Shell-model influence in the rotational nucleus 86Mo.

Abstract

High-spin states in $^{86}\mathrm{Mo}$ were studied by means of the fusion evaporation reaction $^{58}\mathrm{Ni}$${(}^{32}$S,2p2n${)}^{86}$Mo at 135 MeV beam energy. Charged-particle-\ensuremath{\gamma}\ensuremath{\gamma} and -\ensuremath{\gamma}\ensuremath{\gamma}\ensuremath{\gamma} coincidences recorded with the early implementation of the GAMMASPHERE array and the MICROBALL charged-particle detection system were used to largely extend the level scheme of the ${\mathit{T}}_{\mathit{z}}$=1 nucleus $^{86}\mathrm{Mo}$ to a possible spin of I=24\ensuremath{\Elzxh} at 13 MeV excitation energy. The excitation scheme is compared to neighboring nuclei. There is evidence for enhanced shell-model influence in the 4 quasiparticle region (I=12--16 \ensuremath{\Elzxh}). The observed (\ensuremath{\pi}=+,\ensuremath{\alpha}=0) sequence at spin I\ensuremath{\ge}16\ensuremath{\Elzxh} appears to be associated with a triaxial collective rotational band. This interpretation is supported by calculations within the configuration-dependent shell-correction approach with the cranked Nilsson potential. \textcopyright{} 1996 The American Physical Society.