The Strong Role of N/Z Degree of Freedom in Ca + Ca Reactions at 25 MeV/Nucleon

Isospin effects on dynamics of semi-central collisions involving 40Ca + 40Ca, 40Ca + 48Ca and 48Ca + 48Ca reactions at 25 MeV/nucleon have been investigated. For the selected class of events, the balance between the emission of evaporation residues and the presence of binary-like phenomena seems to be influenced by the neutron to proton ratio (N/Z) of entrance channels. In particular, for neutron-rich systems, evaporation residue emission is enhanced. Experimental observations confirm the key role played by the N/Z degree of freedom on nuclear dynamics at 25 MeV/nucleon. (authors)