Pion scattering and absorption contributions to proton emission from pion-nucleus collisions at T/sub. pi. / = 50--295 MeV

Journal Article · Fri Jul 01 04:00:00 EDT 1983 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.28.304· OSTI ID:6044276

Kallne, J; Minehart, R C; Whitney, R R; Boudrie, R L; McClelland, J B; Stetz, A W

Proton spectra of /sup 3,4/He(..pi../sup + -/,p) and /sup 27/Al(..pi../sup + -/,p) have been measured at theta/sub p/ = 20/sup 0/ for T/sub ..pi../ = 50, 100, 150, 200, and 250 MeV, and at theta/sub p/ = 20/sup 0/ and 40/sup 0/ for T/sub ..pi../ = 295 MeV. A small contributor to these spectra is the exclusive pion absorption reaction for which the cross section of /sup 4/He(..pi../sup +/,p)/sup 3/He is reported. Major contributions are identified to come from quasifree ..pi..N..--> pi..p scattering and ..pi..NN..-->..Np absorption for which cross sections are also reported. The quasifree cross sections are compared with those of the free reactions ..pi..N..--> pi..p and ..pi..d..-->..pp. We use these results to assess the contribution of quasifree reactions to the total reaction cross section. The comparison of the quasifree ..pi..NN..-->..Np reaction relative to ..pi..d..-->..pp is discussed in terms of differences in the attenuation and the dynamics of the reactions. This information is of interest for the phenomenological interpretation of complex reactions such as the two-nucleon absorption model of /sup 3/He(..pi../sup -/, n)/sup 2/H, /sup 4/He(..pi../sup -/, n)/sup 3/H, and /sup 4/He(..pi../sup +/, p)/sup 3/He in which ..pi..d..-->..pp is assumed to be an elementary process. This experiment also provides information on the cross section of ..pi../sup -/pp..-->..pn from which we determine the dependence of pion absorption on the isospin of the initial NN state.

• Research Organization: The Smithsonian Astrophysical Observatory, Cambridge, Massachusetts 02138
• OSTI ID: 6044276
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 28:1; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM 27 TARGET
ANGULAR DISTRIBUTION
CAPTURE
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DIRECT REACTIONS
DISTRIBUTION
ENERGY RANGE
HADRON REACTIONS
HELIUM 3 TARGET
HELIUM 4 TARGET
MESON REACTIONS
MEV RANGE
MEV RANGE 10-100
MEV RANGE 100-1000
NUCLEAR REACTIONS
PION REACTIONS
QUASI-FREE REACTIONS
TARGETS