Evidence of non-statistical structures in the elastic and inelastic scattering of 58Ni+58Ni and 58Ni+62Ni and intermediate dinuclear states

Excitation functions and angular distributions of 58Ni+58Ni and 58Ni+62Ni scattering at energies just above the Coulomb barrier have been measured around θcm=90 in energy steps ΔEcm=0.25 MeV from Ecm≅110 MeV to Ecm≅120 MeV for 58Ni+58Ni and from Ecm≅110 MeV to Ecm≅118 MeV for 58Ni+62Ni. Evidence for structure of non-statistical character has been found in the angle-summed excitation functions; this evidence is corroborated by the analysis of the angular distributions. This is the first time that non-statistical structure in elastic and inelastic scattering is reported with high confidence level for this mass and excitation energy ranges. Attempts are presented to understand the nature of this structure, including the presence of intermediate dinuclear states and virtual states in a potential well. (orig.)