${}^{12}\mathrm{C}(\overrightarrow{p},d{\pi }^{+}{)}^{11}\mathrm{B}$ has been investigated in the quasifree region at energies of 370 and 500 MeV. For each energy, measurements were made at the four angle combinations of $({\theta }_{d,\mathrm{left}},{\theta }_{\pi ,\mathrm{right}})$ equal to (15°, 30°), (15°, 55°), (25°, 30°), and (25°, 55°). In addition to strong excitation of the g.s. ${3/2}^{-}$ state, the 2.12 MeV ${1/2}^{-}$ and 5.02 MeV ${3/2}^{-}$ states are also excited with appreciable strength. Furthermore, a broad continuum at an excitation energy of about 20 MeV, corresponding to the ${1s}_{1/2}$ hole state is prominently seen. The pion differential cross section distributions exhibit maxima when the recoil nucleus momenta are at a minimum. Analyzing powers were obtained over the range of pion energies investigated. Several measurements for the ${}^2\mathrm{H}(\overrightarrow{p},d{\pi }^{+})n$ reaction are also reported. The results are compared with plane-wave impulse approximation and distorted-wave impulse approximation calculations.

• Received 10 July 1997

DOI:https://doi.org/10.1103/PhysRevC.58.964