L3 Filtering: status and plans

D Computing Review Meeting:

9th 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

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 CPUsTime budget for L3 i/o, event building, filtering 100/1000 = 0.1 s

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

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

Other tools in development

• cft-only tracking• missing ET

• 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

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

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.

Extra manpower needed for L3 central infrastructure

Scriptrunner + central L3 code infrastructure, release management

1.5

Streaming 0.5

Monitoring 1.5

Calibration/alignment technical infrastructure 1.0

Development of "user" and "physics analysis" tools >1

L3 thumbnail 0.5

+ a lot of work to develop and test L3 tools and filters and work out how best to use them for physics!

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?

Trigger Simulation

Level 1“hardware”

triggerrequires 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

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

Trigger List

Trigger Database

.xml file

COOR COORSIM

download D0TrigSim online

RawDataChunk

Monte Carlo Datafile(d0sim)

Manpower Requirements

Topic Number of FTE required

D0TrigSim executable 1

L1 subsystems + coordination

3

L2 simulation 2

L2 offline verification +

analysis tools

1