A partial-wave analysis is presented for new data on the isospin-forbidden ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(d,{\alpha }_2){}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ reaction for $13.8<~E_d<~16$ MeV. Two levels with $J^{\pi }=5^{-}$ are found at $E_x=22.51\mathrm{} \mathrm{and} 23.36$ MeV with widths of 610 and 500 KeV, respectively (uncertainties are $\approx 100$ keV in all cases). The prominent asymmetry in the region is due to interference between these levels and the tails of lower-energy levels. Consequently, no direct or semidirect reaction mechanism is necessary to explain the yield. The levels found appear to constitute an isospin-mixed pair with $〈H_c〉>40\mathrm{}$ keV. The allowed ${\alpha }_{0,1,3}$, transitions were measured simultaneously.

[NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(d,\alpha )$, $E=13.8-17\mathrm{}$ MeV; measured $\sigma (E,\theta )$. $S$-matrix analysis, deduced ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ level parameters, isospin-mixed states, reaction mechanism.]

• Received 23 July 1973

DOI:https://doi.org/10.1103/PhysRevC.9.16