Monophoton Analysis Selection Criteria (1 June 2011)

These are selections for the Monophoton analysis. To see working implementations of these requirements, please also see these macro.

At the event level

1. Remove scraping events by requiring Scraping_isScrapingEvent is false.

2. Passed at least one of:

• HLT_Photon30_Cleaned_L1R
• HLT_Photon30_Isol_EBOnly_Cleaned_L1R_v1
• HLT_Photon30_L1R)

3. has at least one "good" vertex defined by:

• ndof>4
• |z|<=24.
• |d0|<=2.
• isFake==false

4. Removal of cosmic/halo:

veto events that have a Cosmic Muon present. For example:

Bool_t hasCosMuon=kFALSE;
for (int kk=0;kk<CosmicMuon_n;++kk){
  if (CosmicMuon_OuterTrack_isNonnull[kk]==1 && CosmicMuon_isStandAloneMuon[kk]==1)
    hasCosMuon=kTRUE;
}
if (hasCosMuon) continue;

At the photon level:

5. Photon selection

Tight fiducial barrel photon, with pt>30

• sig_ieie < 0.013
• fabs(Photon_sc_eta<1.4442 //barrel fiducial region
• Photon_pt> 30.
• Photon_ecalRecHitSumEtConeDR04 < 4.2+0.006*Photon_pt
• Photon_hcalTowerSumEtConeDR04< 2.2+0.0025*Photon_pt
• Photon_HoE < 0.05
• Photon_trkSumPtHollowConeDR04 < 2.0+0.001*Photon_pt
• Photon_hasPixelSeed==false//pixel veto

6. Electron selection:

Same as photon selection, but require a pixel seed. (Photon_hasPixelSeed==true//pixel veto)

7. MET selection:

TCMet>30 GeV selection.

If you are considering out-of-time EM objects you must be careful to re-compute MET if there is a photon with |time| > 3 ns (see pseudo-code). Ignore this correction if you just want prompt events (be sure to include requirement #10!!)

   METX = TCMetPt * cos(TCMetPhi)
   METY = TCMetPt * sin(TCMetPhi)
   if not prompt
     METX = METX - Photon_pt*cos(Photon_phi)
     METY = METY - Photon_pt*sin(Photon_phi)
   newMET = sqrt(METX*METX + METY*METY)

8. Removal of spikes:

• | LICTD | < 5 for real photons. LICTD = Largest IntraCluster Time Difference. Keep photons if the absolute difference of t_seed and t_outlier < 5 ns. Here, t_outlier is the time of the photon's constituent rechit that deviates most from t_seed.

9. Removal of isolated spikes:

As of now, we require good photons to have sigma_ietaieta > 0.001 and sigma_iphiiphi > 0.001.

10. Prompt time:

|Seed time| < 3ns

Monophoton selection

Require 1-5,7-10.

Zee selection

Pick two electrons (photon+pixSeed) that pass 5 and are not within each other's isolation regions (require dR>0.8). Require 1-4, 6, 8-10.

Wenu selection

Pick one electrons (photon+pixSeed) that pass 5 and have MET. Require 1-4, 6-10.

-- TiaMiceli - 04-May-2011