Eur. Phys. J. C (2011) 71: 1757
https://doi.org/10.1140/epjc/s10052-011-1757-4

Regular Article - Theoretical Physics

All-loop calculation of the Reggeon field theory amplitudes via stochastic model

¹ Department of Physics, University of Oslo, PB1048 Blindern, 0316, Oslo, Norway
² Institute of Theoretical and Experimental Physics, 117259, Moscow, Russia
³ Department of High Energy Physics, Saint-Petersburg State University, Ulyanovskaya 1, 198504, Saint-Petersburg, Russia

^* e-mail: rodion.kolevatov@fys.uio.no

Received: 18 May 2011
Revised: 11 August 2011
Published online: 28 September 2011

Abstract

The evolution equations for Green functions of the Reggeon Field Theory (RFT) are equivalent to those of the inclusive distributions for the reaction–diffusion system of classical particles. We use this equivalence to obtain numerically Green functions and amplitudes of the RFT with all loop contributions included. The numerical realization of the approach is described and some important applications including total and elastic proton–proton cross sections are studied. It is shown that the loop diagram contribution is essential but can be imitated in the eikonal cross section description by changing the Pomeron intercept. A role of the quartic Pomeron coupling which is an inherent part of the stochastic model is shown to be negligible for available energies.