Muon Event Filter

Stefania.Spagnolo, Dip. Fisica, Univ. Lecce CERN, Nov. 2006, ATLAS Trigger and Physics week

Muon Event FilterMuon Event Filter

Stefania SpagnoloDip. Fisica, Univ. Lecce e Sezione INFN, Lecce

on behalf of

the Muon HLT working group


Outline

Brief reminderthe 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

Planssw developments and physics studies


Brief reminder

Physics and system RequirementsPhysics and system Requirements EF must reduce the total data throughput to 200 HzEF total latency ~ 1-2 sP

T 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 > 6GeV 25 kHz @ 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 implementationThe implementationTrigMoore: an interface to the HLT Steering for the offline muon reconstruction algorithms: MOORE and MuId


LVL2 (muFast)LVL2 (muFast)

Moore AlgsMoore Algs

LVL1LVL1

MuIdStandAloneMuIdStandAloneAlgs Algs

TrigMooreTrigMoore

Seeding AlgsSeeding Algs

MuIdCombinedMuIdCombinedAlgs Algs

Hypo AlgHypo Alg

Hypo AlgHypo Alg

Hypo AlgHypo Alg

Brief reminder

TrigMoore: a schematic view

Two different running modes:

SeededSeededReconstruction

performed only in the geometrical regions provided by the RoIs of previous levels.

Full scanFull scanFull reconstruction,

~equivalent to the offline working mode

Full functionality in barrel and end-caps

Seed can come from LVL1 or LVL2

ESD and AOD from the muon EF available

Thanks to theID tracking group; particularly to Alan Poppleton(iPatRec default ID reco)


Brief reminder Status at the last T&P week

from the side of the algorithm:TrigMooreHypo – first implementationdevelopments 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: Trk:Track; 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 T&P week (on Rome-workshop data) confirmed by with more recent simulation samples and software suitestudies of fakes at high luminosity




Moore AlgsMoore Algs

MuIdStandAloneMuIdStandAloneAlgs Algs

Seeding AlgsSeeding Algs

MuIdCombinedMuIdCombinedAlgs Algs

HypoHypo

HypoHypo

HypoHypo


Seeding Algorithms assume the seed is a MuonFeature (from muFast @ 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 p

T test

TrigMoore records all reconstructed tracks in the event in a single container in StoreGate for conversion in Trk:Track format and subsequent output in ESD and AOD

in 12.0.3



Seeding Algorithms assume the seed is a MuonFeature (from muFast @ 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 p

T test

TrigMoore records all reconstructed tracks in the event in a single container in StoreGate for conversion in Trk:Track 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

resultby looking at the

AOD/ESD content but cannot run the

hypothesis algos on AOD


First use of the TrigRoIDescriptorfor 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 Trk:Track for each ROI and assign KEY2KEY to each of them in order to allow navigability Change input toTrigMooreHypo (to Containers of Trk:Track)

Ongoing work to increase modularity: we’ll 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 TrigRoIDescriptorjobOptions for the online

works fine in the offline; tested in the online (athenaPT) OKEvent Filter seeded by LVL1 under test

Also preliminary check for pre-series tests OKnext week the Large Scale Test will start – TrigMoore there !



Performance on recent releases



Blue = MOORE, for tracks with 2 <3Red = MuidSA, for tracks successfully fittedPink = MuidCB, for tracks successfully fitted

No relevant bias within statistical errors

Check pT rec / pT gen vs

MEAN (of a gaussian fit) shows reconstruction biasesSIGMA gives relative pT resolution

The SampleSingle muons with fixed pT between 2 and 75 GeV/cCSC 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

Pretty stable with pT



pT)/pT vs

Expected trend observed: degraded resolution in the transition region between the barrel and endcap toroidal fields

pT)/pT vs

Relative pT resolution as a function of from (pTrec/pTgen)

pT = 8 GeV/c pT = 40 GeV/c


MOOREMOORE

MuidSMuidSAA

MuidCMuidCBB

Performance on recent releasesRelative pT resolution as a function of pT

from (pTrec/pTgen)stable compared to results in previous releases

pT = 8 GeV/c

pT = 8 GeV/c

pT = 8 GeV/c


Moore Efficiency

ETAETA

PHIPHI


inefficiencies in the feet region

Efficiencies are defined wrt LVL1 accepted muons

edge at = 2.4


Efficiency vs pT


Under investigation:

- tighter cuts in the machting account for ~2 % eff. loss- no obvious trend with and - what else ?

plan to fix by 12.0.4

Blue = MOORE, for tracks with 2 <3Red = MuidSA, for tracks successfully fittedPink = MuidCB, for tracks successfully fitted

Moore, MuidSA OKUnexpected 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/Validation/singlemu/12.0.1/singlemu.html


Trigger Rates


Trigger Rates

TT

_cutoffp

_p T

i

i ) dp(pεdp

dσR

T

T

inf

L

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. ) Efficiency of EF w.r.t. seeding algo (LVL1 in this study)

The effect of skipping the LVL2 selection step: test in the barrelrates LVL1+EF increase by 10% for mu(6) with respect to LVL1+LVL2+EF 30% for mu(20)

deserve detailed study


First exercise to look at rates at pT thresholds different than the typical scenarios: 6 and 20 GeV/c

Trigger rates

Luminosity set to 10Luminosity set to 1033 33 cmcm-2-2ss-1-1

Typical scenarios:

mu(6) 3.0 kHz

mu(20) 25 Hz

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


First exercise to look at rates at the EF in the END CAPS and vs pT thresholds

Trigger rates


Typical scenarios:

mu(6) 3.1 kHz

mu(20) 27 Hz Barrel + EndCap EF Rate @ 10103333 cm cm-2-2ss-1-1 mu(6) 6.1 kHz mu(20) 52 Hz

Efficiencies for LVL1from our estimate

maybe slightly inaccurate for the

known bugs in TGCCabling

expected effects at EF <10%


Trigger Rates

Muon sources

5 GeV/c threshol

d

kHz

6 GeV/c threshol

dkHz

/K/K 5.0 1.9bb 1.2 0.67cc 0.65 0.34WW 0.003 0.003

ttnegligibl

enegligibl

eTotalTotal 6.9 kHz6.9 kHz 3.0 kHz3.0 kHz

Rate for mu(5) at the EF in the barreluse LVL1 efficiency for the barrel with the trigger re-configured to have 5GeV/c as lowest threshold



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 EDMfollow up the successful Moore migration to the new EDMfrom 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 /K decays

dedicated CSC simulations requested

pursue timing optimization

Documents

Muon Event Filter