The ${\mathrm{O}}^{16}(d, \alpha ){\mathrm{N}}^{14}$ reaction has been observed to proceed to the first excited state of ${\mathrm{N}}^{14}$ in violation of the isotopic-spin selection rule. The yields of this alpha group and the alpha groups leading to the ground state and second excited state have been measured from 5.5- to 7.5-Mev bombarding energy. At 7.03 Mev, the angular distributions of the three groups have been measured from 15 to 130 degrees. An absolute cross section has been obtained by comparison with the known proton elastic scattering from ${\mathrm{O}}^{16}$. The observed isotopic-spin selection rule violation is of the order of magnitude predicted by theory on the basis of Coulomb-force mixing of states of different isotopic spin.

• Received 11 September 1956

DOI:https://doi.org/10.1103/PhysRev.104.1598