MOLECULAR RESONANCES AND THE JACOBI SHAPE TRANSITION: THE CASE OF 24Mg+24Mg AND 48Cr

Abstract

A fast rotating 48 Cr is predicted to be highly prolate and deformed after a Jacobi shape transition and just before fission. In this article, it is proposed that a narrow and high spin 24 Mg +24 Mg resonance corresponds to the formation of this exotic 48 Cr . Moreover the 24 Mg +24 Mg reaction has been studied at the Legnaro Tandem at a CM bombarding energy of 45.7 MeV, where a narrow and high spin resonance has been reported previously. To establish the connection between the resonance and a molecular state of 48 Cr , the decay of the resonance into the inelastic and fusion-evaporation channels has been investigated. The ON and OFF resonance decay yields have been measured using, for the inelastic channels, the fragment spectrometer PRISMA and the γ array CLARA, and, for the fusion-evaporation channels, the Si array EUCLIDES and the γ array GASP. Strong resonant effects have been observed in the inelastic channels involving the 2+ and 4+ states of the 24 Mg ground state (g.s.) band. Weaker effects are also seen in certain fusion-evaporation channels. Both results will be discussed here.