Fluctuations effects in high-energy evolution of QCD

Abstract

Recently, Iancu and Triantafyllopoulos have proposed a hierarchy of evolution equations in QCD at high energy which generalises previous approaches by including the effects of gluon number fluctuations and thus the pomeron loops. In this paper, we present the first numerical simulations of the Langevin equation which reproduces that hierarchy. This equation is formally the Balitsky-Kovchegov equation supplemented with a noise term accounting for the relevant fluctuations. In agreement with theoretical predictions, we find that the effects of the fluctuations is to reduce the saturation exponent and to induce geometric scaling violations at high energy.