Quasielastic transfer in the {sup 136}Xe+{sup 64}Ni reaction

Single and multinucleon transfer yields for the {sup 136}Xe+{sup 64}Ni reaction at a scattering energy {approx}5{percent} above the Coulomb barrier energy are studied using particle{endash}{gamma}-ray coincidence data. Q-value and scattering-angle distributions are extracted for the stronger channels. A fast transfer mechanism dominates the yields to these channels over an extended Q-value range, leading to a concentration of the cross section near the grazing angle. Analysis of the angular distributions based on a semiclassical barrier penetration model suggests that the single-nucleon and two-neutron exchange channels are dominated, respectively, by direct and two-step sequential transfer from the ground or low-lying excited states of the participating nuclei. The multiproton transfer channels have angular distributions that indicate a more complex mechanism, although direct cluster transfer from an excited configuration cannot be fully discounted. In a separate analysis, the relative population of different mass channels is found to be in general agreement with the expectations of a {open_quotes}random walk{close_quotes} model of particle exchange. {copyright} {ital 1997} {ital The American Physical Society}