Angular distributions for the ground-state ($\Delta J^r=1^{+}$) and 0.96-MeV ($\Delta J^{\pi }=2^{+}$) transitions in the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}\mathrm{}(p,n)\mathrm{}{}_{}{}^{12}{}_{}{}^{}\mathrm{N}$ reaction have been measured at incident energies of 120, 160, and 200 MeV. The measured values of the differential cross section align themselves into smooth curves independent of incident energy when converted into plane-wave cross section values and plotted versus momentum transfer. This information supports the hypothesis that the spinisospin term of the effective interaction is almost energy independent in this energy region. Microscopic distortedwave impulse approximation calculations are presented.

[NUCLEAR REACTIONS ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}\mathrm{}(p,n)\mathrm{}{}_{}{}^{12}{}_{}{}^{}\mathrm{N}$, $E=120,160,200\mathrm{}$ MeV; measured neutron spectra at several angles between $\theta =0^{\circ }$ and $\theta ={30}^{\circ }$; extracted $\sigma (E,\theta )$ to g.s. and 0.96-MeV states of ${}_{}{}^{12}{}_{}{}^{}\mathrm{N}$. Compared angular distributions with microscopic calculations. Deduced plane-wave cross sections versus momentum transfer.]

• Received 26 February 1981

DOI:https://doi.org/10.1103/PhysRevC.24.335