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Persistent URL http://purl.org/net/epubs/work/29680
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Record Id 29680
Title The Performance of the ZEUS First Level Tracking Trigger and a Study of Diffractive D* Production in Deep Inelastic Scattering at HERA
Abstract A study of the performance of the ZEUS first level tracking trigger during its first year of full operation, 1996, is presented. The trigger is shown to be very effective in rejecting beam-gas background whilst retaining data from ep collisions with high efficiency. The efficiency for finding individual tracks is high, over 95%, and tracks are identified as originating from the nominal vertex region with an efficiency of over 80%. Detailed investigations of the operation of individual processing stages of the trigger have been performed, and suggestions how to further improve the tracking trigger performance are presented. Using 6.3 pb(-1) of data taken with the ZEUS detector during 1995, the diffractive production of charmed quarks in neutral current deep inelastic scattering at HERA is studied. Charm is tagged by reconstructing D* mesons in the decay channel D*(+/-)-->D((-)0)pi(+/-)-->K(-/+)pi(+/-)pi(+/-), and the presence of a large rapidity gap identifies a diffractive event. A diffractive D* cross-section of 770+/-210(stat)(+250)(-140)(syst) pb is measured in the kinematic region 10<Q(2)<80 GeV(2), 0.04<y,0.7, p(t)(D*)>1.0 GeV/c, mod(eta(D*))<1.5, and the ratio of diffractive to total D* production in this kinematic region is found to be large, 21+/-6(stat)(+7)(-4)(syst)%.
Organisation CCLRC
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Language English (EN)
Type Details URI(s) Local file(s) Year
Thesis RAL Theses RAL-TH-1998-010. 1998. 1998