Abstract:We study the value of shadowing corrections (SC) in HERA kinematic region in Glauber -Mueller approach. Since the Glauber -Mueller approach was proven in perturbative QCD in the double logarithmic approximation (DLA), we develop the DLA approach for deep inelastic structure function which takes into account the SC. Our estimates show small SC for F 2 in HERA kinematic region while they turn out to be sizable for the gluon structure function. We compare our estimates with those for gluon distribution in leading order (LO) and next to leading order (NLO) in the DGLAP evolution equations. *

We study the value of shadowing corrections (SC) in the HERA kinematic region in the Glauber-Mueller approach. Since the Glauber-Mueller approach was proven in perturbative quantum chromodynamics (QCD) in the double-logarithmic approximation (DLA), we develop the DLA approach for the deep inelastic structure function which takes into account the SC. Our estimates show small SC for F2 in the HERA kinematic region while they turn out to be sizable for the gluon structure function. We compare our estimates with those for gluon distribution in leading order (LO) and next to leading order (NLO) in the DGLAP evolution equations.

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 †

In this paper we propose an improvement of the EKS nuclear parton distributions for the small x region of high energy processes, where the perturbative high parton density effects cannot be disregarded. We analyze the behavior of the ratios xG A /xG N and F A 2 /F D 2 and verify that at small x they are strongly modified when compared to the EKS predictions. The implications of our results for the heavy ion collisions in RHIC and LHC are discussed.

In this paper we estimate the influence of the shadowing effect and initial state parton energy loss in the quarkonium production at HERA-B. We analyze the xF behavior of the effective exponent α(xF) and present a comparison with the preliminary HERA-B data for J/Ψ production. Moreover, we estimate the magnitude of these effects in the J/Ψ production at RHIC.