Post on 14-Jan-2016
description
Comparison of EM-objects between 1.5 and 2.5 pedestal
cut.
Emid Meeting
Jean-Roch Vlimant
LPNHE
november 7, 2002
Analysis code from Robert & Marumi– p10.15 results for Z and W
Comparison for run 162594 of Emid objects, Z and W distributions.
p10.15 analysis
From Robert & Marumi W and Z stream files Using their analysis framework Using
EMid cutspT>25 GeV EMfrac>0.9 isolation<0.15 Hmatrix<20 W cut ET > 20 Gev
Z peak
W transverse mass
p11 data Run 162594 taken 1.5 online
– p11 reconstruction recoA_reco_all_0000162594_0**.raw_p11.11.00.root
– 2.5 (~2.1) offline cut + p11 reconstruction recoA_reco_all_0000162594_0**.raw_s11.11.00-1.5.root
MISSING/ZOMBIE: 02,10,16,20,22,36,38,40,41,48,50,55,73,86,87,90
Cuts– Candidates : |id|=11,10
– Good candidates : EMfrac>0.9 isolation<0.15 Hmatrix<50
– Electrons : |id|= 11
– Z : pT>25 GeV ntrack=0,1,2
– W : ET>20 GeV
Effect on candidates2.51.5 : loosing 47% of candidates (68407 35877)
loosing events with multiple candidates.
Effect on good candidates2.51.5 : loosing 25% (32622468)
Hm8<20 22% (19051477)
Effect on electrons2.51.5 : loosing 19% (1010821)
same number of events with 2 electronsHm8<20 17% (462387)
Effect on Emfraction1.5 widens the distribution, more evts at EMfrac>1 and
below 0.9
CUT
Effect on Emfraction1.5 evens the distribution, gain below 0.9 responsible
for loss of good candidates.
CUT
Effect on isolationSmeering towards high isolation for 1.5 responsible for
loss of candidates
Effect on Hmatrix1.5 increases Hmatrix peaks around 10 and 60
CUT
Effect on pT2.51.5 : Loose small pTs
Effect on pT2.51.5 : Loose small pTs
Effect on the di-em eventsnot enough statistics
loss of 5 events from good candaidates
Effect on W transverse massAdd event from good candidates before kinematical edge due to ET increasing
~20
Conclusions from 2.5 to 1.5
Loose 50% of candidates to EMid - need better understanding of isolation.
Loose 25% of good candidates(10,11) – due to Emfrac and isolation, gain for Hmatrix depends on cut value.
Loose 18% electrons(11)- but better identification rates from candidates.
Loose few di-em ? - not enough stats to state.
Add background to W transverse mass distribution
www-d0.fnal.gov/~vlimant/Meeting/CONTRIB/EmidMeeting1.pptwww-d0.fnal.gov/~vlimant/Wps/1.5-2.5sigma-study/nostream/*.ps
www-d0.fnal.gov/~vlimant/Wps/1.5-2.5sigma-study/*.ps