Small x behavior of parton distributions. Analytical and «frozen» coupling constants. BFKL corrections

Abstract

It is shown that in the leading twist approximation of the Wilson operator product expansion with "frozen" and analytic strong coupling constants, Bessel-inspired behavior of the structure functions F 2 and F cc 2 and also the derivative ∂ ln F 2 /∂ ln(1/x) at small x values, obtained for a flat initial condition in the DGLAP evolution equations, leads to good agreement with the deep inelastic scattering experimental data from HERA.

Parton distributions at low x and gluon- and quark average multiplicities

“…The resummation leads to the Bessel-like form of the "+" component. Including all orders of the perturbation theory should lead to a power-like form as it was predicted in the framework of BFKL approach[8] (see discussion in[54]).…”

“…The comparison of the generalized DAS approach predictions with the data for the slope ∂ ln F 2 /∂ ln(1/x) [4] and for the heavy parts of F 2 [5] can be found in Refs. [52,48] and [53], respectively (see also the review [54]). An estimation of the cross-sections of very high-energy neutrino and nucleon scattering has been found in [55].…”

Q 2 evolution of parton distributions at small values of x: Effective scale for combined H1 and ZEUS data on the structure function F 2

“…In particular, the resummation proposed by Balitsky, Fadin,Kuraev,and Lipatov [14] may prove to be useful here (see [15]). In accordance with the discussion in [16], this resummation can be included in the generalized DAS approach.…”