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AZIMUTHAL DISTRIBUTION OF DIJETS IN DIFFRACTIVE DIS. David Šá lek December 8, 2005 Diffractive Meeting, Antwerpen. BOSON GLUON FUSION & TWO GLUON EXCHANGE MODEL. AZIMUTHAL ANGLE. definition of the azimuthal angle in gamma-p CMS. CUTS. DATA. 99-00 data sub-trigger 61 prescale < 15.
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AZIMUTHAL DISTRIBUTIONOFDIJETSINDIFFRACTIVE DIS David Šálek December 8, 2005 Diffractive Meeting, Antwerpen
AZIMUTHAL ANGLE definition of the azimuthal angle in gamma-p CMS
DATA 99-00 data sub-trigger 61 prescale < 15 1223 events
MONTE CARLO RAPGAP inclusive diffraction for F2D(3) at medium Q2 generator: RAPGAP 2.08/18 files from Tinne Anthonis for 99-00 Boson Gluon Fusion 4344 events QCD Compton
QUARK & GENERATED JET CORELATION LEADING JET
QUARK & GENERATED JET CORELATION SECOND JET
GENERATED & RECONSTRUCTED JET CORELATION LEADING JET
GENERATED & RECONSTRUCTED JET CORELATION SECOND JET
AZIMUTHAL ANGLE Problem at generator level: no W-shape Problem at reconstructed level: Lorentz transformation
PROBLEM AT GENERATOR LEVEL azimuthal distribution is not smooth
LORENTZ TRANSFORMATION gamma-p CMS: 4-vector of incoming proton 4-vector of exchanged gamma q = k – k’ k’ not correctly reconstructed it results in deviation of azimuthal distribution at reconstructed level
CORELATION BETWEEN GENERATOR & RECONSTRUCTED LEVEL SCATTERED ELECTRON ENERGY
xPomeron & etamax CORELATION BETWEEN GENERATOR & RECONSTRUCTED LEVEL
COMPARISON OF DATA & MONTE CARLO dead spacal region problem with final state radiation: electron properties basic kinematic variables Lorentz transformation temporary solution: take only those events where there is only the scattered electron in spacal etaLab > -1
FORWARD MUON DETECTORS PROTON REMNANT TAGGER way to improve agreement between data and MC: FMD noise good agreement needed only to calculate luminosity correctly adding FMD noise decreases MC statistics
SUMMARY & OUTLOOK retrieve W-shaped azimuthal distribution for BGF at parton level reconstruct electron properties better in order to reveal generated azimuthal distribution at reconstructed level increase statistics by including events with final state radiation with proper corrections to radiated gammas generate Monte Carlo files with two gluon exchange unfolding