The 8.65- and 8.69-MeV states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ have been studied with the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ reaction, with a resolution of 9 keV (full width at half maximum). Comparison of absolute spectroscopic strengths for this reaction and for the ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}\mathrm{}(d,p)\mathrm{}{}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ reaction to the 9.19-MeV ($J^{\pi }={\frac{7}{2}}^{+}$) and 9.27-MeV ($J^{\pi }={\frac{5}{2}}^{+}$) states in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ shows unambiguously that the spin sequence in ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ is the same as in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. An additional outcome of the present experiment is a measurement of the width of the 8.69-MeV state: ${\Gamma }_{\mathrm{TOTAL}}=15\mathrm{}\pm 1$ keV. The natural width of the 8.65-MeV state is considerably less than the experimental resolution width of 9 keV.

• Received 19 September 1972

DOI:https://doi.org/10.1103/PhysRevC.7.136