1. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 1 Physics Priorities for Trigger Development Leonard Apanasevich (UIC) Pedrame Bargessa (Rice)

2. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 2 Outline Introduction to the Trigger Development Group Physics priorities during the initial commissioning stage Initial trigger menu planning Start-up Min-Bias Trigger Suite Evolution of the Trigger Menu

3. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 3 Trigger Development Group (i) Rates & Chi-Nahn Ngyuen Menu Compile & Eval. Alessio Ghezzi Simone Gennai Performance Metrics Silvia Lopez PAG Contacts Trigger Menu Development Leonard Apanasevich Pedram Bargassa Prescales Ideas for new triggers come in from PAG’s, POG’s, DPG’s, trigger community. Ensure the resultant global menu fits within the constraints of the L1 and HLT systems. If necessary fine tune thresholds and prescales Provide the tools and expertise to incorporate new trigger paths in the menu Evaluate efficiencies and CPU performance for various luminosity and pileup scenarios For each new trigger:

4. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 4 Trigger Development Group (ii) Provide trigger menus for luminosity/pileup scenarios envisioned during the initial startup stage of the LHC Develop infrastructure needed to allow flexible and rapid development of trigger menus while simultaneously keeping an eye on: –Rates, Efficiencies, and CPU performance Rates & Chi-Nahn Ngyuen Menu Compile & Eval. Alessio Ghezzi Simone Gennai Performance Metrics Silvia Lopez PAG Contacts Trigger Menu Development Leonard Apanasevich Pedram Bargassa Prescales Immediate priority

5. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 5 Physics Priorities for Phase A Calibrate and align the detector; understand the trigger system –Minbias P T and Rapidity Distributions –Jet, J/Ψ, Υ, etc. triggers –Establish MET –Gamma + Jet Calibration Begin to re-establish the Standard Model –Study Jet Angular Distribution, Dijets –Look at standard candles: W, Z, top

6. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 6 LHC Startup Stages Bunches ** IbIb LuminosityEvent rate 1 x 11810 10 27 Low 43 x 43183 x 10 10 3.8 x 10 29 0.05 43 x 4343 x 10 10 1.7 x 10 30 0.21 43 x 4324 x 10 10 6.1 x 10 30 0.76 156 x 15644 x 10 10 1.1 x 10 31 0.38 156 x 15649 x 10 10 5.6 x10 31 1.9 156 x 15629 x 10 10 1.1 x10 32 3.9 Mike Lamont, 20.06.07: Stage A Summary

7. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 7 Simulated L1 rates at 10 28 No thresholds other than noise suppression needed at L = 10 28 -10 29 for all triggers: muons, e/ , jets, missing E T, H T Plot made using 10 million minbias events - no pileup (from S. Dasu)

8. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 8 Initial Trigger Menu Need HLT early on to reduce Level-1 output rate to ~ 200 Hz to tape  Suite of min-bias triggers  Calorimeter low  E T or any muon (no P T cut)  Calorimeter low E T Electron (  5 GeV) or Jet (  10 GeV)  Any muon (effectively  3 GeV P T cut)  Other candidate triggers for later running are active for diagnostic and study purposes Level-1 Trigger Totally Open @ 12.5 kHz

9. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 9 MinBias Trigger Suite Prescaled events in crossings and gaps Minimum total calorimeter E tmin > E noise Single-tower triggers Low threshold L1 "jet" trigger (~10 GeV E t ) –Separate forward jets threshold for HF trigger as well (E tmin (HF) > E noise ) Low threshold Electron trigger (no isolation requirements) HF E T rings (calculated in GCT from RCT sums). Tower over threshold bits in HB/HE/HF Total E T seen in the detector -- this is part of the regular trigger Low threshold Jet trigger – also part of the regular trigger Dedicated scintillators in the forward region (aka OPAL scintillators) -- limited acceptance but used as a check TOTEM detectors if available

10. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 10 Evolution of the Trigger Menu Keep low threshold triggers by adding conditions and/or prescales –Electrons: add isolation at lower thresholds, H/E –Jets: change prescales/add  -bits to preserve thresholds for  ’s. –Muons: add quality conditions at lower thresholds more hits on muon tracks of individual muon trigger systems require coincidence between RPC and either DT or CSC add isolation at lower thresholds Raise thresholds for “unrestricted” triggers –Above lowest possible thresholds do not impose conditions –Calorimeter: no isolation above higher threshold or  -bits –Muon: remove coincidence & isolation, relax hit requirement L1 conditions first validated in HLT, then migrated Employ simultaneous strategies as luminosity & rates rise:

11. CMS Week Sept '07Leonard Apanasevich (UIC) Pedrame Bargassa (Rice) 11 Conclusions The Trigger Development Group has been formed and is working on preparing trigger menus for the initial commissioning stage of the LHC Strategies for trigger development and evolution have be implemented We request input from all corners of the collaboration We are looking forward to the challenges that lie ahead in the upcoming months