C12 states populated in B10+B10 reactions

Abstract

$^{10}\mathrm{B}+^{10}\mathrm{B}$ reactions are measured with 50 and 72 MeV beams. The large spin of both beam and target nuclei (${J}^{\ensuremath{\pi}}={3}^{+}$) is particularly suitable for the population of high spin states in the exit channels. Population and decay of different states in $^{12}\mathrm{C}$ are studied through sequential decay reactions. The $^{12}\mathrm{C}$ excitation energy spectrum obtained from the $^{10}\mathrm{B}(^{10}\mathrm{B},^{8}\mathrm{Be})$ reaction shows a number of both known and new states. In particular, a new state at ${E}_{x}=24.4\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ is observed to be strongly populated in the triple $\ensuremath{\alpha}$-particle coincidences. The rarely seen state at ${E}_{x}=30.3\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ is found to be strong in the $d+^{10}\mathrm{B}$ decay channel, reinforcing the previous suggestions that it has the exotic $2\ensuremath{\alpha}+2d$ molecular structure.