NONLOCAL EFFECTS IN A SEMICLASSICAL WKB APPROACH TO SUBBARRIER NUCLEAR-FUSION PROCESSES

We have shown that the large enhancement of sub-barrier fusion cross s ections for heavy-ion collision processes can be partially accounted f or by using the variation of the effective mass due to nonlocal effect s in WKB theory. Although reasonable;agreement of our predicted result s for the fusion cross sections and average angular momenta with the o bserved experimental data for several systems have been observed, it i s evident that the nonlocal effects alone cannot explain the entire en hancement as claimed by Galetti et al. [Phys. Rev. C 50, 2136 (1994)]. It is then suggested that nonlocality needs to be supplemented by nuc lear deformation and other degrees of freedom.