Scaling Violations in the $Q^2$ Logarithmic Derivative of $F_2$

Abstract

We examine the latest HERA experimental measurements of the $Q^2$ logarithmic derivative of the proton structure function. We analyze the characteristics of DGLAP with and without screening, as well as a Regge type model, and compare their predictions to all available data on $\text{slope}$ including those for fixed W. Our results show that the present data can be described in pQCD taking into account shadowing corrections. However, such a description cannot be considered a conclusive signal of gluon saturation since the experimental data on $\text{slope}$ do not allow one to discriminate between the various approaches, in spite of their very different construction.

Comments: 15 pages, & figs in eps files