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Two I ssues on Resolution. Bertrand, Liwen Dec.16 ,2010. S ome problem of fitting invariant mass still exists Some results on special mc production with single photons. Selection of photon candidates. ph_pt (leading ) > 40 GeV , ph_pt (sub-leading ) > 25 GeV Robust tight photons - PowerPoint PPT Presentation
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Two Issues on Resolution
Bertrand, LiwenDec.16 ,2010
• Some problem of fitting invariant mass still exists
• Some results on special mc production with single photons
Selection of photon candidates
• ph_pt (leading) > 40 GeV, ph_pt (sub-leading) > 25 GeV• Robust tight photons (for both leading and subleading photon)
• ph_trackIsol < 4 GeV (for both leading and subleading photon)
• ph_EtCone40_corrected < 3GeV
Use: mc09_7TeV.106384.PythiaH120gamgam.merge.AOD.e505_s765_s767_r1430_r1429
Correction on photon energy
Comparison of invariant mass reslution
The default one after smearingare not fitted well
Comparison of invariant mass reslution
• Divided into three cases: unconverted photon + unconverted photon unconverted photon + converted photon converted photon + converted photon
unconverted photon + unconverted photon
With smearing
frac : the ratio of crystal ballAlpha, cbmean, cbsigma, n : parameters of crystal ballSigmean, sigwidth : parameters of gaussin
The plots of unconverted +unconverted before smearingis not well fittedDouble guassian
unconverted photon + converted photon
With smearing
frac : the ratio of crystal ballAlpha, cbmean, cbsigma, n : parameters of crystal ballSigmean, sigwidth : parameters of gaussin
converted photon + converted photon
With smearing
frac : the ratio of crystal ballAlpha, cbmean, cbsigma, n : parameters of crystal ballSigmean, sigwidth : parameters of gaussin
Some results on special mc production with single photons
MC:mc10_7TeV.107549.singlepart_gamma_E59p5_eta0p3.recon.AOD.e643_s933_s946_r1657mc10_7TeV.107581.singlepart_gamma_E60p0_eta1p7.merge.AOD.e643_s933_s946_r1657_r1700
dE distribution after some correctiondE=Erec - Etruth
(fixed eta=0.3 and E=59.5GeV)
Correlation among ID variables
eta=0.3 E = 59.5GeV
eta=1.7 E = 60 GeV
Next to do
• Correlation among ID variables• Define new ID variables• Work on more ready MC (fixed eta and E at different value)
• dE = dE(E,eta,Xi)
Better energy resolution better invmass resolution