US ATLAS Muon Software Activities

Thomas Moore University of Massachusetts, Amherst 1 st North American ATLAS Physics Workshop December 20, 2004

Outline

 Development of Moore/MuID  Software Validation  single muons  H  4    Muon Event Data Model Detector Validation with W  ,Z 0  Effects of wire sag on RT functions T.B.Moore

December 2004

G. Stavropoulos

Reconstruction with Moore/MuID

   Muons in ATLAS traverse:    Inner Detector (best at low p T ) Calorimeters (E loss  3 GeV) Muon Spectrometer (best at high p T ) Moore:

Muon Object Oriented Reconstruction

in the MS.

MuID:   

Calorimeter correction

Extrapolation of the Moore track to the IP with parameterized multiple scattering and energy loss.

Tracks from Inner Det and MS are combined with a  2 cut-off.

Final fit of successfully combined tracks.

Matching with the inner tracks and combined fit

December 2004 T.B.Moore

First measured point

Muon Software Validation

      Provide rapid feedback for each analysis release.

Identify areas in need of improvement.

Provide and test software recipes.

Catalog changes w/r to previous releases.

Provide reference plots to track performance vs time. Validation channels currently include:    single muons Z 0   +  Higgs  4   SUSY T.B.Moore

December 2004

http://cern.ch/muondoc/Software/Validation

Validation Web Page

Release Validation Table: Inventory of Validation Studies: Links to detailed plots, recipes, validation samples, release notes, etc… December 2004 T.B.Moore

N.Benekos, T.M., S.Willocq

  

Validation with single muons

CBNT ntuples produced with MooMakeNtuplePulls, MuidNtuple, MuidIDNtuple, MuidCombNtuple .

Improvement!

9.2.0(G4 DC2) Root Macros available in package: MuonSpectrometer/Moore/ MooPerformance Produce plots for Moore, InnerDetector, MuID Standalone, MuID combined:  Efficiency vs η and φ   Residuals and pulls of the 5 track perigee parameters #of hits,  2 , probability T.B.Moore

December 2004

Material Studies(I)

8.4.0 (G3)

material_scenario = -1

8.4.0 (G4)

Originally, jobOptions for processing G4 MC had no dead material description.

pulls ~OK for G4 using material parameterization

tuned with G3

, i.e. material_scenario = 1) December 2004 T.B.Moore

material_scenario = 1

8.7.0 (G4)

Material Studies(II)

Parametrized Material Geantino Map Phi Regions December 2004 | η| > 2 Geantino map shows improved description of material for muons passing through toroid coils 4 phi bins: 1=“A”, 2=“B1”, 3=“C”, 4=”B2” T.B.Moore

Single Muon Conclusions

   Little change in G4 performance with 8.7.0, 8.8.0, 9.0.0. Release 9.2.0 shows improved ε for |η|  2  Due to changes in CSC clusterization Propose Geantino map to be the default in future releases.

 Layout Q: Unable to run digitization due to lack of updated cabling maps for digit/RDO conversion 

Workaround

: skip RDOs and reconstruct directly from digits  Ongoing tests of RPC digits vs clusters in 9.0.0

Plans    Study impact of pile-up, cavern background Extend validation to hit level and ESD & AOD Develop automatic validation T.B.Moore

December 2004

K.Assamagan, A.Khodinov (BNL)

H



ZZ

(

*

) 

4

     100k events simulated   m H = 130 GeV ATLSIM(6.5.0)  ATHENA(7.0.2) Comparisons of MuID standalone, Muonbox and MuID combined Uses Z 0 mass constraint and improved combinatorics compared to TDR analysis.

MuID combined:   Mean m H  = 130.2 GeV = 1.56 GeV T.B.Moore

December 2004

Reconstruction Status and Plans

      Moore/MuID is performing well.

Test beam validation is very important  another talk covered in Studies with cavern background/pile-up are needed Use of Calo information in MuID to be revisited.

Work to incorporate alignment in Athena has begun:    MuonAlignment package created to interface with conditions DB Compatible with MuonGeoModel (I. Trigger) Incorporate the

Interval of Validity

service to update the alignment constants from the conditions DB when new measurements are available. Currently being tested. (T.M.) Plan to study the material description using the

Geantino Map

technique. (A.Nairz,T.M.) T.B.Moore

December 2004

K.Assamagan (BNL)

Muon EDM Status

 Crash in RPC/MDT digitization due to cabling services not updated for layout Q  Temporary solution: use persistified digits  Common track class (Trk::Track) implemented for MOORE In Progress…  MuID should directly construct Trk::Track    Both MOORE and MuID should produce collections of Trk::Track in StoreGate Both MOORE and MuID should construct TrackParticles & produce collections of TrackParticles These updates should be in place for release 10.0.0 for Rome Physics Workshop T.B.Moore

December 2004

B.Zhou, E.Diehl, T.Dai (Michigan)

Validating ATLAS with W



and Z

0     Expect large W    and Z 0 ~ 30 Hz for W +  +  ~ 3 Hz for Z 0  +  Muons from W  event rates at the LHC (87M events/month) (8.4M events/month) and Z 0 decays can provide:       Software validation Check of MS alignment using high p T tracks Calibration of B-Field, MDT RT-functions using Z 0 mass spectrum Trigger efficiency and muon identification studies using Z 0  +  Jet energy scale and missing E T resolution using Z Luminosity determination using W and Z events 0 +jet events Techniques have been proven at D0 For more info: http://agenda.cern.ch/fullAgenda.php?ida=a045663 T.B.Moore

December 2004

    

Tag-Probe Method

 Z 0 Using Z  0  +  , apply tight cuts to one ( tag ) and use the other ( probe ) to evaluate  cut efficiencies.

Fit Z 0 mass spectrum to determine signal and background events After requiring some selection on the probe muon, re-fit mass spectrum.

Selection efficiency is the ratio of signal events in the two fits.

Can be used for trigger, detection, and selection efficiencies as a function of p T , η, and φ T.B.Moore

December 2004

Example: Isolation Cut Efficiency

D0 data: S1 S2 Muon Isolation Efficiency = S2/S1 Many other muon detection efficiencies can be determined in the same way December 2004 T.B.Moore

W

±

,Z

0

Calibration Plan

   Establish baseline performance plots using DC2 W  , Z 0 , J/  samples:    p T spectra vs η Mass spectra vs η Detection efficiencies with certain selection cuts vs η  Angular distributions and correlations Vary detector calibration parameters (RT-functions, alignment and shape deformation, B-field) to study effects on baseline spectra with DC3 MC.

Develop method and programs for detector validation to be ready for day-one LHC collisions. T.B.Moore

December 2004

Wire Sag

D.Levin, E.Diehl, A.Thrall (Michigan)

Chamber wire sag inferred from inplane alignment system BILR pt is off Fit to Garfield pts Slope: 3.5 μm/ns Y-int: 6.1 μm Residuals: 6 μm Lose sensitivity below 100 μm sag

   MDT chambers have up to 500 μm wire sag which should be corrected for in tracking.

Wire sag causes a “step” in the end of the TDC spectrum due different max drift times above/below wire. The step “width” can be measured by fitting to a double sigmoid.

The TDC step width scales linearly with wire sag and can be used to evaluate wire sag during chamber commissioning and operation.

December 2004 T.B.Moore

Wire Sag Correction

BILR  = 85  Garfield RTs for: centered wire 250  off-center 500  off-center  =69    Use Garfield simulation to calculate an RT function correction based on effective wire sag. (effective: account for beam angle relative to wire sag).

A preliminary correction made to the H8 BILR data improves tracking residuals December 2004 T.B.Moore

Conclusions

      There are many interesting projects underway in muon software.

A web page has been set up to document validation results at http://cern.ch/muondoc/Software/Validation Reconstruction software and EDM are being developed at UMass and BNL.

Michigan group is studying W ± , Z 0 control samples which will be invaluable for evaluating many aspects of ATLAS performance Michigan wire sag studies show promise for improving tracking residuals.

There are still many opportunities to get involved.

T.B.Moore

December 2004