Angular correlation, spin alignment, and resonance behavior in12C+12Cinelastic scattering

Abstract

We have studied $\ensuremath{\alpha}{\ensuremath{-}}^{12}\mathrm{C}$ angular correlations for peaks observed in the ${}^{12}\mathrm{C}{[}^{12}\mathrm{C}{,}^{12}\mathrm{C}{(3}_{1}^{\ensuremath{-}}){]}^{12}\mathrm{C}{(0}_{1}^{+})$ inelastic-scattering excitation function in the energy range between ${E}_{\mathrm{c}.\mathrm{m}.}=25$ to 35 MeV. The excitation-function data for $\ensuremath{\alpha}$-particle angles that correspond to the population of specific magnetic substates in the excited, decaying ${}^{12}\mathrm{C}$ nucleus suggest that these peaks are associated with a preferentially aligned configuration. The angular-correlation data are consistent with spin assignments of ${J}^{\ensuremath{\pi}}{=16}^{+}$ and ${18}^{+}$ for the resonancelike structures observed at ${E}_{\mathrm{c}.\mathrm{m}.}=27.5 \mathrm{MeV}$ and 33.1 MeV, respectively. The observed alignment, and the deduced spin values are consistent with a dinuclear configuration for these peaks.