Measurement and QCD analysis of diffractive jet cross sections in deep inelastic scattering at HERA [Elektronische Ressource] / presented by Matthias Ulrich Mozer

DISSERTATIONsubmitted to theCombined Faculties for the Natural Sciences and Mathematicsof the Ruperto-Carola University of Heidelberg, Germanyfor the degree ofdoctor rerum naturaliumpresented byMatthias Ulrich Mozer, M.S.born in Hannover, GermanythOral examination: July 24 2006Measurement and QCD Analysisof Diffractive Jet Cross Sectionsin Deep-Inelastic Scattering at HERAReferees: Prof. Dr. Franz EiseleProf. Dr. Otto NachtmannAbstractDifferential cross sections for the production of two jets in diffractive deep inelasticscattering (DIS) at HERA are presented. The process studied is of the typeep→eXY, where the central hadronic system X contains at least two jets and isseparated from the system Y by a gap in rapidity. The forward system Y consistsof an elastically scattered proton or a low mass dissociation system.The data were taken with the H1 detector during the years of 1999 and 2000 and−1correspond to an integrated luminosity of 51.5 pb .The measured cross sections are compared to fixed order NLO QCD predictions,that use diffractive parton densities which have previously been determined bya NLO QCD analysis of inclusive diffractive DIS at H1. The prediction and thedata show significant differences. However, the dijet cross section is dominatedby the diffractive gluon density, which can be extracted by the above mentionedanalysis only with considerable uncertainty.