1. HBHENoieFilter performance in High Pile up and 25 ns Runs Artur Apresyan California Institute of Technology Saeid Paktinat School of Particles and accelerators, IPM

2. Introduction R45 = (T4 – T5)/(T4 + T5) T4 and T5 are in GeV. Number of the vertices is used as the PU measure. GoodPrimaryVertexFilter is applied. HBHENoiseFilter is NOT applied to study the Individual entries of the filter. 18-Nov-112

3. Data Datasets: – /MinimumBias/Run2011A-PromptReco-v5/RECO – /ZeroBiasHPF0/Run2011B-PromptReco-v1/RECO (High Pile up) – /L1MuHPF/Run2011B-PromptReco-v1/RECO (High Pile up) – /ZeroBias/Run2011B-14Oct2011-v1/RECO (25 ns) – /L1Mu/Run2011B-14Oct2011-v1/RECO (25ns) Json file 23 Sep for MinimumBias Sample only – Cert_160404-176309_7TeV_PromptReco_Collisions11_JSON.txt 18-Nov-113

4. Number of Vertices in different Runs 18-Nov-114 Nevents: MinumBias 1.6 M High Pile Up 3.7 M 25 ns 830 k

5. 18-Nov-115 Individual entries for HBHEFilter RBXHits (nHits (E>1.5GeV) in a RBX) No cut in the current version of the filter Same feature is seen in low pile up events

6. Individual entries for HBHEFilter HPD Hits (nHits (E>1.5GeV) in a HPD) 18-Nov-116 Different Behaviours

7. Individual entries for HBHEFilter Total Zeros (nChannels with zero energy in a RBX) HPD No other Hits (nHits found in a HPD with no other hits in RBX) 18-Nov-117 Almost the same distributions

8. Individual entries for HBHEFilter Has Bad RBX TS4 TS5 18-Nov-118 Significant difference is seen in different datasets, specially for 25ns sample. 11150 out of 830K events rejeted

9. Individual entries for HBHEFilter Has Bad RBX TS4 TS5 18-Nov-119 Same feature is seen in other datasets. To do: Revisit the R45 cuts to adjust the efficiency. 22000 out of 1.3M events rejeted

10. Jet ET vs Had Fraction in different samples for events that pass or fail the filter 18-Nov-1110 Had Fraction is ~1 MinimumBias 2011A ZeroBias High Pile up ZeroBias 25 ns

11. Jet ET vs EM energy in different samples for events that pass or fail the filter 18-Nov-1111 EM energy is very small MinimumBias 2011A ZeroBias High Pile up ZeroBias 25 ns

12. Suspicious events not flagged as noise DelatPhi between the leading jet and the met vector is more pronounced close to 3.14 for the noise. Some “No noise” events in this region are scanned. 18-Nov-1112

13. Met Distribution 18-Nov-1113 Even a moderate cut on Met can kill most of the noisy events.

14. Suspicious event in High pile up dataset 18-Nov-1114 Fully hadronic jet back to back with met!

15. Suspicious event in 25ns dataset 18-Nov-1115 Fully hadronic jet back to back with met!

16. Coclusion & outlook The treatment of the individual components of the HBHENoiseFilter are studied in different regimes of pile up. Some components are highly affected by new conditions. They will be revisited to adjust the filter efficiency. 18-Nov-1116

17. Back up 18-Nov-1117

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