Average excited state lifetimes in /sup 73/Br

Lifetimes in the region of 10/sup -16/ s have been measured for excited states between 4 and 6.6 MeV in /sup 73/Br. The states were produced by the beta /sup +/(EC) decay of a mass-separated source of /sup 73/Kr, and they decayed by the emission of protons or gamma - rays; their lifetimes were measured by the particle X-ray coincidence technique. The data yield information on both gamma -ray and proton partial widths as well as on the level density, a level density parameter a=13.7 MeV/sup -1/ is obtained. With the level widths so determined, a statistical model calculation yields excellent agreement with the delayed proton spectrum if a smooth gaussian beta -strength function is employed. It is concluded, however, that without the lifetime data, beta -strength function information could not have been reliably extracted. (23 refs).