The analog ($p$, ${}_{}{}^3{}_{}{}^{}\mathrm{He}$) and ($p, t$) reactions on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ have been compared at 27.0 MeV incident proton energy. In contrast to previous results at higher energies (≥43.7 MeV), the intensity ratio predicted by isospin conservation was satisfied only at small angles.

• Received 5 April 1973

DOI:https://doi.org/10.1103/PhysRevLett.31.605