L3 Filtering:

- short- and medium term plans

- how you can help out

All-D Meeting:

14th March 2003

Terry Wyatt (FNAL-CD/Manchester)

on behalf of the L3 Algorithms group.

Functions of L3 filter system• Partial event reconstruction• Select which events to be recorded• Define streams • Monitoring

For each L1/L2 trigger that fires:• One or more L3 scripts run• Each script calls the filters/tools necessary for the trigger decision

– performed by ScriptRunner– controlled by the trigger list trigger database

Design rates: @Lumi ~2x1032

L1 L2 L3 tape 5-10kHz 1kHz 50Hz

Time budget for L3 filtering 0.2 s per event

Current rates: @Lumi ~2x1031

L1 L2 L3 tape 1.1kHz 600Hz 50Hz

Currently running online (global_CMT-10.35)

cal unpack cal.cluster electron tau jet acoplanarity Ht

missing Et

smt unpack global tracker primary vertex (z)

cft unpack

muon unpack local muon track-matched muon

(+ geometry tool)

Other infrastructure

• L3 streaming infrastructure essentially ready• L3 filter statistics for each trigger available to

shift crew via daq_monitor• L3 trigger examine

– runs on rootuple produced by l3fanalyze

• L3 physics_results stored on TMB– YOUR physics analysis can become part of routine

monitoring of L3!

Using primary vertex z to improve jet Et resolution (Andy Haas)

significantly sharper turn on curve with L3 primary vertex

New Features for p15

• gcc compiler• primary vertex filter (z)• 3D primary vertex finder• input run-by-run beam spot

• pt-dependent track dca errors

• tools to produce L3 physics_results

(start to decouple TMB analysis from L3 algorithm code)

needed for impact

parameter-based

b-tag

Primary vertex filter (Andy Haas)

• L3 primary vertexing in z– 98 % efficient (relative to offline)– Agrees with the offline best vertex– Sigma is 0.36 cm in z

• Can filter on:– z of the primary vertex– number of tracks in the primary vertex

• Possible use – select events within SMT acceptance

25% of events have |Z| > 35cm

~1% of eventswith >=3 b-tagshave |Z| > 35cm

bbH MCjet data

3D primary vertex finder (Chris Barnes)

• Select tracks consistent with:– primary vertex in z– run-by-run beam spot in xy

• Remove tracks with large

Run-by-run beam spot

vertex_examine

BeamSpotMonitor ACNET

COOR

L3 Supervisor

ScriptRunner

L3 Tools

Michiel Sanders

Scott Snyder

Gordon Watts

Jon Hays

L2STTRuns DB

same mechanism canbe used for other L3logging/configurationtasks

Beam spot drift from vertex_examine

• stable over long periods of time

• position/tilt from previous run/store would usually be good enough

• precise running strategy still to be worked out

50 mx

y

(Michiel Sanders)

Impact parameter based b-tag (Per Jonsson)

p15 status

• Aim to get p15 online within about a month of p15 cut

• A lot of preparatory work done in test release (Angela Bellavance)– gcc required a large number of packages to be fixed

• l3fanalyze rootuples produced with t03.07.00 trigsim for data taken online with p13 and global_CMT-10 (Angela Bellavance, Han Do)– performance tests of global_CMT-10 tools underway

• commissioning the p15 new features may take a little longer

Aims for p16 (June 2003)

• CPS (Yi Jiang, Andre Turcot)• Improve tracking efficiency/resolution (Arizona/I.C.)• Extend tracking beyond 1.5 (Arizona)• Muons: (Martin Wegner)

– track + calorimeter muon id.– di-muon filters

• Refined treatment of electron shower shape (Ulla Blumenschein)

• FPD (Tamsin Edwards)• FPS ?

Other activities

• Code management (Angela Bellavance, Jon Hays)• On-/Off-line comparator (Han Do)• L3 section of MC trigger list (Terry Toole, Terry

Wyatt)• Identification of physics event types using L3

objects:– J/ (Ike Hall)– Z (Emily Nurse, Terry Wyatt)

• routine offline efficiency monitoring• online event flagging

Extra help needed urgently!

- E.g., Calorimeter tools `orphaned’

• electron, tau, jet, missing Et need study of:

– primary vertex z to improve Et resolution

– calorimeter non-linearity corrections – central track match– influence of L3nada– influence of coarse hadronic layer– other quality cuts?

• software tools exist• need people willing to run Trigsim and look at the resulting

rootuple!

– recent volunteers: Cristina Galea, Luiz Mundim

- E.g., matching L3 objects to MC/L1/L2/reco objects

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?

To find out more:

• L3 Algorithms web-pages:http://www-d0.fnal.gov/computing/algorithms/level3/home.html http://www-d0.fnal.gov/computing/algorithms/level3/status.htmlhttp://www-d0.fnal.gov/computing/algorithms/level3/projects.html

• L3 Algorithms working group meetings take place every week: Wednesday 14:00-15:30 in the Farside

• Talk to Dan Claes (dclaes@unlhep.unl.edu), Terry Wyatt (twyatt@fnal.gov) or Rick Jesik (jesik@fnal.gov) about the opportunities to get

involved!