Charged particle decay from giant monopole resonance in 28Si.

Abstract

Proton and alpha decay from the giant resonance region of $^{28}\mathrm{Si}$ excited with a 129 MeV alpha particle beam has been measured in coincidence with inelastic alpha particles detected at 0\ifmmode^\circ\else\textdegree\fi{}. The angular correlation data show the presence of decay from both E0 and E2 giant resonances. The E0 giant resonance decays primarily through the ${\mathrm{\ensuremath{\alpha}}}_{0}$, ${\mathrm{\ensuremath{\alpha}}}_{1}$, ${\mathit{p}}_{0}$, and ${\mathit{p}}_{1,2}$ channels with the branching ratios 18\ifmmode\pm\else\textpm\fi{}6 %, 24\ifmmode\pm\else\textpm\fi{}8 %, 23\ifmmode\pm\else\textpm\fi{}9 %, and 18\ifmmode\pm\else\textpm\fi{}8 %, respectively. Substantial direct decay is observed.