We measured the analyzing power for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$($\overrightarrow{p}$,$n$)${}_{}{}^{16}{}_{}{}^{}\mathrm{F}$ ($4^{-}$,6.37 MeV) reaction at 134.0 MeV and the differential cross section for the same reaction at 135.2 MeV. The shape of the cross section for the transition to this unnatural parity stretched state is described well by a distorted-wave impulse-approximation calculation using a ${(\pi d_{\frac{5}{2}},\nu {p_{\frac{3}{2}}}^{-1\mathrm{}})}_{4^{-}}$ configuration and the effective interaction derived by Love and Franey from nucleon-nucleon phase shifts. The analyzing power from this calculation reproduces all of the qualitative features of the data and supports the use of the impulse approximation as an excellent starting point for describing the reaction mechanism. Quantitative agreement between the experimental and theoretical analyzing power can be improved by eliminating the imaginary tensor term of this interaction and taking the real part to be that derived by Love from the Sussex matrix elements. The sensitivity of the calculations to the choice of optical potentials and the importance of spin-orbit distortion is explored.

NUCLEAR REACTIONS ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$($\overrightarrow{p}$,$n$)${}_{}{}^{16}{}_{}{}^{}\mathrm{F}$, $E=134\mathrm{}$ MeV; measured neutron spectra at 12 angles between $\theta =0\mathrm{}° \mathrm{and} 62.9°$; extracted $\sigma \left(\theta \right)$ and $A\left(\theta \right)$ to $J^{\pi }=4^{-},6.37\mathrm{}$ MeV state of ${}_{}{}^{16}{}_{}{}^{}\mathrm{F}$. Compared angular distributions of $\sigma \left(\theta \right)$ and $A\left(\theta \right)$ with calculations based on a nucleon-nucleon effective interaction.

• Received 13 October 1981

DOI:https://doi.org/10.1103/PhysRevC.25.1715