Experimental study of the ${}^{11}\text{B}(p,3\alpha )\gamma$ reaction at $E_p=0.5-2.7$ MeV

Abstract

Our understanding of the low-lying resonance structure in ${}^{12}$C remains incomplete. We have used the ${}^{11}\text{B}(p,3\alpha )\gamma$ reaction at proton energies of $E_p=0.5-2.7$ MeV as a selective probe of the excitation region above the $3\alpha$ threshold in ${}^{12}$C. Transitions to individual levels in ${}^{12}$C were identified by measuring the 3$\alpha$ final state with a compact array of charged-particle detectors. Previously identified transitions to narrow levels were confirmed and new transitions to broader levels were observed for the first time. Here, we report cross sections, deduce partial $\gamma$-decay widths and discuss the relative importance of direct and resonant capture mechanisms.

9 pages, 7 figures, 5 tables; added details on data analysis

References in corpus (1)

• Unbound states in ${}^{12}$C populated by $\gamma$-decay of the $(J^{\pi },T)=(2^{+},1)$ 16.11 MeV state