Investigating Fl (x, Q2) at fixed energy in the color dipole formalism

Abstract

At small x, the structure function FL(x,Q2) is driven by the gluon content of the nucleon target and consequently it can unravel the underlying QCD dynamics in that region. In this work, one studies its behavior on the photon virtuality Q2 at fixed energy within the color dipole formalism for models considering parton saturation effects. The reason is that they resum a wide class of higher-twist contributions, which have an important influence on the FL description towards low Q2. It is shown that the geometric scaling property holds for the longitudinal cross section. Moreover, the effective anomalous dimension in the scaling dipole cross sections can be investigated by studing both the turn-over and the large Q2 regions of the recent experimental measurements.