Deep inelastic Scattering, QCD, and generalised vector dominance

Abstract

We provide a formulation of generalised vector dominance (GVD) for low-x deep-inelastic scattering that explicitly incorporates the ${\gamma }^{\ast }\to q\bar{q}$ transition and a QCD-inspired ansatz for the $(q\bar{q})p$ forward-scattering amplitude. The destructive interference originally introduced in off-diagonal GVD is recovered in the present formulation and traced back to the generic structure of two-gluon-exchange as incorporated into the notion of colour transparency. Asymptotically, the transverse photoabsorption cross section behaves as (ln Q^2)/Q^2, implying a logarithmic violation of scaling for F_2, while the longitudinal-to-transverse ratio decreases as 1/ln Q^2.

Comments: 36 pages, 9 figures, revtex