Constituent theory of large-mass production

It is argued that the study of the production of a pair of particles with large invariant mass can provide information on the dynamics of hadronic constituents in a similar way to the study of large-transverse momentum reactions. A general framework for the analysis and interpretation of these reactions is developed in terms of hadron-irreducible subprocesses and the constituent-interchange model. Counting rules are developed that predict the energy and mass dependence of the cross section. In particular, the production of a massive lepton pair or hadron pair in reactions with photon or hadron beams is discussed. A particularly interesting process that is discussed involves the production of a massive hadron pair in electron--positron annihilation. Its importance in measuring properties of generalized structure functions is emphasized