Excitation of the giant resonance region in silicon by inelastic scattering of 115 MeV protons

Abstract

Differential cross sections for the excitation of the giant resonance region in silicon have been measured over the angular range 10\ifmmode^\circ\else\textdegree\fi{} to 34\ifmmode^\circ\else\textdegree\fi{} by inelastic scattering of 115 MeV protons. The giant resonance exhibits fine structure which is similar to that observed in ($\ensuremath{\alpha}$,${\ensuremath{\alpha}}^{\ensuremath{'}}$) and low-energy ($p$,${p}^{\ensuremath{'}}$) data. The angular distribution for the giant resonance has been analyzed in terms of the distorted-wave Born approximation and 19-26% of the energy weighted sum rule strength for $L=2$ has been identified. It is also found that the angular distribution for the excitation of the giant resonance region cannot be explained by assuming only the presence of giant quadrupole resonance.NUCLEAR REACTIONS Si($p$,${p}^{\ensuremath{'}}$), $E=115$ MeV; measured $\ensuremath{\sigma}(\ensuremath{\theta})$ for giant-resonance excitations and the low lying levels. Calculated energy-weighted sum rule strengths.