1. L3 Filtering: status and plans D  Computing Review Meeting: 9 th May 2002 Terry Wyatt, on behalf of the L3 Algorithms group. For more details of current status of individual tools/filters see, e.g., L3 talk at trigger workshop: http://www-d0.fnal.gov/computing/algorithms/level/docs/L3_workshop.ppt

2. Design rates: L1 L2 L3 tape 10kHz 1kHz 20-50Hz Functions of L3 system: Event building (not discussed further here) Filtering: Partial event reconstruction Select which events to be recorded Define streams Monitoring L3 farm has 100 x 1 GHz P3 CPUs Time budget for L3 i/o, event building, filtering  100/1000 = 0.1 s

3. Within weeks : L1 L2 L3 tape 500 Hz 30-40Hz Currently: L1 L3 tape. 100 Hz 20-30 Hz Factor ~ 5 rejection needed Calorimeter-based filtering only (jets, electrons, taus) Next steps (p11.06, p11.07 releases) to commission: Muons, global tracking, track-based primary vertexing. “Offline” quality geometry and unpacking for tracking and calorimeter. and we shall have a much better idea of how much cpu is needed for filtering

4. For each L1/L2 trigger that fires: One or more L3 filter scripts run Each script calls the filters/tools necessary for the trigger decision Details of: which scripts called for each L1/L2 trigger which filters/tools are called by each script –performed by ScriptRunner –determined by the triggerlist database

5. Other tools in development cft-only tracking missing E T tools to associate objects in different detectors (e.g. track to muon) cps and fps cluster finding and unpacking b-tag: impact parameter, secondary vertex tools to calculate "physics" quantities –(e.g., inv. mass, delta_eta) tools to identify physics event types –(e.g., W, Z, stream definitions) Standard certification and verification requirements: http://www-d0.fnal.gov/computing/algorithms/level3/meetings/talks/certification.html

6. L3 Monitoring Now L3 filter statistics for each trigger available to shift crew via daq_monitor L3 reconstruction results written out with the raw data l3fanalyze program: produces rootuple –Used offline for: testing new code versions checks of data quality

7. L3 Monitoring Needed A lot more work to do here! –implement shadow nodes –run l3fanalyze online as ‘examine’ fill monitoring histograms from rootuple –macros to define/display monitoring histograms –common job submission on standard test samples to exercise all the L3 tools/filters migration to online –"bit-wise" on/offline check –matching L3 objects to MC/L1/L2/reco objects Try to pool efforts as much as possible with other groups, especially L2.

8. Extra manpower needed for L3 central infrastructure Scriptrunner + central L3 code infrastructure, release management 1.5 Streaming0.5 Monitoring1.5 Calibration/alignment technical infrastructure1.0 Development of "user" and "physics analysis" tools>1 L3 thumbnail0.5 + a lot of work to develop and test L3 tools and filters and work out how best to use them for physics!

9. There are many open questions How to handle redundancy in trigger, e.g., leptons –many L3 filter scripts –one L3 filter script (with details stored in L3 data) Are 256 L3 triggers enough? What else can we do in L3? –more sophisticated monitoring? –technical and/or physics measurements on rejected events? –define “not for reco” stream?

10. Trigger Simulation Level 1 “hardware” trigger requires full simulation Level 2 Level 3 “software” trigger (C++ code) run same software online and in simulator run on raw data or Monte Carlo algorithm development efficiency/rejection estimates technical software checks – e.g. memory/cpu consumption

11. Level 2 Simulator The currently available L2 preprocessors are: calorimeter jet calorimeter electromagnetic tested muon central on data muon forward calorimeter missing Et central preshower central track trigger (silicon + fibre tracker) (STT soon to be integrated) + L2 global essentially complete

12. Trigger List Trigger Database.xml file COOR COORSIM download D0TrigSim online RawDataChunk Monte Carlo Datafile (d0sim)

13. Manpower Requirements TopicNumber of FTE required D0TrigSim executable1 L1 subsystems + coordination 3 L2 simulation2 L2 offline verification + analysis tools 1