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This meeting outline discusses the missing PT projection fraction method and its use in calculating jet response. It also covers cuts and selection criteria, as well as results on hadronic response, EM calibration, and gamma + jets.
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Z + Jet Calibration Studies Michele Petteni Imperial College MichelePetteniDØHiT Meeting
Outline • The missing PT projectionfraction method and its use in calculating the jet response. • Outline of cuts and selection. • Results: • Hadronic response. • EM calibration. • + jets. MichelePetteniDØHiT Meeting
MPF (1) • Method used in Run I to calibrate jets using + jets sample. • Based on momentum conservation in the transverse plane. • Z and jet produced back to back in r- plane. MichelePetteniDØHiT Meeting
MPF (2) • For perfect response: PT(Z) + PT(recoil) = 0 • Real life: PTmeas(Z) + PTmeas(recoil) = - MPTmeas • Define: PTmeas(recoil) = Rhad· PT(recoil) • Re-arrange and assume EM corrected: MichelePetteniDØHiT Meeting
Sample • Using 50 K Zee events from rootuples in SAM • Generated using pythia with <mb> =2.5, reconstructed with psim 01.02.00 and p05.00.04 • Includes Drell-Yan and , /Z interference. MichelePetteniDØHiT Meeting
Cuts and Selection • Cuts: • Select 2 highest E reco em objects • ||leptons < 2.5, • Construct Z from 2 em objects • PT(Z) > 10 GeV • 61.0 < M(Z) < 121.0 • 2.942 < j - Z < 3.342. • Select events with only 1 jet in window. MichelePetteniDØHiT Meeting
R Fit • R defined as before. • Define E' = PT(Z) · cosh(j) • Fit response plots using functional form: a + b ln E + c (ln E)2 MichelePetteniDØHiT Meeting
E vs. E’ MichelePetteniDØHiT Meeting
R vs. E’ MichelePetteniDØHiT Meeting
R vs. E’ (2) MichelePetteniDØHiT Meeting
Fit for Central Region MichelePetteniDØHiT Meeting
R from + jets MichelePetteniDØHiT Meeting
EM Calibration (1) MichelePetteniDØHiT Meeting
EM Calibration (2) MichelePetteniDØHiT Meeting
Photon Response MichelePetteniDØHiT Meeting
R from + jets (2) MichelePetteniDØHiT Meeting