Experimental determination of the excitation energy of superdeformed bands in 192,194Hg by analysis of the decay quasicontinuum γ rays -: art. no. 044316

Superdeformed bands in the mass A = 190 region decay suddenly, over a few states, at relatively low spin and high excitation energy. The decay path is very fragmented and only in a few cases have one-step or two-step decays been seen. Thus, only three superdeformed bands have so far been linked to the normal states they decay to. Most. of the gamma rays from the decay form an unresolved quasicontinuum spectrum. This paper describes the extraction of the total quasicontinuum decay spectrum that connects the superdeformed and normal yrast states. It also demonstrates that the excitation energy and spins of superdeformed bands can be determined by analyzing this total decay spectrum. The analysis method is first tested in Hg-194, which is one of the few cases where the excitation energy and spin of the yrast superdeformed band are known, and is then applied to the yrast superdeformed band in Hg-192, where no one-step decays have been seen thus far.