L3 Algorithms: status and plans for the near future

1. L3 Algorithms: status and plans for the near future All-D Meeting: 1st March 2002 Dan Claes and Terry Wyatt.

2. L1 L2 L3 tape 10kHz 1kHz 20-50Hz • L1 L3 tape . 100Hz 20-50Hz • Factor ~ 5 rejection needed • Calorimeter-based filtering (jets, electrons, taus) only • Next steps (p11.02 release): • Improve electron rejection (transverse shower shape) • Commission muons and tracking Design: Curently:

3. Level 3 Jargon • Tool:Does the real work • Unpacks raw data, finds tracks, clusters • Identifies physics objects (e, , , jet ,, W, Z) • Filter:Applies (simple) cuts on objects • e.g. pt() > 10 GeV • Filter Script:Defines a L3 trigger condition • Logical .AND. of one or more filters • If all filters in a script are .TRUE. trigger is satisfied and event is recorded • ‘Mark and Pass’: • Selects unbiassed sample of input events to be recorded • ‘Poor man’s’ efficiency calculation/monitoring

4. L3TJet Tool • author: Volker Buescher(Mainz) • Rejection of L1-accepts makes use of: • high precision calorimeter readout available at L3 • simple cone algorithm • identify (and reject) low-ET events passing L1 trigger • sharpen the turn-on curve • runningonline stably since early Sept’01

5. e.g., Fraction of events passing L3FJet(1,15) DATA runs 142871-142874 pT of leading offline JCCA jet (GeV) • Main effect smearing turn-on is lack of primary vertex at L3 • L3 NADA needed (Marumi Kado investigating) • QCD group: currently adjusting each L3 jet pt cut to value at which the relevant L1 trigger reaches ~ 100% efficiency.

6. L3TEleElectron Tool authors: Volker Buescher(Mainz) Ulla Blumenschein (Mainz) • Current filter: • simple 0.4 cone • applying cuts on • ET • emfrac (>0.9) • providing a rejection of ~3 PrVtx L3TNullVertex()| CAL_CLUS4L3TCalCluster(calunp=CAL_UNP, vertex=PrVtx, conesize=0.4, MinSeedEt=.5)| ELE_LOOSE L3TEle(CAL=CAL_CLUS4,EMFR=0.9)|

7. p11 certification: data runs 142871 - 142874 Fraction of events passing L3Fele(1,5) vs pT of leading offline EM object (GeV) after pre- and standard-selections

8. p11 certification: data runs 142871 - 142874

9. Improvements: 1) Reconstruct EM Object within smaller (0.25) cone L3 Efficiency vs offline EM object pT after pre- and standard-selections ELE_LOOSE L3TEle(CAL=CAL_CLUS4, EMFR=0.9 ConeSize=0.25)| Rejection:

10. Improvements: 2) Additional discrimination available through transverse shower shape cut (shape variables based on an energy-weighted r) , : energy weighted cluster axis position

11. ELE_LOOSE L3TEle(CAL=CAL_CLUS4,EMFR=0.9, ConeSize=0.25, Width_EM1=0.085, Width_EM2=0.085, Width_EM3=0.045)| Zee sample Dr, floor 1 Dr, floor 3 data sample

12. Events rejected by: pt cut e.m. fraction shower shape

13. Triggerlist Proposals (single electron triggers): Lower L3 threshold for inclusive unprescaled EM trigger Replace CEM(1,10)L3FEle(1,15,emfr) with CEM(1,10)L3EM(1,12,emfr,cone=0.25,shape) CEM(1,10)L3EM(1,15,emfr,cone=0.25) Replace CEM(2,5)L3EM(1,10,emfr) with CEM(2,5)L3EM(1,12,emfr,cone=0.25,shape) CEM(2,5)L3EM(1,15,emfr,cone=0.25) Replace CEM(1,5)L3EM(1,5,emfr) with CEM(1,5)L3EM(1,7,emfr,cone=0.25,shape) CEM(1,5)L3EM(1,10,emfr,cone=0.25) Drop prescale? Rejection =10.3

14. L3FTauHadronic Level3 TauTool author: Yann Coadou(Upsala) Running onlinesince 17-Jan-2002 Bug fix to filter installed 09-February p11.01.00 certification included runs over Z QCD MC data run 144102 (>100K events) non-optimized filter currently in triggerlist, gathering information for tuning under online conditions

15. Z + 0 minbias

16. QCD pT>20 GeV

17. Raw Data Run 144102, 104k events

18. L3TMuon responsibles: Martin Wegner(Aachen), Martijn Mulders (Fermilab) (and the L3Muon working group) • Short term goalto filter with L3TMuon • cutting onmuo_localpT • with ‘tight / loose / a-stub’-like quality criteria • Mainly needed for single muon triggers • (which currently have a L1 prescale of ~25)

19. Test Samples p11.01.00 performance/certification Processed following samples • Single 5 GeV Muon MC, <4.2 5000 events • Single 5-100 GeV MC, < 2.5 5000 events • Golden J/psi samples 300 events • Special run 14747 mu1ptaxaa only 19324 events • Recent run 14890 22995 events • No crashes! • Rejection factors >4wrtL1 (loose muons) but p11.01.00 efficiency 50-60% for offline “tight” quality muons Attributed to bugs fixed in p11.02

20. Muon finding efficiency in p11.02 version Low efficiency for ‘tight’ in central region still under investigation

21. Most important outstanding issues: • 1) Memoryleak: • approx. 1.5 kB/event • (probably in the muon segment reconstruction code) • (probably affecting both offline and L3)

22. Memoryleak:

23. Most important outstanding issues: • 2) L3TMuoUnpack (unpacking tool) • Current version requires a configuration file. • When a module is removed from readout, without a corresponding change to the cfg.dat file, • crate data will be ignored creating a hole in L3Muon acceptance • A dynamic unpacker independent of rapidly changing • configuration files (a fix provided by Scott Snyder) • yet to be implemented. • However, we hope to run p11.02 muon code online: • initially a test run, in ‘mark and pass’ mode. • aim for active filtering asap!

24. CFT Unpacking Principal author: Robert Illingworth(IMPERIAL) • Recent improvement (p11.02): • replace global threshold with individual channel thresholds • (as used now in offline reco) • Tested on real data • >89,000 events (Run 146562 17-FEB) • Updating thresholds and cable maps: • requires no code changes • but care in archiving/version-tagging (general problem!) • Daniel Whiteson is studying the improvement this offers • global tracking.

25. Level 3 Global Track Finding author: Daniel Whiteson(BERKELEY) a global (SMT plus CFT) track finder Find axial CFT tracks Match stereo clusters Extend into SMT

26. new unpacking old unpacking Improvement in tracking from new CFT unpacking Beam-spot corrected dca track phi

27. new unpacking old unpacking Improvement in tracking from new CFT unpacking i.e., SMT matching is failing completely! Q/pt q/pt Number of smt hits chisquared Number of tracks

28. CFT Tracking Algorithm - L3TCFTTracker Principal author: Ray Beuselink(IMPERIAL) P11 tool certification:Robert Illingworth and Chris Barnes CFT unpacked and tracked > 27000 assorted MC events (delivered to IC farm by SAM) No crashes, no memory leaks 10,000 events with full (tsim_l3) triggerlist

29. Tracking will not be perfect for a long time. However, our aim is to try and get tracking turned on reasonably soon. For example, add another electron trigger? CEM(1,10)L3EM(1,12,emfr,cone=0.25,shape) CEM(1,10)L3EM(1,12,emfr,cone=0.25,matched_track) CEM(1,10)L3EM(1,15,emfr,cone=0.25) … and similarly for muons? Or run a standalone track trigger at L3 for single muon triggers? N.B. If you don’t like it, you can always exclude it by using the L3 trigger bits.

30. L3 Primary Vertex needed soon! 1) Histogram technique using SMT hits author: Guilherme Lima(UERJ/Brazil) Has yet to be tested on REAL DATA Opportunity for new person to get involved! 2) L3TVertexFinderTrack-based vertexing tool author: Ray Beuselinck(Imperial) Recently upgraded to use either CFTorGlobal candidate tracks as input Per Jonsson(Imperial) testing N.B. Marseille group (Arnaud Duperrin, Mossadek Talby, Eric Kajfasz) will be actively involved in testing tracking, vertexing.

31. Level3 Requirements for certification of Code • Fully tested on a Linux system. • Works "out of the box"(No private mods to code or RCP files) • No crashes/memory leaks on samples of order 100K events: • real data and Monte Carlo. • Timing studies • Performance studies/plots DOCUMENTED • Efficiency, rejection, physics distributions • these tests may run the tool singly,but: • Must run on data with triggerlist exercising all released tools • The filter code must be tested, as well as associated tools. • Must test persistency of physics_results: • Write out events. • Read back in to check physics distributions. • Verification: run trigger simulator on real data and check that results agree with those obtained online. • Shadow nodes (in the future) to test new code ‘online’

32. L3 Monitoring • L3 filter statistics for each trigger available to shift crew via daq_monitor • ‘physics_results’ for each tool written out on each accepted event • debug_info • l3fanalyze program: produces rootuple • Each tool must provide methods to fill rootuple • Used for offline checks of data quality • Plan to run online as ‘examine’ – use root to fill monitoring histograms from rootuple • Extra person needed to work on this! • L3 monitoring needs to get a lot more routine!

33. Conclusions, outlook. • Currently factor ~ 5 rejection needed at L3 • Calorimeter-based filtering (jets, electrons, taus) only • Next steps (p11.02 release): • Improve electron rejection (transverse shower shape) • Commission muons, tracking, primary vertex • Get more systematic monitoring for L3 • When L2 turns on we’ll still need factor ~ 5 rejection at L3, but will have to work harder to achieve it!

34. To find out more: • L3 Algorithms web-pages: http://www-d0.fnal.gov/computing/algorithms/level3/home.html • L3 Algorithms working group meetings take place every on-week, Wednesday 14:00-15:30 in the Farside • Talk to Dan Claes (dclaes@unlhep.unl.edu) or Terry Wyatt (twyatt@fnal.gov) about the opportunities to get involved!