Compound-nucleus contributions to 6Li+12C scattering.

Abstract

Statistical compound-nucleus contributions to enhanced back-angle cross sections for $^{6}\mathrm{Li}$ + $^{12}\mathrm{C}$ elastic scattering and for inelastic scattering to the channels, $^{6}\mathrm{Li}$(${3}^{+}$, 2.18 MeV) + $^{12}\mathrm{C}$(g.s.) and $^{6}\mathrm{Li}$(g.s.) + $^{12}\mathrm{C}$(${2}^{+}$, 4.44 MeV), are studied. Differential cross sections and vector analyzing powers in the range ${\mathrm{\ensuremath{\Theta}}}_{\mathrm{c}.\mathrm{m}.}$\ensuremath{\approxeq}130\ifmmode^\circ\else\textdegree\fi{}--165\ifmmode^\circ\else\textdegree\fi{} have been measured at ${\mathit{E}}_{\mathrm{c}.\mathrm{m}.}$ = 20 MeV by detecting recoil $^{12}\mathrm{C}$ nuclei from $^{6}\ensuremath{\rightarrow}$ elastic scattering and inelastic scattering to the $^{6}\mathrm{Li}$(${3}^{+}$, 2.18 MeV) state. Adding a statistical compound-nucleus contribution is shown in general to reduce the magnitude, and to leave unaffected the sign, of theoretical calculations of vector analyzing powers. Analysis, including Hauser-Feshbach calculations, of the above data along with previous data indicates that compound-nucleus contributions are unimportant in the elastic and inelastic $^{6}\mathrm{Li}$(2.18 MeV) scattering channels, and are insufficient to resolve discrepancies between current coupled-channels calculations and large-angle data for inelastic $^{12}\mathrm{C}$(4.44 MeV) scattering. \textcopyright{} 1996 The American Physical Society.