Pion Absorption Cross Section for ^2H and ^3He in the Delta-Isobar   Region: A Phenomenological Connection
  The absorption of \pi^+ on ^3He in the $\Delta$-region is evaluated with exact inclusion of the final state interaction among the three emerging protons. The absorption is described by a $\pi N \to \Delta$ vertex and a $N\Delta - NN$ transition t-matrix which are calculated from a phenomenological model for NN and \pi d reactions. In a calculation where the initial pion scattering effects are neglected, the predicted peaks of the pion absorption cross sections for ^2H and ^3He lie too high in energy in relation to the data. The effect of the final state three-nucleon interaction turns out to be too small for changing the magnitude and shifting the peak position of the total absorption cross section for ^3He. We demonstrate that the adjustment of the peak position for the deuteron cross section by small modifications of the $\Delta$-parameters, automatically leads to the correct peak position in ^3He. 
H. Kamada (1), M. P. Locher (1), T.-S. H. Lee (2), J. Golak (3), V. E.   Markushin (1), W. Gl\"ockle (4), H. Witala (3) ((1)...