Core excitation in 92 Mo up to high spin.

An in-beam gamma-ray spectroscopy study of the even–even nucleus 92Mo has been carried out using the 30Si + 65Cu, 18O + 80Se reactions at beam energies of 120 and 99 MeV, respectively. Angular distribution from the oriented state ratio (R ADO) and linear polarization (Δasym) measurements have fixed most of the tentatively assigned spin-parity of the high-energy levels. A large-scale shell-model calculation using the GWBXG interaction has been carried out to understand the configuration and structure of both positive and negative parity states up to the highest observed spin. The high-spin states primarily originate from the coupling of excited proton- and neutron-core structures in an almost stretched manner. The systematics of the energy required to form a neutron particle-hole pair excitation, ν g 9/2 → ν d 5/2, is discussed. The lifetimes of a few high-spin states have been measured using the Doppler shift attenuation method. Additionally, a qualitative argument is proposed to explain the comparatively strong E1 transition feeding the 7310.9 keV level. [ABSTRACT FROM AUTHOR]