EXPERIMENTAL RESULTS ON CHARGE-EXCHANGE REACTIONS WITH DELTA EXCITATIONS AND POLARIZATION STUDIES OF THE DELTA-RESONANCES AND N-ASTERISK(1440) RESONANCES

Main results of inclusive and exclusive experimental studies of (He-3, t), (t, He-3), (p, n), and (p, p') reactions on protons and nuclei wi th Delta excitation are discussed and summarized. New possibilities fo r investigation of coherent pion production are discussed. We point ou t that experiments at various energies with different projectiles offe r a possibility to separate partial contributions of mechanisms of cha rge-exchange reactions with excitation of broad baryonic resonances [D elta and N(1440)] in nuclei. The importance of interference effects i n this class of reactions is stressed. We discuss the (d, d') reaction on protons and nuclei, which gives a possibility to study polarizatio n effects in reactions with resonance excitations. Such information in the Delta, Roper and overlapping region, where interference between t hese resonances might be essential, can help much in understanding the ir properties and underlying mechanisms of the reactions considered. I t is particularly important for the theory of char,ae-exchange reactio ns at intermediate energies, which is unable at present to provide qua ntitative description of these reactions with nuclei.