Eur. Phys. J. C 20, 313-321
DOI: 10.1007/s100520100661

Diffractive parton distributions from the saturation model

K. Golec-Biernat^{1, 2} and M. Wüsthoff<sup>3

1</sup>  II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
²  H. Niewodniczanski Institute of Nuclear Physics, Radzikowskiego 152, 31-342 Kraków, Poland
³  Department of Physics, University of Durham, Durham DH1 3LE, UK

(Received: 22 February 2001 / Revised version: 22 March 2001 / Published online: 3 May 2001 -© Springer-Verlag / Società Italiana di Fisica 2001)

Abstract
We review diffractive deep inelastic scattering (DIS) in the light of the collinear factorization theorem. This theorem allows one to define diffractive parton distributions in the leading twist approach. Due to its selective final states, diffractive DIS offers interesting insight into the form of the diffractive parton distributions which we explore with the help of the saturation model. We find Regge-like factorization with the correct energy dependence measured at HERA. A remarkable feature of diffractive DIS is the dominance of the twist-4 contribution for small diffractive masses. We quantify this effect and make a comparison with the data.

© Società Italiana di Fisica, Springer-Verlag 2001