Cross sections for elastic scattering and quasielastic transfer have been measured for ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$${+}^{96,100}$Mo at ${\mathit{E}}_{\mathrm{lab}}$=180 MeV (∼60% above the Coulomb barrier). The transfer yields are dominated by the ${(}^{32}$S, ${}_{}{}^{33}{}_{}{}^{}\mathrm{S}$) and ${(}^{32}$S, ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$) reactions which account for about 50% of the total quasielastic transfer strength. The transfer probabilities show an exponential decrease with increasing distance of closest approach. The measured decay constants are smaller than the binding-energy derived decay constants. The observed enhancements of the transfer probabilities for the simplest single-step transfer reactions (involving the transfer of up to two nucleons) can be understood quantitatively in terms of quantum diffraction.

• Received 14 November 1994

DOI:https://doi.org/10.1103/PhysRevC.52.744