Measurements of Dijet Cross Sections in Diffractive Photoproduction and Deep-Inelastic Scattering at HERA

Measurements are presented of differential dijet cross sections in low |t| diffractive ep collisions of the type ep->eXY, in which the photon dissociation system X is separated from a leading low mass baryonic system Y by a large rapidity gap. The measurements are based on an integrated luminosity of 18/pb. Dijet events are identified using the inclusive kt cluster algorithm. The cross sections are corrected to the level of stable hadrons and are measured in the kinematic region Q^2<0.01 GeV^2 (photoproduction) or 4<Q^2<80 GeV^2 (deep-inelastic ep scattering, DIS) and 165<W<242 GeV, x_pom<0.03, Et(jet1)>5 GeV, and Et(jet2)>4 GeV. Both the photoproduction and the DIS measurement are described within the experimental precision by model predictions based on diffractive parton distributions obtained in inclusive diffractive DIS. The measurements are compatible with QCD and Regge factorisation. The gap survival probability in diffractive dijet photoproduction relative to the same process in DIS is determined to be 0.89+-0.15. This suppression is the same for direct and resolved photon processes.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Heidelberg

Year

2004

Author dc:creator

• Schätzel, Sebastian

Contributors dc:contributor

• Eisele, Franz

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/4419

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:4419