L3 MUONS


Run IIb plots.

Algorithm

The Level 3 muon code is identical to the reco muon code, albeit with different rcp settings (fewer combinations of segments and fewer fitting iterations) due to the time constraints at Level 3. For more information, please refer to the reco muon webpage and the links listed below.

Resolutions and Turn-on curves for Level 3 muons wrt to reco muons can be found in the p17 certification note 4887.

The Level 3 muon filter (l3filters/src/L3FMuon.cpp) uses the following trigger list parameters (in this order!):
refset (tool): Muon tool used to find muon candidates.
Either 'Muon' (local muons only) or 'MUON_CM' (attempt track match, but retain unmatched candidates).
number (int): Number of muons required in the trigger to pass.
MinEt (float): Not used. Please set to 0.
MinEta (float): Minimum eta for muon candidates. Usually set to 0.
MaxEta float: Maximum eta for muon candidates. Usually set to 2.5.
MinPhi float: Minimum phi for muon candidates. Usually set to 0.
MaxPhi float: Maximum phi for muon candidates. Usually set to 6.29.
MinPtLocal float: Minimum local pT (set to 0, when requiring track matched muons).
MinPtCentr float: Minimum pT for track matched muons (pT used is from central track, not local muon.)
MinQuality string: ASTUB, LOOSE, MEDIUM, TIGHT (case sensitive!)
CalMatchReq (bool): Calorimeter matching was never implemented. This parameter has to be set to FALSE.
CentralMatchReq (bool): TRUE or FALSE: Note that this condition applies to all muons, i.e. one instance of the filter can only deal with local *or* track matched muons.


(Main) Packages
l3fmuo_unpack: The unpacker. As far as I can tell it works fine (and fast), so I tend to leave it well alone.
l3fmuo_local: Calls segment and track finding. Determines quality of the muon.
l3fmuo_centralmatch: Matches muon-system-only muons to central tracks. Central tracks are required to have at least 10 axial hits (no stereo hit requirement). This tool currently calls the global tracker with a hard wired pT cut of 1.5 GeV.
l3fMuonTools: fills L3MuonPhysicsresults using results from l3fmuo_local and l3fmuo_centralmatch to be used by the filter.
l3fMuonTools_results: Home of the L3MuonPhysicsresults.
l3filters: class L3FMuon is called by the trigger and returns pass/fail depending on whether the trigger conditions were met or not.
l3fmuo_caltrack: for calorimeter muons, not used.
l3fmuo_calmatch: for calorimeter muons, not used. Nobody has looked at the last two packages in years, I have *no* idea what is going on here.



p19 (RunIIb) certification

News: The track quality for track matched muons is now a trigger list parameter:
  standard: This is used as default if no parameter is given. Requires 10 axial hits per track, i.e. this is the old p17 definition.
  loose: 8 axial hits
  looseSMT: 8 axial hits, two of which must be in the SMT
  medium: 10 axial hits, two stereo SMT hits
  tight: 10 axial hits, two stereo SMT, two stereo CFT hits


p17 certification

The certification has ended. It's still not pretty, but at least it's faster now. The results are summarized in D0 Note 4887.


p16 certification

p16 certification work page

Content of the L3 Muon trigsim_analyze root-tuple. (Obsolete for higher releases.)

Write-up of p16 certification (ps files): D0 Note 4470.


How to ...?

How to run reco and keep the raw data chunk.

How to compare L3 and Reco information.

How do I access L3 muon information ? Examples can be found in the l3muo_cert package.

How to find out which parameters a tool/filter uses ? Look in trigdb_scripts/rcp/tools.rcp or filter.rcp.


D0 Notes relevant for L3 Muons:

The old L3 Muon page.

Unfortunately some of these notes have been written in Word (?!) and the conversion to ps/pdf didn't always work. Please use PostScript.

D0 Note 3992, C. Clément, S. Snyder, The Level 3 Muon unpacker (Note)

D0 Note 4436, C. Auterman, The Level 3 isolation tool, (Note)

D0 Note 3999, Balm, Clément, Diehl, Mulders, Söldner-Rembold, Wegner, The D0 Level-3 muon filter (Note)

D0 Note 3934, P. Balm, Central Track Matching of Muon Track at Level 3 (Note)

D0 Note 3901, O. Peters, Muon Segment Reconstruction - Linked List Algorithm (Note)

The only documentation I could find on the fitting algorithm (by Frédéric Déliot).

An old (April 2001) but still quite instructive talk (forcefully converted from PowerPoint via Ooffice) by Frédéric.

Daniela Bauer
Last modified: 08/AUG/06