Clustering effects in Cr-48 composite nuclei produced via the Mg-24+Mg-24 reaction

摘要

The nuclear properties of Cr-48 composite alpha-like nuclei produced at 60 MeV of excitation energy via the Mg-24 + 24Mg reaction were investigated. This excitation energy corresponds to a resonance with a narrow width (170 keV) observed in the elastic and inelastic channels, which was interpreted as a highly deformed state. To gain insight on the deformation of this state exclusive measurements of light charged particles were carried out with 8 pi LP apparatus at Laboratori Nazionali di Legnaro and compared to statistical model predictions. The measured of alpha-particle energy spectra, alpha-evaporation residues, alpha-alpha, and alpha-alpha-alpha correlations indicate the limitation of the rotating liquid drop model in describing the nuclear shape of the compound nucleus along the decay cascade. To reproduce the full set of experimental data very elongated nuclear shapes had to be considered, with an axis ratio 3 : 1 at the resonance angular momentum. This large deformation is consistent with previous findings for alpha-like nuclei and with the predictions of the cranked cluster model.