High-spin excitations of $^{84}_{35}Br_{49}$ and $^{85}_{35}Br_{50}$: Mapping the proton sub-shells towards $^{78}$Ni

The Br-84,Br-85 nuclei have been produced as fission fragments in the fusion reaction O-18+Pb-208 at 85 MeV bombarding energy and studied with the Euroball IV array. The high-spin states of the odd-odd Br-84 nucleus have been identified for the first time, the observed structure being built on the known 6(-) isomeric state. High-spin states of Br-85 have been observed up to 5.4 MeV excitation energy and spin I similar to 21/2. From angular correlation analysis, spin values have been assigned to most of the Br-85 excited states up to 4 MeV. None of these excited states has been found to exhibit a delayed decay having T-1/2 > 10ns. All the observed states in Br-84,Br-85 can be described by various proton excitations involving at least the two sub-shells (pi f(5/2) and pi p(3/2)) located just above the Z = 28 shell closure