1. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 1 Patrick Ryan, MSU Single Top Trigger Studies Top Trigger Meeting 21 May 2007 Patrick Ryan

2. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 2 Patrick Ryan, MSU Events with No TruthAll Muons Events with no TruthAll Muons trigger L1 MU TopView Ntuples TruthAll tree - all muons Truth tree All muons from W decay Other muons included only if p T > 5 GeV What causes the trigger to fire Muons not originating at vertex Jets interacting with calorimeter In-flight decays Bug in software

3. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 3 Patrick Ryan, MSU Investigation of Events with No TruthAll Muons Distance between LV1 Trigger and Jets Just received TopView ntuples with trigger info Currently investigating Muon Track Record in ESD/AOD Contains info about all muons in muon system Involves complicated study of ESD/AOD Removal of these events by LV2 Run over 56,250 events (162 have 0 TruthAll Muons & Pass MU06) Isolation cut removes all (hints that events come from jets) L1L2Pass L1Pass L2 MU06mu0616224 MU06mu06l162124 MU06mu20i1620

4. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 4 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

5. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 5 Patrick Ryan, MSU Muon Efficiencies 5500 (Wt) Sample Efficiencies after reconstructed efficiency Last week (left plot): required electron OR muon in event selection Causes low efficiency if only muon trigger is used Currently (right plot): require a Muon Efficiency after event selection is about 90% as expected Will separate electron and muon analyses for future studies Old Current

6. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 6 Patrick Ryan, MSU Muon Efficiencies s and t Channel Efficiencies range from 80 to 95% as expected s channel T channel

7. Single Top Trigger Studies Top Trigger Meeting, 21 May 2007 - 7 Patrick Ryan, MSU Plans Investigate LV1 Muons at AOD level Continue Level 2 studies Efficiencies at Event Filter Efficiencies for e, jets, etc.