Triple-differential cross sections to discrete states in the /sup 16/O(. pi. /sup +/,2p)/sup 14/N reaction

The /sup 16/O(..pi../sup +/,2p)/sup 14/N reaction has been studied at T/sub ..pi../ = 59.6 MeV. Good energy resolution of 1 to 2 MeV allows several states in /sup 14/N to be resolved. Triple-differential cross sections are presented for the transitions to the /sup 14/N 1/sup +/ ground state and 1/sup +/ 4 MeV state. The quasideuteron model is used to construct a T matrix for each transition. A fit to the data requires an additional term in the T matrix giving a large anisotropy in the angular distribution of the /sup 14/N recoil momentum vector. The ground state T matrix has an unexpected enhancement near zero recoil momentum of the /sup 14/N nucleus. The ''measured'' T matrices are then used to extrapolate to unmeasured regions of phase space giving double differential, single-differential, and total cross sections for each transition.