Evidence for multistep processes in proton capture reactions.

Abstract

Proton capture populating the ${(7/2)}^{\mathrm{\ensuremath{-}}}$ second-excited state in $^{7}\mathrm{Be}$, at an excitation energy of 4.57 MeV, is reported for the $^{6}(\mathit{p}$,\ensuremath{\gamma}${)\mathrm{}}^{7}$Be reaction at a bombarding energy of 44.4 MeV. This state cannot be populated by either a conventional direct or semidirect process. Evidence is presented showing that this state could be populated via a multistep excitation in the entrance channel.