant configurations of nu(h(11/2)(-3))pi(g(9/2)(-1), p(1/2)(-1)), nu(h(11/2)(-2)d(3/2)(-1))pi(g(9/2)(-2)), and nu(h(11/2)(-2), s(1/2)(-1))pi(g(9/2)(-2)) and to decay by two competing stretched M2 and E3 transitions. Experimental results are compared with the isotone Sn-129. The new information provides input for the proton-neutron interaction and the evolution of neutron hole energies in nuclei around the doubly magic Sn-132 core.