Unraveling the reaction mechanism for large alpha production and incomplete fusion in reactions involving weakly bound stable nuclei
S. K. Pandit, A. Shrivastava, K. Mahata, N. Keeley, V. V. Parkar, R. Palit, P. C. Rout, K. Ramachandran, Ashok Kumar, S. Bhattacharyya, V. Nanal, S. Biswas, S. Saha, J. Sethi, P. Singh, S. Kailas
Abstract
The origin of the large α particle production and incomplete fusion in reactions involving weakly-bound α+x cluster nuclei still remains unresolved. While the (two-step) process of breakup followed by capture of the “free” complementary fragment (x) is widely believed to be responsible, a few recent studies suggest the dominant role of (direct) cluster stripping. To achieve an unambiguous experimental discrimination between these two processes, a coincidence measurement between the outgoing α particles and γ rays from the heavy residues has been performed for the 7Li(α+triton)+93Nb system. Proper choice of kinematical conditions allowed for the first time a significant population of the region accessible only to the direct triton stripping process and not to breakup followed by the capture of the “free” triton (from the three-body continuum). This result, also supported by a cluster-transfer calculation, clearly establishes the dominance of the direct cluster-stripping mechanism in the large alpha production.