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Missing Et Before and After Shutdown

Missing Et Before and After Shutdown. Yuri Gershtein. The Problem. Di-EM skim: 2 EM objects Et>7 GeV ~3% of the data

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Missing Et Before and After Shutdown

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  1. Missing Et Before and After Shutdown Yuri Gershtein

  2. The Problem • Di-EM skim: • 2 EM objects Et>7 GeV • ~3% of the data • MET in gg events with all clean-up cuts except H-matrix (i.e. signal + background together) • Tails are obviously worse in the post-shutdown data –WHY? Run < 172K Run > 172K Yuri Gershtein - CALO Meeting

  3. Bad runs? • Hypothesis: may be the looser selection criteria for post-shutdown data make a difference? Fraction of events with MET>20 GeV all events from diEM skim I II III Moriond Sample What happened after run 175500? run Yuri Gershtein - CALO Meeting

  4. Bad runs? Fraction of events with MET>20 GeV Good runs from diEM skim Bad runs from diEM skim run Yuri Gershtein - CALO Meeting

  5. Two hot regions II III All events All events MET > 20 GeV MET > 20 GeV MET Azimuth MET Azimuth jets EM objects Yuri Gershtein - CALO Meeting

  6. End of Story? • Both hot zones are not present after my cleanup cuts – only CC em’s and no jets in ICD region All events Good runsTwo hot spots removed MET Yuri Gershtein - CALO Meeting

  7. MET before – after shutdown Normalized at MET<20 GeV x2 difference at MET>40 x5 difference at MET>120 MET Yuri Gershtein - CALO Meeting

  8. MET v.s. MET Azimuth MET azimuth III MET > 30 GeV MET MET > 50 GeV MET > 100 GeV MET azimuth Yuri Gershtein - CALO Meeting

  9. Event from the peak • The event has two isolated EM objects – simple cone clustering… Yuri Gershtein - CALO Meeting

  10. Run dependence? • MET azimuth v.s. run for MET > 30, 50 and 100 GeV • 162K <run< 172K – clean • run < 162 K – worse • run > 172 K – a mess… Yuri Gershtein - CALO Meeting

  11. Zoomed For Run > 172K Almost all data is affected Worst for run > 176184 (Apr 26, after a 4 day shutdown…) Yuri Gershtein - CALO Meeting

  12. Look for more hot regions • EM objects, Et > 20 GeV • Run range I (run < 162 K) • good runs azimuth detector eta Yuri Gershtein - CALO Meeting

  13. Look for more hot regions MET > 30 • EM objects, Et > 20 GeV • Run range II (162K < run < 172 K) • Good runs All events MET > 30, HM > 50 Yuri Gershtein - CALO Meeting

  14. Look for more hot regions MET > 20 • EM objects, Et > 20 GeV • Run range III (run > 172 K) • Good runs, hot spots removed All events MET > 20, HM > 50 More than ten hot areas!! Yuri Gershtein - CALO Meeting

  15. Hot EM regions • It seems that there is always some energy in these hot areas: • no good EM particles in these areas… Hot EM Normal EM (same eta) Hot EM Normal EM (same eta) HMatrix Chi2 HMatrix Chi2 Yuri Gershtein - CALO Meeting

  16. Hadronic Hot Regions • Run <162 K, good runs, leading jet, MET>30 Yuri Gershtein - CALO Meeting

  17. Hadronic Hot Regions • 162< run<172 K, good runs, leading jet MET > 30 MET > 50 Yuri Gershtein - CALO Meeting

  18. Hadronic Hot Regions • run>172 K, good runs, leading jet, MET>50 Yuri Gershtein - CALO Meeting

  19. Summary (1) • Need better monitoring of the calorimeter • The typical failure mode in the data is a hot cell/tower/BLS/ADC/… which is • fires at a relatively small rate invisible in distributions like jet eta-phi for all events, need monitoring for events with large MET • persistent through a long period of time • have relatively small energies, from 30-40 GeV to very small… Yuri Gershtein - CALO Meeting

  20. Summary (2) • Is the data recoverable? • Almost all post-shutdown data is affected • Possible ways to recover • may be the hardware signature can be recognized (similar to the BLS recovery)? • may be the cells (if these are cells!!) should be excluded from MET calculation? • may be just reject events with energy in the hot areas? – easiest to do, hardest to calculate efficiency of – plus, there are A LOT of hot areas  Yuri Gershtein - CALO Meeting

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