α-clustering probabilities extracted from the 12C(α,2α)8Be reaction at 200 MeV
The energy-sharing distribution at a coplanar symmetric quasifree angle pair has been measured for the 12C(α,2α)8Be(g.s.) reaction at an incident energy of 200 MeV. The measured knockout cross sections are compared with distorted wave impulse approximation calculations. Extracted spectroscopic factors are found to be in reasonable agreement with a theoretical prediction and results from (p,pα) studies. The present results indicate a transition in the dynamics of this reaction in the incident energy region 140-200 MeV.