Semiclassical treatment of fusion processes in collisions of weakly bound nuclei

Abstract

We describe a semiclassical treatment of nuclear fusion reactions involving weakly bound nuclei. In this treatment, the projectile-target relative motion is approximated by a classical trajectory while the intrinsic dynamics is handled by time-dependent quantum mechanics. The complete fusion probabilities are approximated by products of two factors: A tunneling probability and the probability that the system is in its ground state at the strong absorption radius. We investigate the validity of the method in a schematic two-channel application, where the continuum is represented by a single effective state with finite lifetime. Coupling effects below the Coulomb barrier are included through an analytical continuation of the time. Comparisons with full coupled-channels calculations are performed. The agreement between semiclassical and fully quantal calculations is quite good, suggesting that the procedure may be extended to more sophisticated discretizations of the continuum.