1. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring1 HCAL Noise Identification and Filtering (HPD behavior and noise identification) Shuichi Kunori 10-Dec-2008 - draft -

2. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring2 Sources of fake MET/HMT and jets Calorimeter resolution  MET resolution –Clustered energy Leading jet(s) have the most impact. –Un-clustered energy Detector effect –ECAL/HCAL Hot/dead channels ECAL APD Nuclear counter effect HB/HE HPD/RBX noise  CRAFT Showers in fibers in 53 degree gap HF PMT/fiber events (behind the HF absorber) –Gap/thin part eta=0.0 – air gap (covered by HOR0) eta=1.5 – thin/dead material (complex material distribution) Eta=3.0 – Endcap edge effect, ES support Other non-collision events –Cosmic muons (showers)  CRAFT –Beam halo We designed and built a very hermetic calorimeter for good measurement of large MET. The MET distribution should behave nicely, but… Several sources are known to create “tail” in the MET distribution (and jets). We identify such events and filter them out during event reconstruction and physics analysis.

3. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring3 HPD Noise Rate in the first CRAFT run Edward Laird R66594

4. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring4 HPD Noise Spectrum (pedestal not subtracted) 40MHz 40Hz 0.4Hz 0 2 12 40 GeV pedestal Ion feedback discharge 10 9 HCAL noise: Coincidence with physics signal is very small, but large noise will appear in the tail of the MET distribution once they are picked up by jet/met trigger. Mehmet Deliomeroglu CRAFT

5. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring5 CRUZET: Alfredo Gurrola / Latife Nukhet Vergili / Ming Yan Discharge (>60 fC)

6. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring6 Low energy coherent noise - Need a jet trigger CRUZET3

7. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring7 Red: RBX noise – Noise in multiple HPD’s Blue: HPD noise (ion feedback etc.) – HPD hits < 9 Magenta: HPD Noise (discharge) – HPD hits >= 9 HCAL Trigger Jet trigger HPD # of hits HCAL Noise in CRAFT Ion feedback: 5- 60 GeV RBX noise: 60-380 GeV Discharge: >380GeV Energy in RBX Taylan Yetkin / sk

8. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring8 Two Levels of Filter HCAL Noise filter – at RecHit creation stage –RBX-by-RBX Using timing and pulse shape (+ hit multiplicity) –Out-of-time pile-up will be issue. Implicitly using pattern of hits in phi slice(s) –Good synchronization required. Monitor latency jump and phase shift. Align BX during RecHit creation. JetsMET Noise filter – at Physics analysis stage –Topology in eta-phi-depth space EM fraction Jet shape … –Correlation with ECAL, Tracker and MUON detectors Timing Existence of tracks

9. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring9 HCAL Noise Filter Step-1: Timing distribution cut Red: RBX noise Blue: HPD ion feedback (n<9) Magenta: HPD discharge (n>8) RMS of RecHit time in RBX (E>1.5GeV) - multi hit events - ns # of hits in RBX (E>1.5GeV) hits 72 18 9 TB2007 HE 30GeV pi- 4(  ) x 2(  ) x 2 (d) TB2007 HE 300GeV pi- 4(  ) x 2(  ) x 2(d) Suvadeep Bose 20ns sk

10. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring10 Pulse Shape (TB2006) 3ts 10ts Ratio: E(3ts) / E(10ts) Cut on Pulse Shape Some noise: - wider or - irregular pattern in 10 time slieces 8 0.25 E3/E10 Introduced by Edward Laid 17-july-2008 # of ADC count 0’s in RBX

11. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring11 MET Rates Muon Triiger 0.01 Hz at MET 100GeV 0.3 Hz at Met 100GeV after the filter. 0.2 Hz @ 10E33 Rate for 8E29 Gheorghe Lungu Jet Trigger blue – no cut red – after cuts on time spread and pulse shape

12. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring12 Use CRAFT data to develop a tool to monitor HCAL noise/Anomalous events in MET events. Latife Nukhet Vergili / Taylan Yetkin Development of Monitoring Tool Oct.18Nov.08 3 weeks Runs with > 5M events

13. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring13 Conclusion We have good CRAFT data to study fake jets/MET due to HCAL noise and cosmic muons. We use those to develop HCAL noise filter algorithm and monitoring tool. We plan to create two levels of filters. –Level 1 - HCAL noise filter during RecHit creation –Level 2 - Fake JetMET filter during physics analysis Development of algorithm has started. Significant Monte Carlo study is required to optimize the filter algorithm for the maximum rejection of fake and the least bias to physics signal. We have been watching for anomalous events during testbeam, CRUZET and CRAFT. We continue doing so and develop a monitoring tool for physics run/physics analysis.

14. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring14 Additional slides

15. 10-Dec-2008 / S.KunoriHCAL Noise Identification and Monitoring15 Additional cuts Edward Laid 17-july-2008 Charge in 10 ts Charge in late 3ts nominal pulse shape Calo MET