Production of heavy flavours with associated jets at HERA [Elektronische Ressource] / von Oliver Maria Kind. Universität Bonn, Physikalisches Institut

..UNIVERSITAT BONNPhysikalisches InstitutProduction of Heavy Flavourswith Associated Jets at HERAvonOliver Maria KindInclusive cross–sections for the production of open beauty and charm in ep col lisions at HERA recorded with the ZEUS detector in the years 1996—2000 aremeasured. The data is restricted to photoproduction processes, i. e. collision2events with small four–momentum transfers squared, Q ≈ 0. Two associatedjets with transverse energies E > 7(6) GeV and pseudo–rapidities|η|< 2.5 aretrequired. The flavour is tagged by the identification of electrons and positronsfrom semi–leptonic decays of the heavy quark. For this a likelihood method isdeveloped, mainly consisting of energy loss measurements in the central driftchamber of the detector and some other discriminant variables. The fractionsof beauty and charm production are determined by a fit of Monte Carlo tem ¯plates to the data. The total measured production cross–section for bb pro √+20duction is 820 ± 150 pb for centre–of–mass energies s = 300 GeV andep−30√+301170± 130 pb for s = 318 GeV. The total cross–section for charm pro ep−100¯duction is given as well as differential cross–sections for bb and cc¯ production.Post address: BONN IR 2007 04Nußallee 12 Bonn University53115 Bonn December 2006Germany ISSN 0172 8741..