The EMC effect at low x in perturbative QCD

Abstract

The EMC effect is studied in the perturbative QCD hard pomeron approach. In the limit $x\rightarrow 0$ and for a nucleus with a constant density the effect is found to be a function of a single variable which combines its $x$-, $Q$- and $A$-dependence. At large $Q^{2}$ the effect dies out as $\ln Q/Q$. At small but finite $x$ a change in the anomalous dimension leads to a weaker $Q$-dependence, which almost disappears as $x$ grows and the anomalous dimension becomes small. In this approach the nuclear structure function can be expressed directly in terms of the proton one. Calculations of the EMC effect on these lines give results which agree reasonably well to the existing experimental data for $x<0.05$.