Pion Momentum Spectra in Nuclear Charge Exchange Reactions A(t, 3 He)

The charge exchange reaction (t, 3 He) on carbon and magnesium targets was investigated in experiments using a streamer chamber. The experimental longitudinal momentum spectrum for events with single secondary pion was compared with the calculated one. Only 60-70% of pions were shown may be produced by quasi-free Δ- excitation in the target nucleus. The momentum of the remaining pions was significantly higher than for delta pions and the coherent production in the projectile complementary to coherent production via N(1440) or/and N(1520) in the target nucleus was suggested. 24 refs., 3 figs., 1 tab