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B-Trigger Working Group Work-plan

John Baines. B-Trigger Working Group Work-plan. Contents: Updates since the TP (as shown at last meeting) New resource estimates RoI guided B-trigger Future Work Summary. This talk: http://hepunx.rl.ac.uk/atlasuk/simulation/level2/meetings/pesa290502/B-trigger-status.ppt

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B-Trigger Working Group Work-plan

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  1. John Baines B-Trigger Working GroupWork-plan • Contents: • Updates since the TP (as shown at last meeting) • New resource estimates • RoI guided B-trigger • Future Work • Summary This talk: http://hepunx.rl.ac.uk/atlasuk/simulation/level2/meetings/pesa290502/B-trigger-status.ppt http://hepunx.rl.ac.uk/atlasuk/simulation/level2/meetings/pesa290502/ B-trigger-status.ps http://hepunx.rl.ac.uk/atlasuk/simulation/level2/meetings/pesa290502/ B-trigger-status.pdf

  2. Benchmarking & Resource Estimates Preliminary paper model results (April 2002): Final Farm size Difference ~25 c.p.u Min. size incl. B-physics Min. Farm size needed at startup • Note: • Most B-trigger resources required for LVL2 full-scan • In order to save cpu resources, not using TRT info at LVL2: • => No J/psi(e,e) trigger • Resources required at EF small compared with LVL2 (~few cpu) assuming: • xKalman starting with pixels and guided by Level-2 RoI • (see presentation at previous meeting) • neglecting resources needed for muon reconstruction at EF • Current offline muon algorithms too costly in cpu : • => Only includes muons at LVL2 reconstructed by mFast B-trigger resource estimate: ATL-COM-DAQ-2002-013

  3. Using Calorimeter RoI to guide B-physics Triggers • Preliminary studies of using low ET RoI to define regions to search ID at LVL2(Alan Watson) • Uses fast simulation : • ATLFAST + parameterised calorimeter simulation • Initial results encouraging,see Alan Watson’s talk:http://www.ep.ph.bham.ac.uk/user/atw/bmeet/B-roi-feb02.ppt • EM RoI ET>2 :for J/y(ee) and muon-electron triggers • Mean Multiplicity = 1.1 (B->mX , m pT > 6 GeV) • Effic. to tag both e in J/y(e,e) : 80% (e pT >3 GeV) • Jet RoI (0.8 x 0.8 cluster) ET>5 :for B(pp) and Ds(fp) • Mean Multiplicity = 1.7 (B->mX, m pT > 6 GeV) • Efficiency • B p p • pTp> 4 GeV • RoI ET> 5 GeV • B Dsf • pT Ds, f> 1 GeV • RoI ET> 5 GeV • LVL2 reconstruction inside RoI • potential to save ~factor 10 in execution time c.f. full-scan • but with lower efficiency Actual efficiencies and cpu savings depend on thresholds & multiplicities => need full simulation

  4. Future Work • Calorimeter RoI guidance for B-triggers: • In RoI guided scheme, the main factors driving resource requirements are: • muon trigger rate & muon algorithm time • Jet RoI multiplicity, Jet RoI Size, time for ID reconstruction in Jet RoI • => Important to confirm RoI multiplicities with full simulation • => Need full simulation to determine trigger efficiency • Requires : • Simulation of: • Level-1 EM/Tau trigger algorithm - done (Ed Moyse) • Level-1 Jet trigger algorithm - underway (Ed Moyse) • Level-1 electronics (noise) - who? • Generation of simulated data : • single particles for calibration • B->mX events • signal channels : B->pp, B->J/y(ee), B->Ds(f(KK)p) • min. bias • Addition of pile-up (including pulse history in ECAL). • Calibration of ECAL energies (electron work-group) • Level-1 studies - Optimisation of thresholds (Level-1 work-group)

  5. Future Work – contd. • Requires: • New datasets (including pile-up) • Algorithms able to read new datasets (LVL2 & EF) Verification / optimisation of LVL2 & EF algorithms with latest layout : Timing measurements for complete chain: • Requires: • Byte-stream data for all detectors. • Convertors for all detectors • Optimized algorithms – LVL2 & EF • B-trigger studies including muon trigger: • Confirm previous results (Kine muon) • Study di-muon trigger – thresholds, rates • Requires: • New datasets including muon simulation • Muon algorithms available in new framework (LVL2 & EF, barrel & end-cap) • Event Filter Selection: • Study B->mm(X) selections • Study using LVL2 to guide EF • Requires: • EF algorithms • RoI guidance mechanism for EF

  6. Summary • A lot of work to do, time-scale very tight (even following postponement of TDR) • Priorities are : • LVL1 guidance to LVL2 B-trigger: • di-muon trigger • Low ET Jet Trigger • Low ET Electron trigger • LVL2 guidance to EF • Updates with new geometry. • EF selection for B->mm(X) • A lot of work is on hold awaiting new data and software. • Little incentive for algorithm development whilst framework and interfaces are still evolving. • People have drifted away from B-trigger working group to other things. • Currently probably less than one Full Time Equivalent working on B-trigger! • Need to attract people back by providing: • a well defined programme of work • a stable set of tools.

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