A unitary model for structure functions and diffractive production at small x

Abstract

We propose a unified approach which describes both structure functions in the small-$x$ region and diffractive production in ${\gamma }^{\ast }p$-interactions. It is shown that the model, based on reggeon calculus and a quark-parton picture of the interaction, gives a good description of available experimental data in a broad region of $Q^2$ (including $Q^2=0$) with a single Pomeron of intercept ${\alpha }_P(0)=1.2$. Predictions for very small $x$ are given and the problem of saturation of parton densities is discussed.

Comments: 43 pages, latex, 15 postscript figures