1. Jean-Roch Vlimant LPNHE november 6, 2002
Comparison of EM-objects between 1.5 and 2.5 pedestal cut. Emid Meeting
Jean-Roch Vlimant
LPNHE
november 6, 2002

2. Analysis code from Robert & Marumi
p10.15 results for Z and W
Comparison for run of Emid objects, Z and W distributions.

3. p10.15 analysis From Robert & Marumi W and Z stream files
Using their analysis framework
Using EMid cuts pT>25 GeV EMfrac>0.9 isolation<0.15 Hmatrix<20 W cut ET > 20 Gev

4. Z peak

5. W transverse mass

6. p11 data Run 162594 taken 1.5 online Cuts
p11 reconstruction recoA_reco_all_ _0**.raw_p root
2.5 (~2.1) offline cut + p11 reconstruction recoA_reco_all_ _0**.raw_s 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

7. Effect on candidates 2.51.5 : loosing 47% of candidates (68407 35877) loosing events with multiple candidates.

8. Effect on good candidates 2. 51
Effect on good candidates 2.51.5 : loosing 25% (32622468) Hm8<20 22% (19051477)

9. Effect on electrons 2.51.5 : loosing 19% (1010821) same number of events with 2 electrons Hm8<20 17% (462387)

10. Effect on Emfraction 1.5 widens the distribution, more evts at EMfrac>1 and below 0.9
CUT

11. Effect on Emfraction 1. 5 evens the distribution, gain below 0
Effect on Emfraction 1.5 evens the distribution, gain below 0.9 responsible for loss of good candidates.
CUT

12. Effect on Emfraction after pT cut at 15 GeV effect is less important below 0.9
added
CUT

13. Effect on isolation Smeering towards high isolation for 1
Effect on isolation Smeering towards high isolation for 1.5 responsible for loss of candidates

14. Effect on isolation after pT cut at 15 GeV 1
Effect on isolation after pT cut at 15 GeV 1.5 candidates are noisy ( negative isolation)
added

15. Effect on Hmatrix 1.5 increases Hmatrix peaks around 10 and 60
CUT

16. Effect on Hmatrix after pT cut at 15 GeV Hmatrix cut is no longer different below 50
added

17. different populations pt versus Hmatrix8 at 2.5 NO pT cut
added
Low pT uniform in Hmatrix
~60 Hpeak is ~15 pT peak
Candidates after both cuts

18. different populations pt versus Hmatrix8 at 1.5 NO pT cut
added
Low pT uniform in Hmatrix
~60 Hpeak is ~15 pT peak
Candidates after both cut

19. Changes after global normalization
added
2.5
1.5
Peak increases
Low pT disapear

20. Effect on pT 2.51.5 : Loose small pTs

21. Effect on pT 2.51.5 : Loose small pTs

22. Effect on the di-em events not enough statistics loss of 5 events from good candaidates

23. Effect on W transverse mass Add event from good candidates before kinematical edge due to ET increasing
~20

24. 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.ppt
www-d0.fnal.gov/~vlimant/Wps/ sigma-study/nostream/*.ps
www-d0.fnal.gov/~vlimant/Wps/ sigma-study/*.ps