EXCITATION-FUNCTION FOR HE-4(PI(-2 2-NUCLEON ABSORPTION ACROSS THE DELTA-RESONANCE(), PP)H)

Angular distributions and total cross sections for the He-4(pi+, pp)H- 2 reaction have been measured with small relative uncertainties at inc ident energies of T(pi+) = 64, 87, 114, 162, 217, 278, and 327 MeV. Th e results strongly support the quasideuteron absorption model for pion absorption on two nucleons, which is found to contribute only almost- equal-to 50% to the total absorption cross section near the DELTA reso nance. All essential reaction channels of pion absorption near the DEL TA resonance on heavier nuclei seem to be present in He-4, but not in He-3. Any nuclear-density-related increase of pion absorption in He-4 relative to H-2 is <50% and no binding energy effect is found.