New data on the isospin-forbidden reaction ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}(d, {\alpha }_2){}_{}{}^{10}{}_{}{}^{}\mathrm{B}\mathrm{}\left(1.74\right)\mathrm{}$ disagree with Noble's proposed direct reaction via a $2^{+}$ doublet in ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$. In contrast to other studies, we find no convincing evidence that direct reactions contribute a major portion of the large isospin-forbidden cross sections.

• Received 3 November 1969

DOI:https://doi.org/10.1103/PhysRevLett.23.1409