Elastic and inelastic scattering of12C+12C atE/A≥10MeV and the deformation parameters

Elastic and inelastic scattering of ${}_{}{}^{12}{}_{}{}^{}$C${+\mathrm{}}^{12}$C, especially excitations of the ground-rotational-band members in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, have been studied at 139.5 and 158.8 MeV. Although reasonable fits to the angular distributions for the band members were obtained with a shallow optical potential, rainbowlike gross bumps observed at large angles in the elastic scattering were not explained at all by coupled-channel calculations for the rotational band. The present results of ‖${\beta }_2$R‖ and ‖${\beta }_4$R‖ obtained by the coupled-channel calculations are in good agreement with previously reported results, except some from ${}_{}{}^{12}{}_{}{}^{}$C${+\mathrm{}}^{12}$C scattering. These analyses indicate a significant difference in the deformation lengths derived depending upon the signs of the deformations. The sign of the deformation parameters is also discussed.