INSTANTON-LIKE TRANSITIONS IN HIGH-ENERGY COLLISIONS

In the framework of a systematic approach, the present status of the p roblem of instanton-like transitions in high energy particle collision s is reviewed. The arguments in favor of the exponential form of the t otal two-particle cross section in the one-instanton sector, exp[1/g2F (E/E(sph))], are summarized. The perturbative technique for the evalua tion of the function F(E/E(sph)) is considered in detail. The nonpertu rbative semiclassical approach to the evaluation of F(E/E(sph)), which may provide a reasonable basis for the numerical study of the problem , is discussed.