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H FTK update. Catalin, Tony FTK meeting, 9/7/2006. Recap: H with FTK. Step1: look at LVL1 side Step2: look at LVL2 side Similar to Kohei’s study. LVL1 (+new trigger). LVL2 (+FTK). 200 Hz. 40 kHz. Recap: EM and tau at LVL1. Definition of EM: L1Em_EmClus > threshold &&
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H FTK update Catalin, Tony FTK meeting, 9/7/2006
Recap: H with FTK • Step1: look at LVL1 side • Step2: look at LVL2 side • Similar to Kohei’s study LVL1 (+new trigger) LVL2 (+FTK) 200 Hz 40 kHz
Recap: EM and tau at LVL1 • Definition of EM: • L1Em_EmClus > threshold && • L1EmIsol < 4 GeV && • L1Em_HdIsol+L1Em_HdCore < 2 GeV • Definition of : • L1Em_TauClus > threshold && • L1EmIsol < 4 GeV && • L1Em_HdIsol < 2 GeV tau electron Had sum<2 GeV EM isolation<4 GeV
LVL1 EM and tau dijet rates • Eric and Alan pointed us to the latest dijet study by Pilar Casado (IFAE, Barcelona): • https://twiki.cern.ch/twiki/bin/view/Atlas/LVL1TauStudies • LVL1 trigger rates are given for 10^31 for various thresholds • L1em_EmClus>9GeV && L1EmIsol<4GeV: 1.6 kHz (we: 1.4kHz) • L1em_TauClus>9GeV && L1EmIsol<4GeV: 2.8 kHz (we: 2.3kHz) • Different cross-sections could account for this 13% and 18% diff. • Only J1 and J2 samples contribute significantly to the rates: • EM trig: J1,J2,J3,(J4+…+J8) ~ 81%, 18%, 1%, <0.06% • TAU trig: J1,J2,J3,(J4+…+J8) ~ 83%, 16%, 1%, <0.05%
LVL1 trigger study • According to Alan Watson: • LVL1 trigger decision based on multiplicities alone (does not use any roi info at LVL1) • Run over dijet and keep track of the following: • Isolated EM cluster count: EM • Isolated TAU cluster count (could be the same as above): EM-had • Isolated TAU cluster different from EM count: !EM • (EM-had, EM-had) pair count • (!EM, !EM) pair count • (EM+2 EM-had) count • (EM+1 !EM) count
LVL1 Trigger Rates at 2*1033 cm-2s-1 • 1EM (black) up to 300 kHz • 1EM-had (red) up to 150 kHz • LVL1 projected 40 kHz, designed max output 75 kHz
EM+ LVL1 trigger rate at 2*1033 • EM+>1EM-had rate up to 10 kHz • Shown versus EM-threshold or threshold • Stronger dependence on threshold than on EM threshold
2 LVL1 trigger rate at 2*1033 • Require 2EM-had objects • Rate up to 20 kHz
2!EM LVL1 trigger rate at 2*1033 • Not possible to trigger on, but interesting • As much as 3kHz comes from 2 hadronic taus • Could be interesting to study if and how much increases signal acceptance in the all-had channel
Step2 – LVL2 rejection • Thanks to Paola for pointing us to the CMS algorithm Jet axis leading PT track RS RI RO Recipe: - find leading PT track in a RI=0.1 cone around the jet - require PT(lead. track) > 3 GeV - find tracks within an RS=0.07 cone around lead. - count, as before, tracks in the isolation reg: RS<R<RO
Higgs 130 GeV Curves correspond to different RO & min leading PT . RS=0.07, RI=0.1 for all. RO=0.3, PTSig>3.0 GeV/c factor of ~1.4 optimum RO=0.5, PTSig>10.0 GeV/c Max tracks in,out 3,1 2,2 2,1 4,0 3,0 1,2 1,1 2,0 1,0 “in” tracks are here w/ Pt>1.0 “out” tracks are here w/ Pt>0.5
Sherpa Dijet RO=0.3, PTSig>3.0 GeV/c factor of ~10 RO=0.5, PTSig>10.0 GeV/c Curves correspond to different RO & min leading PT . RS=0.07, RI=0.1 for all. Max tracks in,out 3,1 2,2 2,1 4,0 3,0 1,2 1,1 2,0 1,0 “in” tracks are here w/ Pt>1.0 “out” tracks are here w/ Pt>0.5
Conclusions and Outlook • We believe we have the correct LVL1 trigger implementation, and we verified that we can reproduce some recent dijet trigger rates to within 10-20% • At LVL2 we can dial dijet rejections corresp to factors of 5-100. • Questions are: • How much is it admissible to increase the LVL1 or LVL2 output rates? • Which of the above limits us? • For example, we can add EM+tau trigger with thresholds 10-25 GeV which would increase the LVL1 output rate by <10 kHz • Remains to be investigated: • How much signal we gain • If we would gain significantly in the hadronic ditau Higgs channel
Recap: Trigger Study – May 06 Lepton ET LOW-LUM HIGH-LUM 10,15,20 0 MU20 (20) 2MU6 1 EM25I (30) 2EM15I (20) 2 J200 (290) 3 3J90 (130) 4 4J65 (90) 5 J60+xE60 (100+100) 6 TAU25+xE30 (60+60) MU10+EM15I Missing ET Tau ET 15,20,25,30 10,15,20,25
Recap: Low Luminosity RegimeSignal: 130 GeV H met>15 met>30 Trigger efficiency ET() threshold ET() threshold ET() threshold ET(lep) > 10 GeV ET(lep) > 15 GeV ET(lep) > 20 GeV Reminder: - only lepton, tau, and met thresholds are varied - rest of the trigger table stays the same Biggest effect: lowering the lepton ET threshold (up to 15% gain)
More Backup • 1!EM rates vs EM or thresholds (at L=2*1033) • Stronger dependence on threshold