B(E1) stirengths and isospin symmetry in As-67 and Se-67

Abstract

In a recent experiment at Argonne National Laboratory, new spectroscopic information was obtained for the mirror pair As-67 and Se-67 via the measurement of the lifetime of analogue 9/2(+) excited states. The nuclei of interest were populated via the fusion evaporation reaction of S-32 on Ca-40, and selected by the combination of Gammasphere, Microball and the Neutron Wall arrays. The mirror B(E 1) strengths were measured via the centroid shift method in analogue E I transitions in 67As and 67Se. These findings are significant in determining the extent of conservation of isospin symmetry.