Search for cluster effects in p+12C elastic scattering by a diffractional method

We investigate medium-energy angular distribution data of proton elastic scattering on 12C, with the aim to probe the existence of cluster distributions in the ground state of 12C. In our approach, we exploit Coupled-channel calculations to describe the scattering from a spheroidal-like structure, and we include a further contribution, based on a diffraction scattering formula, to explicitly take into account a possible triangular α-cluster structure of the target. From the present analysis, we find a quite small cluster component in 12C ground state (with an upper limit on the occurrence probability of 1%, 99.75% confidence level) and an inter-cluster distance of ≃3.9 fm. These values are compared with several theoretical predictions reported in the literature.