Determination of smallxshadowing corrections at DESY HERA

Abstract

The recent F 2 data can be described using the DGLAP evolution equations with an appropriate choice of input distributions and the choice of the starting scale for the Q 2 evolution. We demonstrate in this paper that we cannot conclude that there are no significant shadowing corrections at HERA kinematic region using F 2 data only. In this paper we calculate the shadowing corrections to the longitudinal structure function F L (x, Q 2 ) and to the charm component of the proton structure function F c 2 (x, Q 2 ) at the HERA kinematic region using an eikonal approach. We demonstrate that the shadowing corrections to these observables are very large and that the charm production is strongly modified at small-x. Our results agree with the recent few H1 data.12.38.Aw; 12.38.Bx; 13.90.+iTypeset using REVT E X †

NNLO solution of nonlinear GLR–MQ evolution equation to determine gluon distribution function using Regge like ansatz

“…This equation deals with a new quantity G 2 (x, Q 2 ) interpreted as the two gluon distribution function per unit area of the hadron. In addition to the explanation of gluon saturation phenomena, GLR-MQ equation predicts a critical line which supposed to separate the gluon saturation regime and the perturbative regime valid in this critical line border [14]. Most significantly GLR-MQ equation introduces a characteristic momentum scale Q 2 s which provides the measure of the density of the saturated gluons.…”

“…The GLR-MQ equation is regarded as a hypothetical link between perturbative and non perturbative region. There has been some work in recent years inspired by GLR-MQ approach [14,15]. The solution of GLR-MQ equation provides the determination of the saturation momentum that incorporates physics in addition to that of the linear evolution equations commonly used to fit DIS data.…”

Geometrical scaling in charm structure function ratios

“…, where M N is the nucleon mass, charm production can occur well below the Q 2 threshold, Q 2 ≈4m 2 c , at small x [6].…”

A phenomenological analysis of the longitudinal structure function at small x and low Q 2

“…Therefore, new dynamical non-linear QCD effects associated to the unitarity corrections are expected to slow down its further growth [1,2,3,4,5,6,7]. The search of signatures for these effects has been an active subject of research in the last years [8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24].…”

“…The dipole hadron cross section σ dip contains all information about the target and the strong interaction physics. There are several phenomenological implementations for this quantity [9,10,11,12,19,21]. The main feature of these approaches is to be able to match the soft (low Q 2 ) and hard (large Q 2 ) regimes in an unified way.…”