Band structure in 79 Y and the question of T50 pairing

Gamma rays in the N5Z11 nucleus 79 Y were identified using the reaction 28 Si( 54 Fe, p2n) 79 Ya t a2 00 MeV beam energy and an experimental setup consisting of an array of Ge detectors and the Recoil Mass Spectrometer at Oak Ridge National Laboratory. With the help of additional g-g coincidence data obtained with Gammasphere, these g rays were found to form a strongly coupled rotational band with rigid-rotor-like behavior. Results of conventional Nilsson-Strutinsky cranked shell model calculations, which predict a deformation of b 2;0.4, are in excellent agreement with the properties of this band. Similar calculations for the neighboring N5Z and N5Z11 nuclei are also in good agreement with experimental data. This suggests that the presence of the putative T50 neutron-proton pairing does not significantly affect such simple observables as the moments of inertia of these bands at low spins. @S0556-2813~98!50612-7#