Nonlinear corrections to the DGLAP equations in view of the HERA data

Abstract

The effects of the first nonlinear corrections to the DGLAP evolution equations are studied by using the recent HERA data for the structure function F 2 (x, Q 2 ) of the free proton and the parton distributions from CTEQ5L and CTEQ6L as a baseline. By requiring a good fit to the H1 data, we determine initial parton distributions at Q 2 0 = 1.4 GeV 2 for the nonlinear scale evolution. We show that the nonlinear corrections improve the agreement with the F 2 (x, Q 2

Contributions of gluon recombination to saturation phenomena

“…Obviously, this conclusion is different from the work [9], which uses the GLR-MQ equation to backward evolve the parton distributions from the input distributions of a free proton at very higher Q 2 , where the nonlinear terms are negligible. They give Q 2 s ∼ 3 − 20GeV 2 at 10 −5 < x < 10 −2 for Pb(A = 208) [9]. One can understand the above mentioned difference as follows.…”

“…The reason is that the parton distributions at higher Q 2 always remember the recombination effects in their evolution process. Therefore, a larger, but not true, input distribution in the nuclear target predicted a stronger recombination effect in work [9], which may balance the parton splitting effect in the evolution, and give a solution in Eq.…”

Study of the Fundamental Structure of Matter With an Electron-Ion Collider

“…It is widely believed that shadowing is a leading twist effect (97,98), but some of the IMF discussion in the CGC saturation framework suggests higher twist effects are important for Q 2 ≤ Q 2 s because of the large gluon density (99). Constraints from non-linear corrections to the DGLAP framework have also been discussed recently (100). The available data on the Q 2 dependence of shadowing are inconclusive at small x.…”

Nuclear PDFs in the beginning of the LHC era

“…The theoretical expectations are that the Q −n -type power corrections in Eq. (1) become enhanced in nuclear environment and could eventually be seen even at perturbative scales [13]. The search for such a transition from the linear DGLAP dynamics to a non-linear regime is also one of the main goals of the LHC proton+lead program [14,15].…”