On phenomenological study of the solution of nonlinear GLR-MQ evolution equation beyond leading order

摘要

We present a phenomenological study of the small-x behavior of gluon distribution function G(x, Q(2)) at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) in light of the nonlinear Gribov-Ryskin-Levin-Mueller-Qiu (GLR-MQ) evolution equation by keeping the transverse size of the gluons (similar to 1/Q) fixed. We consider the NLO and NNLO corrections, of the gluon gluon splitting function P-gg (z) and strong coupling constant alpha(s) (Q(2)). We have suggested semi-analytical solutions based on Regge like ansatz of gluon density G(x, Q(2)), which are supposed to be valid in the moderate range of photon virtuality (Q(2)) and at small Bjorken variable (x). The study of the effects of nonlinearities that arise due to gluon recombination effects at small-x is very interesting, which eventually tames down the unusual growth of gluon densities towards small-x as predicted by the linear DGLAP evolution equation. (C) 2019 Elsevier B.V. All rights reserved.