2010/07/31 by Fabrizio Caola, Stefano Forte, Juan Rojo · 1 citation
Physics and Astronomy · #hep-ph
paper · pdf · doi:10.1016/j.nuclphysa.2010.08.009
published as Nucl.Phys.A854:32-44,2011 · Fig. 8 corrected. Published in NPA
arxiv created 2010/10/15 · arxiv updated 2011/03/15
We examine critically the evidence for deviations from next-to-leading order perturbative DGLAP evolution in HERA data. We briefly review the status of perturbative small-x resummation and of global determinations of parton distributions. We show that the geometric scaling properties of HERA data are consistent with DGLAP evolution, which is also strongly supported by the double asymptotic scaling properties of the data. However, backward--evolution of parton distributions into the low x, low Q2 region does show evidence of deviations between the observed behaviour and the next-to-leading order predictions. These deviations cannot be explained by missing next-to-next-to-leading order perturbative terms, and are consistent with perturbative small-x resummation.