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

A fast rotating Cr-48 is predicted to be highly prolate and deformed after a Jacobi shape transition and just before fission. In this article, it is proposed that an arrow and high spin Mg-24+Mg-24 resonance corresponds to the formation of this exotic Cr-48. Moreover the Mg-24+Mg-24 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 Cr-48, 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 gamma array CLARA, and, for the fusion-evaporation channels, the Si array EUCLIDES and the gamma array GASP. Strong resonant effects have been observed in the inelastic channels involving the 2(+) and 4(+) states of the Mg-24 ground state (g.s.) band. Weaker effects are also seen in certain fusion-evaporation channels. Both results will be discussed here.