Evidence for Direct Triton Knockout in the He4(π,π't)p Reaction

Angular correlation functions for the He⁴(π^+/-,π^+/-'t)p reaction at the incident energy T_π=180 MeV and at four pion scattering angles have been measured. The He⁴(π^+/-,π^+/-'t)p data complement previous He⁴(π^+/-,π^+/-'p)t results by greatly extending the available range of proton emission angles. We calculate angular correlation functions of the cross sections with three different quasifree knockout models, and we show that direct triton knockout is crucial to an understanding of the data. © The American Physical Society