Implications of scaling violations of F2 at HERA for perturbative QCD

Abstract

We critically examine the QCD predictions for the Q 2 dependence of the electron-proton deep-inelastic structure function F 2( x, Q 2) in the small x region, which is being probed at HERA. The standard results based on next-to-leading order Altarelli-Parisi evolution are compared with those that follow from the BFKL equation, which corresponds to the resummation of the leading log ( 1 x ) terms. The effects of parton screening are also quantified. The theoretical predictions are confronted with each other, and with existing data from HERA.