Mechanisms of the reaction pi(-)p->a(0)(0)(980)n->pi(0)eta n at high energies

The main dynamical mechanisms of the reaction pi(-)p --> a(0)(0)(980)n --> pi(0) eta n high energies, currently investigated at Serpukhov and Brookhaven, are considered in detail. It is shown that the observed forward peak in its differential cross section can be explained within the framework of the Regge pole model only by the conspiring rho(2) Regge pole exchange. The tentative estimates of the absolute pi(-)p --> a(0)(0)(980)n --> pi(0) eta n reaction cross section at P-lab(pi) = 18 GeV/c are obtained: sigma approximate to 200 nb and, in the forward direction, d sigma/dt approximate to 940 nb/GeV2. The contribution of the one pion exchange, which is forbidden by G parity and which can arise owing to the f(0)(0)(980) - a(0)(0)(980) mixing, is also estimated. The role of the Regge cuts in the nonflip helicity amplitude is briefly examined and the conclusion is made that the contributions of the cuts have to be inessential in comparison with the conspiring rho(2) Regge pole exchange.