Gluon Radiation in Diffractive Electroproduction

Abstract

Order ${\alpha }_s$-corrections to the diffractive structure functions $F_L^D$ and $F_2^D$ at large $Q^2$ and small $x$ are evaluated in the semiclassical approach, where the initial proton is treated as a classical colour field. The diffractive final state contains a fast gluon in addition to a quark-antiquark pair. Two of these partons may have large transverse momentum. Our calculations lead to an intuitive picture of deep-inelastic diffractive processes which is very similar to Bjorken's aligned-jet model. Both diffractive structure functions contain leading twist contributions from high-$p_{\perp }$ jets.

Comments: 32 pages, 5 figures. Four equations are changed to account for a technical error. The qualitative discussion of the paper is not affected