The Rise in F_2^p at HERA

Abstract

We show that the rise in $F_2^p$ at small $x$ and large $Q^2$ seen at HERA is indeed the non-Regge double asymptotic scaling behaviour expected from the perturbative emission of strongly ordered hard gluons. An alternative explanation, in which there is no strong ordering, and a new hard Reggeon is generated, is also tried but found wanting: its theoretical short-comings are betrayed by its failure to properly account for the HERA data.