Muon Event Filter

1
Muon Event Filter

• Stefania Spagnolo
• Dip. Fisica, Univ. Lecce e Sezione INFN, Lecce
• on behalf of
• the Muon HLT working group

2
Outline

• Brief reminder
• the requirements the implementation the studies
  so far
• Status of the TrigMoore package
• Performance on recent releases (focus on the
  End-Cap region)
• resolution and efficiency
• Trigger rates at the EF vs threshold
• Plans
• sw developments and physics studies

3
Brief reminder

• Physics and system Requirements
• EF must reduce the total data throughput to 200
  Hz
• EF total latency 1-2 s
• PT reach of the lvl1 muon trigger ? 5 GeV/c
  (lower limit)
• Muon rate is dominated, at low pt, by decays in
  flight of light mesons, b and c quarks
• LVL1 muon rate for pT gt 6GeV ? 25 kHz _at_ 1033
  cm-2s-1
• Cavern background and pileup at high luminosity
  are a source of fake muons
• Physics needs high efficiency and selectivity,
  flexibility in order to cope with different
  background scenarios
• The implementation
• TrigMoore an interface to the HLT Steering for
  the offline muon reconstruction algorithms MOORE
  and MuId

4
Brief reminder
LVL1
TrigMoore a schematic view
Thanks to the ID tracking group particularly to
Alan Poppleton (iPatRec default ID reco)
LVL2 (muFast)

• Two different running modes
• Seeded
• Reconstruction performed only in the geometrical
  regions provided by the RoIs of previous levels.
• Full scan
• Full reconstruction, equivalent to the offline
  working mode

Seeding Algs
Moore Algs
Hypo Alg
TrigMoore
MuIdStandAlone Algs
Hypo Alg
Full functionality in barrel and end-caps
MuIdCombined Algs
Seed can come from LVL1 or LVL2
Hypo Alg
ESD and AOD from the muon EF available
5
Brief reminder

• Status at the last TP week
• from the side of the algorithm
• TrigMooreHypo first implementation
• developments for muon EF output in ESD and AOD
  validated by comparing TrigMoore AOD with Moore
  AOD in the same job (11.0.5)
• (slightly out of the scope of HLT) MuId migrated
  to use as input the generic track object
  TrkTrack Allows to choose among different
  reconstruction algorithms in the ID
• From the side of the performance
• timing measurements on single muons with pile-up
  and nominal cavern background (400 ms average,
  500 ms RMS) room for improvement !
• trigger rates estimated in the BARREL shown at
  the March TP week (on Rome-workshop data)
  confirmed by with more recent simulation samples
  and software suite
• studies of fakes at high luminosity

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Status of the TrigMoore package
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Status of the TrigMoore package
in 12.0.3

• Seeding Algorithms assume the seed is a
  MuonFeature (from muFast _at_ LVL2) or a LVL1 roi
  (seed from LVL1)
• 3 istances of TrigMoore called by the steering,
  for reconstruction in the MS, extrapolation to
  the IP and combination with ID tracks, allow hypo
  algos to be run at each step (if requested)
• TrigMoore records in the TE history a
  MooTrackContainer or a MuidTrackContainer for
  each seeding ROI and they are accessed by
  TrigMooreHypo for pT test
• TrigMoore records all reconstructed tracks in the
  event in a single container in StoreGate for
  conversion in TrkTrack format and subsequent
  output in ESD and AOD

Seeding Algs
Moore Algs
Hypo
MuIdStandAlone Algs
Hypo
MuIdCombined Algs
Hypo
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Status of the TrigMoore package

• Seeding Algorithms assume the seed is a
  MuonFeature (from muFast _at_ LVL2) or a LVL1 roi
  (seed from LVL1)
• 3 istances of TrigMoore called by the steering,
  for reconstruction in the MS, extrapolation to
  the IP and combination with ID tracks, allow hypo
  algos to be run at each step (if requested)
• TrigMoore records in the TE history a
  MooTrackContainer or a MuidTrackContainer for
  each seeding ROI and they are accessed by
  TrigMooreHypo for pT test
• TrigMoore records all reconstructed tracks in the
  event in a single container in StoreGate for
  conversion in TrkTrack format and subsequent
  output in ESD and AOD

a problem for the integration in the online
not very flexible for 13.0.0 will separate into
3 packages
Trigger Aware analyses can use the muon EF
result by looking at the AOD/ESD content but
cannot run the hypothesis algos on AOD
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Status of the TrigMoore package

• First use of the TrigRoIDescriptor
• for the online integration and for running more
  general sequences (seed can come from whatever
  LVL2 HLT algorithm)
• new tag (TrigMoore-00-00-68) collected in 12.0.X
  and 12.0.3-LST
• Allow running the hypothesis algorithm on AOD
  will be in 12.0.4
• Convert Moo(Muid)Tracks into TrkTrack for each
  ROI and assign KEY2KEY to each of them in order
  to allow navigability
• Change input toTrigMooreHypo (to Containers of
  TrkTrack)
• Ongoing work to increase modularity
• well have 3 HLTalgos instead of 3 instances of
  TrigMoore by 13.0.0
• Online integration
• problem in the retrieving of L2Result information
  from ByteStream solved with the use of the
  TrigRoIDescriptor
• jobOptions for the online
• works fine in the offline  tested in the online
  (athenaPT)  OK
• Event Filter seeded by LVL1    under test
• Also preliminary check for pre-series tests OK
• next week the Large Scale Test will start
  TrigMoore there !

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Performance on recent releases
11
Performance on recent releases
The Sample Single muons with fixed pT between 2
and 75 GeV/c CSC production with Athena 11.0.42
(Napoli Tier2 CERN) Muon Layout Q02
Reconstruction in Athena 12.0.3, TrigMoore seeded
by LVL1 skip LVL2 in order to test EF
coherently in barrel and endcaps
No relevant bias within statistical errors
Check pT rec / pT gen vs h MEAN (of a gaussian
fit) shows reconstruction biasesSIGMA gives
relative pT resolution

• Blue MOORE, for tracks with c2 lt3
• Red MuidSA, for tracks successfully fitted
• Pink MuidCB, for tracks successfully fitted

h
Pretty stable with pT
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Performance on recent releases
Relative pT resolution as a function of h from
s(pTrec/pTgen)
Expected trend observed degraded resolution in
the transition region between the barrel and
endcap toroidal fields

• s(pT)/pT vs h

s(pT)/pT vs h
pT 8 GeV/c
pT 40 GeV/c
h
h
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Performance on recent releases
pT 8 GeV/c
Relative pT resolution as a function of pT from
s(pTrec/pTgen)
stable compared to results in previous releases
pT 8 GeV/c
pT 8 GeV/c
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Moore Efficiency
Performance on recent releases
Efficiencies are defined wrt LVL1 accepted muons
edge at h 2.4
inefficiencies in the feet region
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Efficiency vs pT
Performance on recent releases
Moore, MuidSA OK Unexpected efficiency loss (5)
of MuidCB compared to MuidSA similar behaviour
in the offline package (efficiency wrt MC-truth)
http//muondoc.web.cern.ch/muondoc/Software/Valid
ation/singlemu/12.0.1/singlemu.html
Under investigation - tighter cuts in the
machting account for 2 eff. loss - no
obvious trend with h and f - what else ? plan to
fix by 12.0.4

• Blue MOORE, for tracks with c2 lt3
• Red MuidSA, for tracks successfully fitted
• Pink MuidCB, for tracks successfully fitted

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Trigger Rates
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Trigger Rates

• Rates at the EF can be estimated by folding cross
  sections with
• Efficiency of LVL1 for a given pT threshold
• Efficiency of LVL2 w.r.t. LVL1 seed (skipped,
  i.e. e 1)
• Efficiency of EF w.r.t. seeding algo (LVL1 in
  this study)

deserve detailed study
The effect of skipping the LVL2 selection step
test in the barrel rates LVL1EF increase by
?10 for mu(6) with respect to LVL1LVL2EF
?30 for mu(20)
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Trigger rates
First exercise to look at rates at pT thresholds
different than the typical scenarios 6 and 20
GeV/c
Luminosity set to 1033 cm-2s-1
efficiencies for LVL1 from F. Conventi for 6,
8, 10 GeV/c (in good agreement with our
estimates) our estimates for 11, 20, 40 GeV/c
Typical scenarios mu(6) 3.0 kHz mu(20) 25
Hz
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Trigger rates
First exercise to look at rates at the EF in the
END CAPS and vs pT thresholds
Luminosity set to 1033 cm-2s-1
Efficiencies for LVL1 from our estimate maybe
slightly inaccurate for the known bugs in
TGCCabling expected effects at EF lt10
Typical scenarios mu(6) 3.1 kHz mu(20) 27
Hz
Barrel EndCap EF Rate _at_ 1033 cm-2s-1
mu(6) 6.1 kHz mu(20) 52 Hz
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Trigger Rates
Rate for mu(5) at the EF in the barrel use LVL1
efficiency for the barrel with the trigger
re-configured to have 5GeV/c as lowest threshold
Luminosity set to 1033 cm-2s-1
Muon sources 5 GeV/c threshold kHz 6 GeV/c threshold kHz
?/K 5.0 1.9
b 1.2 0.67
c 0.65 0.34
W 0.003 0.003
t negligible negligible
Total 6.9 kHz 3.0 kHz
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Conclusions

• TrigMoore provides the requested functionality of
  the muon EF
• from the sw architecture point of view
  (increasing modularity, compliant with trigger
  aware analysis needs)
• plan to follow up the successful Moore migration
  to the new EDM
• from the physics performance point of view (but
  room for refinements exists !)
• First exercise to provide rates vs threshold
  input for the definition of trigger menus
• integrate the LVL2 (standalone and combined) in
  the chain
• Plans
• revise studies with cavern background and pile-up
  
• revise studies of rejection of muons from p/K
  decays
• dedicated CSC simulations requested
• pursue timing optimization