1. UPDATE First Look at Trigger Efficiencies from AOD for ttH, H  bb Catrin Bernius UCL ATLAS Physics Meeting 12.10.2007

2. 2 Some Info about Trigger Menus for semileptonic ttH For semileptonic ttH channel (Ricardo's talk, Trigger Menu Workshop, Sept 2007):Ricardo's talk –trigger on high pT isolated letpon (from W): mu20i and e25i –B tagging triggers also useful (Fabrizio‘s talk, Trigger Menu Workshop, Sept 2007) –e25i_xeNN, e25i_jMM or e25i_teKK: with aim of lowering lepton threshold (& same for muons?) needs to be studied Trigger Information from AOD provided by TriggerDecision Problems in rel 12.0.6 for electron and muon trigger: –Muons: only the highest L1 muon threshold fired –e.g.: event with 50GeV muon, L1_MU40 fired (nearest threshold), but L1_MU08, L1_MU10 etc. not passed. –To get correct trigger decision, all higher thresholds need to be checked Isolation is currently not implemented for muons in release 13 –Electrons: level 2 spacepoint bug (FIXED IN RELEASE 13) Problem in reconstruction where tracks aren‘t formed at L2 due to missing code Leads to non-flat efficiencies in eta at L2 Can only be fixed by re-reconstruction from RDO‘s http://indico.cern.ch/getFile.py/access?contribId=52&sessionId=4&resId=0&materialId=slides& confId=16155 (slide 5)http://indico.cern.ch/getFile.py/access?contribId=52&sessionId=4&resId=0&materialId=slides& confId=16155 TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU06 did not pass TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU08 did not pass TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU10 did not pass TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU11 is fulfilled TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU20 did not pass TriggerDecision... INFO TriggerDecision: L1 Trigger Item L1_MU40 did not pass

3. 3 Datasets datasets used for this study: signal sample with 39000 events generated with Pythia –trig1_misal1_mc12_V1_005870.ttH_poslepnu_jj_bb.recon.AOD.v12000601_tid008657 –trig1_misal1_mc12_V1_005871.ttH_neglepnu_jj_bb.recon.AOD.v12000601_tid008658 Generator cuts on lepton: –pT > 10 GeV –|  | < 2.7 GeV

4. 4 e25i Trigger Efficiency vs p T truth,  truth LVL 1 LVL2 EF Spacepoint bug: non flat efficiencies at L2 BEFORE ttH RECONSTRUCTION

5. 5 mu20 Trigger Efficiency vs p T truth,  truth LVL 1 LVL2 EF BEFORE ttH RECONSTRUCTION

6. 6 e25i Trigger Efficiency vs p T truth,  truth LVL 1 LVL2EF AFTER ttH RECONSTRUCTION

7. 7 mu20 Trigger Efficiency vs p T truth,  truth LVL 1 LVL2 EF AFTER ttH RECONSTRUCTION gap in muon detector

8. 8 Some numbers... Before ttH Reconstruction After ttH Reconstruction  (lep)  (e)  (  )  (lep)  (e)  (  ) L1 74% 75% 74% 85% 93% 78% L2 67% 63% 70% 81% 83% 76% EF 61% 55% 66% 76% 76% 76%  (lep) = (#e+muons which pass e25i/mu20) / (#e+muons from W)  (e) = (#e which pass e25i) / (#e from W)  (  ) = (#muons which pass mu20) / (#muons from W)

9. 9 More numbers...  (lep) = (e25i or mu20) / (# higgs candidates)  (e) = (e25i) / (# higgs candidates)  (mu) = (mu20) / (# higgs candidates) After ttH Reconstruction  (lep)  (e)  (  ) L1 87% 38% 49% L2 83% 37% 46% EF 79% 35% 43%

10. 10 Eta distribution for muons (EF) gap in muon detector due to cryostat of LAr

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