Collective and Non-Collective States in 116Cd Studied via the Beta-Decays of 116Agm1,m2,gs

Abstract

We have re-investigated the beta decay of the three isomers of $^{116}$Ag at the Holifield Radioactive Ion Beam Facility (HRIBF). Through the use of half-life information, we have been able to construct individual decay schemes for each isomer, and correct what was a puzzling inconsistency with the published data, namely the beta feeding of 2$^+$ states by a 5$^+$ isomer. Our results indicate that the feeding of these levels arises from a 3$^+$ isomer in $^{116}$Ag. A total of 271 gamma-ray transitions (159 new) were assigned to 148 levels (94 new) from the beta-decay of $^{116m1,m2,gs}$Ag. Significant deviations are observed from expected U(5) symmetry in the 0$^+$ and 2$^+$ members of the previously assigned three-phonon quintuplet. Candidate states for the quadrupole-octupole quintuplet states and $pi$g$_{9/2}-pi$p$_{1/2}$, $pi$g$_{9/2}-pi$p$_{3/2}$, $nu$h$_{11/2}-nu$s$_{1/2}$, $nu$h$_{11/2}-nu$d$_{3/2}$, and $nu$h$_{11/2}-nu$d$_{5/2}$ broken pair states are assigned.