Alpha -transfer contribution to 9Be+13C elastic and inelastic scattering.

Abstract

Angular distributions for the $^{9}\mathrm{Be}$${+}^{13}$C elastic and inelastic scattering have been measured at a $^{9}\mathrm{Be}$ bombarding energy of 50.46 MeV over an angular range from 10\ifmmode^\circ\else\textdegree\fi{} to 170\ifmmode^\circ\else\textdegree\fi{} c.m. Besides the ground state of $^{13}\mathrm{C}$, the 3.68 MeV ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=3/${2}^{\mathrm{\ensuremath{-}}}$ and the 7.55 MeV ${\mathit{J}}^{\mathrm{\ensuremath{\pi}}}$=5/${2}^{\mathrm{\ensuremath{-}}}$ levels are strongly populated. The enhancement of the backward cross section is clear evidence that the process is dominated by the exchange of an \ensuremath{\alpha} particle between two identical $^{9}\mathrm{Be}$ cores. The experimental relative integrated cross sections are fairly well reproduced by distorted wave calculations using an \ensuremath{\alpha}-cluster form factor and the shell-model spectroscopic strengths of Kurath.