Threshold 3He(γ,π+)3H

Realistic wave functions are used to calculate threshold π+ photoproduction from 3He in the impulse approximation. The effects of the D-state components, the Coulomb interaction in 3He, and the nuclear size on this cross section are investigated. In particular, it is argued that since realistic forces underbind and produce too large a radius, such model calculations should be expected to give (approximately 10 percent) too small a cross section. The resulting theoretical estimate is in reasonable agreement with experimental data