Deeply virtual Compton scattering and saturation approach

Abstract

We investigate the deeply virtual Compton scattering (DVCS) in the color dipole approach, implementing the dipole cross section through the saturation model, which interpolates successfully between soft and hard regimes. The imaginary and real part of the DVCS amplitude are obtained and the results are compared to the available data.

Deeply virtual compton scattering in color dipole formalism

“…Namely, σ DIS ∝ W 2λ and σ DVCS ∝ W 4λ . The mean value R 0.5 is consistent with its early theoretical estimates using the aligned jet model [10] and the color dipole saturation model [4].…”

“…These theoretical studies repro- duce satisfactorily the main features of DVCS data [3]. On the other hand, a simple and intuitive high energy formalism has recently been used to describe DVCS [4]. It is given by a color dipole picture, which allows extending in the studies of saturation physics at low virtualities of the incoming photon.…”

“…[17] and applied to describe the recent DVCS data [15,16]. The second theoretical approach [4,5] is given by the color dipole approach, where the basic building blocks are the photon wavefunctions and the dipole cross section. The non-forward kinematics is encoded by the wavefunctions whereas the off- diagonal effects can be built-in in the parameterizations for the dipole-target cross section.…”

“…In the color dipole approach, as referred before, the imaginary part of the DIS (or DVCS) amplitude at t = 0 is expressed in the simple way [4]. The non-forward kinematics for DVCS is encoded in the color dipole approach through the different weight coming from the photon wavefunctions in Eq.…”

“…In this contribution one summarizes the studies in Refs. [4,5], where one applies the successful saturation model [6] to the DVCS process. The model interpolates between the small and large dipole configurations and has its parameters obtained from an adjust to small x HERA data.…”