single top trigger studies top trigger meeting, 9 may 2007 - 1 patrick ryan, msu single top trigger...
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Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 1Patrick Ryan, MSU
Single Top Trigger Studies
Top Trigger Meeting
9 May 2007
Patrick Ryan
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 2Patrick Ryan, MSU
Level 1 Muon Trigger
• Level 1 Muon Triggers Exclusive in Version 12• Only one trigger fires for each muon
• MU06 only accepts events between 6 and 8 GeV• MU08 only accepts events between 8 and 10 GeV
• Muon triggers will be inclusive in Version 13
• Muon Trigger Flags• Each trigger has single Integer flag for each event• 2 muon candidates can fire 2 separate muon triggers
• An event can have both MU06 and MU08 fired• Muon trigger can fire even if event has 0 truth muons
• Muons not coming from W with pT < 5 GeV (not stored in Truth tree)• Muons not originating at vertex• Punch-throughs• Want to investigate these events to make sure we understand them
• See following slides
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 3Patrick Ryan, MSU
Truth Information in TopView
• Truth0 Tree• All muons from W decay
• Other muons (from jets & punchthu only if pT > 5 GeV)
• TruthAll Tree• All muons regardless of pT
• Need all muons to compare to muon trigger efficiency• Large and slow
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 4Patrick Ryan, MSU
Muons Triggers
• Ran over 56250 total events (5200 Sample)• Lower threshold triggers accept more events with 0 muons
• Muons with pT < 5 GeV can fire triggers (fake rate)• Becomes less likely for higher trigger pT thresholds
Trigger Passed 0 Truth Muons 0 TruthAll Muons
MU06 1723 407 (23.6%) 162 (9.4%)
MU08 1293 164 (12.7%) 87 (6.7%)
MU10 3338 363 (10.9%)
MU11 3623 109 (3.0%)
MU20 3911 52 (1.3%)
MU40 17017 59 (0.3%)
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 5Patrick Ryan, MSU
MU06 and 0 Truth Muons
• Plot TruthAll muons• 1723 of 56250 total events total events passed MU06• 407 of 1723 events had 0 Truth Muons (left plot)• All TruthAll muons in events with 0 Truth muons have pT < 5 GeV
• Confirms that these muons come from somewhere other than vertex
407 events having 0 Truth Muons
All muons in all events with 0 Truth Muons
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 6Patrick Ryan, MSU
MU06 and 0 TruthAll Muons
• 162 of 407 events with 0 Truth also had 0 TruthAll muons• Multiplicity distributions of trigger sample shifted slightly to right
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 7Patrick Ryan, MSU
MU06 and 0 TruthAll Muons
• Higher statistics sample for pT and eta distributions• Trigger sample slightly lower at low pT and higer at high pT
• Trigger sample slightly higher around eta = 0.
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 8Patrick Ryan, MSU
MU06 and 0 TruthAll Muons
• Where do events with 0 TruthAll Muons come from?• Muon LV1 triggers only on muons originating at vertex• Possibilities of non-vertex muons include
• Muons from jets• Muons from punch-throughs
• Check LV1 Muon trigger rates for muons from jets and punch-throughs• Alessandro DiMattia working on this
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 9Patrick Ryan, MSU
Single Top Muon Efficiencies
• TopView Version 1212 MuidTauRec 003 ntuples• Truth efficiencies
• No selection cuts• Ratio of number of events before and after trigger
• Reconstructed efficiencies• Apply common single top event selection
• At least 1 high-pT lepton (e or )• Electron pT > 25 GeV• Muon pT > 20 GeV
• No secondary lepton with both pT > 10 GeV and -1.475 < < 1.475• Njet ≥ 2
• pT1 > 30 GeV
• pT2 > 25 GeV
• NJetB-tagged ≥ 1 where b-tagged jet has pT > 35 GeV
• ETMiss > 25 GeV
• Ratio before and after trigger calculated after event selection
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 10Patrick Ryan, MSU
Muon Efficiencies 5200 (ttbar) Sample
• Compare to ttbar group study (Attila’s latest T5 talk page 4)• Calculated efficiencies using 2 methods
• Wrong: (MU06 + MU08 + … + MU40) / Total• Overcounts since a single event can have two muons triggers fired
• Right: (MU06 || MU08 || … || MU40) / Total (shown above)
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 11Patrick Ryan, MSU
Muon Efficiencies 5500 (Wt) Sample
• Truth and reconstructed efficiencies have same shape• Reconstructed efficiency about 15% higher than truth efficiency
• We expected reconstructed efficiency to be even higher (around 90%)
• About 8% efficiency change between MU06 and MU40• Highest efficiency of the single top channels
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 12Patrick Ryan, MSU
Muon Efficiencies 5501 (s-channel) Sample
• Truth and reconstructed efficiencies have same shape• Reconstructed efficiency about 25% higher than truth efficiency
• We expected reconstructed efficiency to be even higher (around 90%)
• About 10% efficiency change between MU06 and MU40• Lowest effiency of the single top channels
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 13Patrick Ryan, MSU
Muon Efficiencies 5202 (t-channel) Sample
• Truth and reconstructed efficiencies have same shape• Reconstructed efficiency about 20% higher than truth efficiency
• We expected reconstructed efficiency to be even higher (around 90%)
• About 10% efficiency change between MU06 and MU40
Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 14Patrick Ryan, MSU
Plans
• Finish LV1 Muon study
• Efficiencies for e, jets, etc.
• Efficiencies at Level 2 and Event Filter