Repulsive three-body force and channel-coupling effects via ~(12)C + ~(12)C scattering at 100A MeV

摘要

The angular distributions of differential cross sections of ~(12)C + ~(12)C elastic and inelastic scattering populating the ground and excited states in ~(12)C up to 15 MeV excitation energy are precisely measured for the first time at an incident energy of 100A MeV to study the effect of repulsive three-body forces. Using the high-resolution spectrometer Grand Raiden at the Research Center for Nuclear Physics (RCNP), Osaka University, we have obtained the differential cross sections for the ground state (0_1~+) and 4.44 MeV (2_1~+) excited state, as well as the summed differential cross sections for the states between 4.44 and 15 MeV in the angular range of 1.0°–7.5°. The results are compared with microscopic coupled-channel calculations. The potential between the colliding nuclei is determined by the double folding method with three different complex G-matrix interactions, the ESC, CEG07b, and Mpa interactions. The CEG07b and MPa interactions, which include repulsive three-body forces, describe the data well, whereas the ESC interaction, which does not include repulsive three-body forces, fails to reproduce the data. The results provide evidence of repulsive three-body forces in ~(12)C and demonstrate the possible sensitivity of elastic scattering to three-body forces.