The rise of the cross section and the Mandelstam diagrams

Abstract We evaluate multi-pomeron exchanges based on non-planar, Mandelstam-like diagrams of an underlying field theory. We take into account both the coupling of many pomerons to the external lines and the coupling of the pomerons among themselves in a scheme that can incorporate low-energy effects in a natural way. We express the total cross section in terms of one-two-three-pomeron exchange plus a term due to the triple-pomeron interaction. We have considered two possible values for the intercept: α 0 = 1.025, α 0 = 1. In both cases we can find agreement with the observed rise of the pp total cross section.