Breakup mechanisms in heavy-ion collisions at low energies

We investigate reaction mechanisms occurring in heavy-ion collisions at low energy (∼20 MeV/nucleon). In particular, we focus on the competition between fusion and breakup processes (deep inelastic and fragmentation) in semiperipheral collisions, where the formation of excited systems under various conditions of shape and angular momentum is observed. Adopting a Langevin treatment for the dynamical evolution of the system configuration, described in terms of shape observables such as quadrupole and octupole moments, we derive fusion and fission probabilities, from which the corresponding fusion and breakup cross sections can finally be evaluated. The dependence of the results on shape, angular momentum, and excitation energy is discussed.