Neutron pair and proton pair transfer reactions between identical cores in the sulfur region

Optical model and exact finite range distorted-wave Born approximation analyses were performed on neutron pair exchange between identical cores for {sup 32}S and {sup 34}S nuclei and on proton pair exchange between identical cores for {sup 30}Si and {sup 32}S. The extracted spectroscopic factors were compared with theoretical ones deduced from Hartree-Fock calculations on these pairs of nuclei. The enhancement of the experimental cross sections with respect to the theoretical ones strongly suggests evidence for a nuclear Josephson effect. {copyright} {ital 1996 The American Physical Society.}