Nonlocal effects in a semiclassical WKB approach to sub-barrier nuclear fusion processes

We have shown that the large enhancement of sub-barrier fusion cross sections for heavy-ion collision processes can be partially accounted for by using the variation of the effective mass due to nonlocal effects in WKB theory. Although reasonable agreement of our predicted results for the fusion cross sections and average angular momenta with the observed experimental data for several systems have been observed, it is evident that the nonlocal effects alone cannot explain the entire enhancement as claimed by Galetti et al. [Phys. Rev. C 50, 2136 (1994)]. It is then suggested that nonlocality needs to be supplemented by nuclear deformation and other degrees of freedom. copyright 1996 The American Physical Society