How fast do small x structure functions rise? A comparative analysis

We parametrize the small x, singlet component of the proton structure function F2 by powers and logarithms of 1/x for discrete values of Q2 between 0.2 and 2000 GeV2, and compare these parametrizations by applying the criterion of minimal χ2. The obtained values of the fitted parameters may be used to study the evolution of F2 in Q2 and/or in discriminating between dynamical models. A slowing-down in the increase of F2 towards highest available values of Q2 is revealed. The effect is quantified in terms of the derivative dlnF2(x,Q2)/dln(1/x).