Inclusive cross sections for positive pion absorption leading to final States including two or more protons have been measured with a large solid angle detector for incident pion energies from 30 to 135 MeV for targets with A = 2-208. The mass dependences for the inclusive (π+,2p), (π+,3p), and total absorption cross sections for multiproton final states were found to be proportional to An with n ≈ 0.5. These cross sections also were observed to have an energy dependence at energies below 150 MeV reflective of the importance of the Δ(1232) resonance, similar to that observed for πd → >pp. The inclusive cross sections for (π+ ,4p) were found to be less than 10 mb for all targets at all energies. Estimates were also obtained for cross sections for pion absorption leading to 2p 1n and 3 p1n final states. Quasideuteron absorption contributions increase slowly with A, and the energy dependence of those contributions mirrors that for -π d→ pp. The data obtained here for multiproton final states indicate that a significant fraction of absorption events, increasing with A, most likely arises from final states containing fewer than two protons.
ASJC Scopus subject areas
- Nuclear and High Energy Physics