Three different rotational bands have been observed to high spin in ${}^{75}\mathrm{Rb}$ using Gammasphere. The structures are similar, but not identical to those found in the neighboring $T_z=1/2$ nucleus ${}^{73}\mathrm{Kr}$. Conventional total Routhian surface (TRS) calculations with $T=1$ pairing are able to reproduce the rotational bands in ${}^{75}\mathrm{Rb}$ with extreme accuracy, but they completely fail in reproducing the spectra and decay pattern of the negative parity bands in ${}^{73}\mathrm{Kr}$. Simple qualitative arguments are put forward to show that the decay pattern observed in the negative parity bands in ${}^{73}\mathrm{Kr}$ can be accounted for by means of $T=0$ pair correlations. To further corroborate this scenario, deformation, and pairing self-consistent TRS calculations, including schematic $T=1$ and $T=0$ pairing, are performed for the first time indicating the onset of dynamical $T=0$ pair-correlations at high angular momenta.

• Received 2 March 2007

DOI:https://doi.org/10.1103/PhysRevC.76.011301