1. Converted photon and π0 discrimination based on H  cut-based analysis
Zhen Zhang IHEP

2. CSA07 samples converted photon candidate from: π0 from: 160000 events
/H120_gammagamma_gluonfusion/CMSSW_1_6_7-CSA /RECO
events
π0 from:
/Gamjet/CMSSW_1_6_7-CSA /RECO
1.1M events
/Jets_Pt50up/CMSSW_1_6_7-CSA /RECO
1 M events

3. I. converted photon and π0 candidates selection
Converted photon candidates are selected as H to   cut-based selection (PTDR) :
Photon selection: photon candidates are reconstructed using the hybrid clustering algorithm in the barrel and the island clustering algorithm in the endcaps
ET1, ET2 > 30GeV (release to Et>40, 25 GeV now)
|η|<2.5
Isolation
No tracks with pt>1.5 GeV present within ΔR<0.3 around the direction of the photon candidate. We consider tracks with hits in at least two layers of the silicon pixel detector.
Sum of Et of the ECAL basic clusters within 0.06<ΔR<0.35 around the direction of the photon candidate <6 GeV in barrel, <3 GeV in endcaps
Sum of Et of the HCAL towers within ΔR<0.3 around the direction of the photon candidate<6 GeV(5 GeV) in barrel (endcaps)
If one of the candidates has |eta|> the other has to satisfy also: Sum of Et of the ECAL<3, Sum of Et of the HCAL<5 GeV

4. Number of tracks associated with a SuperCluster for converted photon

5. The reason of one track corresponding to a SuperCluser

6. In the TMVA analysis, I will study the SuperCluter has a track and more that one track separately

7. Input variables for one track case

8. Input variables for one track case

9. training and test results

10. BDT training and test output

11. Input variables for more than one track case

12. Input variables for more than one track case

13. training and test results

14. BDT training and test output

15. TMVA application
I will select the converted photon candidate in gamma jet sample.
The criterion is that the converted photon candidate does not corresponding a photon at generator lever, i.e., exclude the prompt photon.

16. The BDT output in application
one track case
more thanone track case
47%
48%
The BDT output shape of converted photon candidate from pi0 in gamma jet sample is almost the same as the training shape. This support our result is believable. For reject rate(48%.47%) is lower than training resluts(55,50%) is caused by the variable conpho_closestSC_dR which depends on sample to some extent.

17. Converted photon and pi0 discrimination in CMS NOTE IN 2007/032 provided by G.Anagnostou
the results from ORCA
the results from CMSSW, so I don’t use it in the analysis

18. Some discusses on my thesis
the title of my thesis：
How to organize the four chapters of HZ gamma, HVV, converted photon and pi0 discrimination and cosmic ray analysis?