Parton densities in a nucleon

Abstract

In this paper we re-analyse the situation with the shadowing corrections (SC) in QCD for the proton deep inelastic structure functions. We reconsider the Glauber -Mueller approach for the SC in deep inelastic scattering (DIS) and suggest a new nonlinear evolution equation. We argue that this equation solves the problem of the SC in the wide kinematic region where α S κ = α S 3πα S

Solution to the evolution equation for high parton density QCD

“…It was also shown that the solution to the equation, suggested in Ref. [6], coincides with the solution to the GLR equation.…”

“…The first one was suggested as an obvious generalization of pQCD approach [6] while the second has been obtained from semiclassical gluon field approach [7]. Both of them describe correctly the DGLAP [8] evolution in the limit of low parton density as well as the GLR nonlinear evolution equation [1] in the region of intermediate parton densities.…”

“…The relation between parton density N(x, b t , y) and gluon structure function xG A (x, 1 x 2 ) is given by [6] [9]…”

“…[6] for more details ); 16. All physical obsevables, related to nucleus, are denoted with subscript A while the nucleon observables will be marked by subscript N. Both of these subscripts could be missed if the meaning of the physical quantity is obvious; 17.…”

“…[1] [16] [17] [6] and references therein). In this approximation the GLR -type equation can be solved using characteristics method which leads to existence of a special ( critical ) line.…”