Excitation Energies and Spins of the Yrast Superdeformed Band in ^{191}Hg

The excitation energies and spins of the levels in the yrast superdeformed band of ${}^{191}$Hg have been determined from two single-step $\gamma$ transitions and the quasi-continuum spectrum connecting the superdeformed and normal-deformed states. The results are compared with those from theoretical mean-field calculations with different interactions. A discussion of pairing in superdeformed states is also included.