Study of intruder band in 112Sn Original Research Article

Excited states of the positive-parity intruder band in 112Sn, populated in the 100Mo(20Ne, α4n) reaction at a beam energy of 136 MeV, have been studied. The band has been observed up to 11570.0 keV with spin (24+). Mean lifetimes have been measured for six states up to the 22+, 10335.1 keV level and an upper limit of the lifetime has been estimated for the 11570.0 keV (24+) state. The B(E2) values, derived from the present lifetime results, correspond to a moderate quadrupole deformation of β2∼0.18 for states with spin Jπ⩾12+, and the decrease in B(E2) for the 14+→12+ transition is consistent with a ν2(h11/2) alignment at ℏω∼0.35 MeV, predicted by a cranked shell-model calculation. Total Routhian surface calculations predict a triaxial shape following the alignment.