Deviations from NLO QCD evolution in inclusive HERA data

We search for deviations from next-to-leading order QCD evolution in HERA structure function data We compare to data predictions for structure functions in the small x region, obtained by evolving backwards to low Q(2) the results of a parton fit performed in the large Q(2) region, where fixed-order perturbative QCD is certainly reliable. We find evidence for deviations which are qualitatively consistent with the behaviour predicted by small x perturbative resummation, and possibly also by non-linear evolution effects, but incompatible with next-to-next-to-leading order corrections (C) 2010 Elsevier B V All rights reserved