Description of inelastic processes in dual models ($B_5$ phenomenology)

A survey is presented of the application of the dual model to the description of inelastic scattering of hadrons $B_5$ phenomenology). The properties of a five-point dual amplitudes are considered for the scattering of scalar particles. These amplitudes are generalized first to include mesons, and then to include the case of meson-baryon scattering. A number of examples of the application of the model to reactions of the type MB$\to$MMB are considered (M and B stand for mesons and baryons, respectively). The predictions of the model are compared with experiment as well as with the predictions of earlier models. The advantages and shortcomings of $B_5$ phenomenology are discussed, particularly those connected with pion and vacuum exchange, and also with allowance for spin and unitarity. Further prospects for the development of the model, connected with its application to processes with larger multiplicity, and also connected with the use of a dual amplitude with Mandelstam analyticity, are considered. A table gives a complete summary of the results obtained by different workers within the framework of the $B_5$ phenomenology.