1. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 1 Patrick Ryan, MSU Single Top Trigger Studies Top Trigger Meeting 9 May 2007 Patrick Ryan

2. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 2 Patrick 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 p T < 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

3. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 3 Patrick Ryan, MSU Truth Information in TopView Truth0 Tree All muons from W decay Other muons (from jets & punchthu only if p T > 5 GeV) TruthAll Tree All muons regardless of p T Need all muons to compare to muon trigger efficiency Large and slow

4. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 4 Patrick Ryan, MSU Muons Triggers Ran over 56250 total events (5200 Sample) Lower threshold triggers accept more events with 0 muons Muons with p T < 5 GeV can fire triggers (fake rate) Becomes less likely for higher trigger p T thresholds TriggerPassed0 Truth Muons0 TruthAll Muons MU061723407 (23.6%)162 (9.4%) MU081293164 (12.7%)87 (6.7%) MU103338363 (10.9%) MU113623109 (3.0%) MU20391152 (1.3%) MU401701759 (0.3%)

5. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 5 Patrick 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 p T < 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

6. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 6 Patrick 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

7. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 7 Patrick Ryan, MSU MU06 and 0 TruthAll Muons Higher statistics sample for p T and eta distributions Trigger sample slightly lower at low p T and higer at high p T Trigger sample slightly higher around eta = 0.

8. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 8 Patrick 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

9. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 9 Patrick 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-p T lepton (e or  ) Electron p T > 25 GeV Muon p T > 20 GeV No secondary lepton with both p T > 10 GeV and -1.475 <  < 1.475 N jet ≥ 2 p T 1 > 30 GeV p T 2 > 25 GeV N Jet B-tagged ≥ 1 where b-tagged jet has p T > 35 GeV E T Miss > 25 GeV Ratio before and after trigger calculated after event selection

10. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 10 Patrick 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)

11. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 11 Patrick 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

12. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 12 Patrick 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

13. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 13 Patrick 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

14. Single Top Trigger Studies Top Trigger Meeting, 9 May 2007 - 14 Patrick Ryan, MSU Plans Finish LV1 Muon study Efficiencies for e, jets, etc. Efficiencies at Level 2 and Event Filter