Wide-angle measurement of 48 MeV 6Li projectile fragmentation on 197Au

The 6Li →α+d projectile breakup at E(6Li)=48 MeV with a 197Au target is studied at large relative fragment energies. Both inclusive and exclusive measurements are carried out. The peaks corresponding to the protons and α-particles appear near the expected beam velocity positions while the deuterons and tritons are shifted to lower energy values. Calculations in the framework of both prior- and post-form distorted-wave Born approximation theories delineate an oscillatory structure for the exclusive cross section at larger α-d separation angles in consonance with the data profile. The oscillation is found to be a result of delicate Coulomb and nuclear interference. The distorted-wave analysis of the existing data at E(6Li)=75 MeV, where the Coulomb effect is smaller, show a different feature altogether having no oscillation at larger angles. At larger angles, the factorisation theory for uncorrelated events seems to hold better at 75 MeV incident energy than at 48 MeV. The implications of these results are discussed. (orig.)