T=2states inC12andB12

Abstract

The ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,t){}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}(p,{}_{}{}^3{}_{}{}^{}\mathrm{He}){}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ reactions have been investigated at $E_p=54\mathrm{}$ MeV. The lowest $0^{+}$, $T=2\mathrm{}$ state in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ was identified at 27.57±0.03 MeV and a higher $T=2\mathrm{}$ state was found at 29.63±0.05 MeV. Their analogs in ${}_{}{}^{12}{}_{}{}^{}\mathrm{B}$ were found at 12.72±0.07 and 14.82±0.10 MeV, respectively. In a separate coincidence experiment, the proton and $\alpha$ decay modes of the $T=2\mathrm{}$ states in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ were studied. The 27.57 MeV state decays (30±10)% by proton emission and less than 10% by $\alpha$ emission. The 29.63 MeV state decays by about 80% proton emission and 20% $\alpha$ emission.