Isomer and in-beam spectroscopy of medium-spin states in ^91,92Zr

Abstract

Near-yrast states have been identified in the stable 91,92Zr isotopes using the fusion evaporation reaction 82Se( 13C,xn)95-xZr at an incident beam energy of 50 MeV. Gamma-ray spectroscopy of states above the reported τ = 6 μs, I π=212+ isomer in 91Zr are reported for the first time with consequences for stimulating new shell model calculations which incorporate either the breaking of the N=50 shell closure and/or the inclusion of the negative parity h11/2 neutron intruder orbital. © 2006 American Institute of Physics