Effect of 3α-like states in 12C to 12C- 12C scattering

Abstract

The polarization potential arising from the excitation of 0 2 + (7.66 MeV), 2 2 + (10.3 MeV) and 3α breakup states in 12C are calculated using the transition densities to these states which are obtained by Kamimura in the 3α resonating-group method. Adding this to the microscopic optical potential of Faessler et al. in the nuclear matter approach, the elastic and inelastic cross sections for the 12C- 12C scattering at low ( E lab = 360 MeV) to intermediate ( E lab = 1016 MeV) energies are calculated including the 2 1 + (4.44 MeV) and 3 1 − (9.64 MeV) states in the coupled channel formalism. We found that at low energy the polarization potentials cure the overestimation of the cross section seen in the calculation of Faessler et al. and improve the agreement with the experimental data while at intermediate energy they affect little the cross section and do not spoil the agreement with the experimental data obtained without the polarization potential.