Pentaquark Search at Hermes

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Pentaquark
Wolfgang Lorenzon
Collaboration 7 November 2003
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Introduction
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Experimental Evidence from HERMES
quasi-real photo production on deuterium target
with decay mode Q? p K0s ? p pp-
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Data Set, Event Reconstruction, Cuts
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Proton Identification
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KS Identification
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M(p pp-) Spectrum
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M(p pp-) Spectrum with naïve Background Model
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Various (motivated) Background Models
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Significance
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Detector Mass Calibrations
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Q Mass
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Comparison with other Experiments
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Monte Carlo Simulation
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Q Isopsin (prelim.)
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Conclusions
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Experimental Evidence for Q