Missing Et Before and After Shutdown
Yuri Gershtein
7/8/2003 Yuri Gershtein - CALO Meeting 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
7/8/2003 Yuri Gershtein - CALO Meeting 3
Bad runs? Hypothesis: may be the looser selection criteria for post-shutdown data make a difference?
run
Fraction of events with MET>20 GeV
What happened after run 175500?
all events from diEM skim
Moriond Sample
I II III
7/8/2003 Yuri Gershtein - CALO Meeting 4
Bad runs?
run
Fraction of events with MET>20 GeV
Good runs from diEM skim
Bad runs from diEM skim
7/8/2003 Yuri Gershtein - CALO Meeting 5
Two hot regions
All events
MET > 20 GeV
All events
MET > 20 GeV
MET Azimuth MET Azimuth
jets
EM objects
II III
7/8/2003 Yuri Gershtein - CALO Meeting 6
End of Story?
All events Good runs Two hot spots removed
Both hot zones are not present after my cleanup cuts – only CC em’s and no jets in ICD region
MET
7/8/2003 Yuri Gershtein - CALO Meeting 7
MET before – after shutdown
MET
Normalized at MET<20 GeV
x2 difference at MET>40
x5 difference at MET>120
7/8/2003 Yuri Gershtein - CALO Meeting 8
MET v.s. MET Azimuth
MET
MET azimuth
MET azimuth
MET > 30 GeV
MET > 50 GeV
MET > 100 GeV
III
7/8/2003 Yuri Gershtein - CALO Meeting 9
Event from the peak
The event has two isolated EM objects – simple cone clustering…
7/8/2003 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…
7/8/2003 Yuri Gershtein - CALO Meeting 11
Zoomed For Run > 172KAlmost all data is
affectedWorst for run > 176184
(Apr 26, after a 4 day shutdown…)
7/8/2003 Yuri Gershtein - CALO Meeting 12
Look for more hot regionsEM objects, Et > 20 GeVRun range I (run < 162 K) good runs
detector eta
azimuth
7/8/2003 Yuri Gershtein - CALO Meeting 13
Look for more hot regionsEM objects, Et > 20 GeVRun range II
(162K < run < 172 K)Good runs
All events
MET > 30
MET > 30, HM > 50
7/8/2003 Yuri Gershtein - CALO Meeting 14
Look for more hot regionsEM objects, Et > 20 GeVRun range III (run > 172 K)Good runs, hot spots removed
All events
MET > 20
MET > 20, HM > 50
More than ten hot areas!!
7/8/2003 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…
HMatrix Chi2 HMatrix Chi2
Hot EM
Normal EM (same eta)
Hot EM
Normal EM (same eta)
7/8/2003 Yuri Gershtein - CALO Meeting 16
Hadronic Hot Regions Run <162 K, good runs, leading jet, MET>30
7/8/2003 Yuri Gershtein - CALO Meeting 17
Hadronic Hot Regions 162< run<172 K, good runs, leading jet
MET > 30
MET > 50
7/8/2003 Yuri Gershtein - CALO Meeting 18
Hadronic Hot Regions run>172 K, good runs, leading jet, MET>50
7/8/2003 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…
7/8/2003 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