QUASI-MOLECULAR RESONANCE

Abstract Fragment-fragment-γ triple coincident measurements of the 28 Si + 28 Si re-action at E lab. = 111.6 MeV carefully chosen to populate J = 38 + resonancehave been performed at the VIVITRON tandem facility by using EurogamPhase II γ-ray spectrometer. In the 28 Si + 28 Si exit-channel, the resonancebehavior of the 28 Si + 28 Si reaction at the beam energy is clearly confirmed.An unexpected spin disalignment has been observed in the measured angulardistributions in the elastic, inelastic, and mutual excitation channels. Thisdisalignment is found to be consistent with particle-γ angular correlations andsupported by the molecular model prediction of a “butterfly motion”. TheK π = 0 +3 band corresponding to the large prolate deformation of the 28 Si ismore intensely fed in the resonance region. The selective population of high-excited states are discussed within a statistical fusion-fission model. In the 32 S + 24 Mg exit-channel, the spectroscopic study of the 32 S, has revealed thecontribution of a new γ-ray transition 0