High energy physics in the color glass condensate approach

Abstract

This thesis presents studies of high energy scattering in the framework of Color Glass Condensate (CGC) approach. We discuss one of the main problems at high energy scattering which is to find the correct next-to-leading order (NLO) approximation for the nonlinear evolution. We develop the NLO corrections approach which allow to describe deep inelastic scattering cross section in agreement with the experimental HERA data. We propose to take into account the NLO corrections introducing, in the nonlinear Balitsky-Kovchegov (BK) evolution equation, the correct high energy asymptotic behavior of the scattering amplitude. The parameters of the suggested model were fixed via fit to experimental HERA data. We treat the theoretical problem of the Odderon contribution to the scattering amplitude.The experimental indication on existence of the Odderon, makes it one of the urgent problem of high energy QCD. We build a theoretical approach for the Odderon contribution which includes the analytical solution to the linear and nonlinear evolution equation. We also propose an approach to soft hadron-hadron scattering in the framework of high energy QCD. We introduce the new dressed soft Pomeron, based on the CGC approach, as a first theoretical approximation for the soft processes. The dressed Pomeron turns out to be close to the phenomenological Donnachie-Landshoff Pomeron which describes the experimental data quite well. We use our NLO/Saturation model to reproduce experimental observables of proton-proton collision. This result, makes our soft Pomeron approach a good starting point in applying the CGC theory to soft interaction process.