The dipole cross section by the unintegrated gluon distribution at small $x$

Abstract

We apply a previously developed scheme to consistently include the improved saturation model for the unintegrated gluon distribution (UGD) in order to evaluate, in the framework of $k_{t}$ factorization, at small $x$ at the next-to-leading order (NLO) in $\alpha_{s}$. We start the unintegrated gluon distribution with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section, which preserves its behavior success in a wide range of $k_{t}^{2}$ in comparisons with the UGD models (M. Hentschinski, A. Sabio Vera and C. Salas (HSS), I.P.Ivanov and N.N.Nikolaev (IN) and G. Watt, A.D. Martin and M.G. Ryskin (WMR)) . These results show that the geometric scaling holds for the improved saturation model in a wide kinematic region $rQ_{s}$, and are comparable with the Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) model. The unintegrated gluon distribution at low and high momentum transfer in a wide range of $x$ is considered.