Threshold Effects of Diffractive Production

It is proved in a quite general Feynman diagram model that the presence of diffractively produced inelastic channels at high energies leads to a decrease in the total cross section below as well as above the threshold for the process. A nondiffractive channel is shown to lead to the opposite effect, namely, the total cross section is increased at large energies. Asymptotically, the former behavior agrees with the results of the eikonal approach and the Gribov Reggeon calculus. On the basis of this theorem, one may expect to see a broad dip in the pp total cross section at intermediate energies if the triple Pomeron decouples.