Nucleon-Nucleon Correlations in Heavy Ion Transfer Reactions: Recent Investigations at Energies Far Below the Coulomb Barrier

摘要

Excitation functions of one- and two-neutron transfer channels have been measured for the ~(96)Zr+~(40)Ca and ~(116)Sn+~(60)Ni systems at bombarding energies ranging from the Coulomb barrier to ~ 25% below. Target-like recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental transfer probabilities have been compared, in absolute values and in slope, with semiclassical microscopic calculations which incorporate nucleon-nucleon pairing correlations. For the first time in a heavy ion collision, one was able to provide a consistent description of one and two neutron transfer reactions by incorporating, in the reaction mechanism, all known structure information of entrance and exit channels nuclei. In particular, there is no need to introduce any enhancement factor for the description of two neutron transfer, of course very important are the correlations induced by the pairing interaction.