DT Simulation Validation

DT Simulation Validation

J. Santaolalla, B. de la Cruz (CIEMAT, Madrid)

Muon Barrel Workshop, 28th September 2010

Outline

DT Simulation Validation:

SimHits

Digis

RecHits

Segments

Description of Validation Twiki Page

DT Simulation Validation

Quantities validated:

SimHits: Test of Geometry, Occupancies, muon hits generated, energy deposited in gas, loss of muon momentum traversing magnet yoke…

Digis: SimHits digitization using smeared Garfield parametrization, with some corrections. Test number of digis and time distribution.

RecHits: Single hit resolution and pulls with a granularity of chambers. Dependence with muon incident angle, hit position in cell.

Segments: Spatial and angular resolutions, pulls.

■ At this level, validation programs well established and automatized, only occassional changes in validation code.

■ This fact resembles stability of muon simulation.

► MC samples: ■ Standard validation procedure up to now. ■ Allow to validate different CMSSW versions. ■ Uses Simulated RelVal files ►Single muon files (flat in , , fixed pt) with ideal detector

conditions ► Physical process production (Z, top) with Startup (realistic)

conditions usually 10000 evts per sample.

► Real data : ■ from Cosmics Runs useful to establish first

calibrations and first parameters values,

■ from pp Collisions already enough statistics to be used as well for Validation, from now on

DT Validation samples

Outline


SimHits

Digis

RecHits

Segments


From DT offline analysis:/cms/MUON/dt/sx5/Results/GlobalRuns/Beam2010/Collisions

DT SimHits: Geometry

Wheel 0

SingleMuon MCCollision Data

Run 143953

SimHit Validation checks Geometry and Occupancies in Simulation, but without realistic detector conditions

■ No noisy cells

■ No missing cells, layers…

Cell number

Cell numberMB1

MB2

MB3

MB4

MB4

MB3

MB2

MB1

Qualitative

MC-Data Comparison

/RelValSingleMuPt100/

DT SimHits: Occupancies

SingleMuon MC

All Wheels Wheel -2

Wheel -1

Wheel 0

Wheel +1 Wheel +2

Collision Data

Run 143953

■ Highest occupancies in W0 and smallest in W2 (Sim & Data)

■ Comparison just qualitatively as data contains noise and hits outside time window not simulated.

All Sectors

MB4 2nd station S4, S10


DT SimHits

SingleMuon MC

Collision Data

Run 143953

MC

● Data

Distrib Distrib


Outline


SimHits

Digis

RecHits

Segments


DT Digitization in Simulation Chain

Parameters entering the digitization:

Drift velocity (from Garfield parametrization), takes into account non-linearities, B field effects

Velocity of Propagation along wire = 24.4 cm/ns

Deadtime between 2 digis in same cell = 150ns

Muon TOF Correction (1 per SL)

To_like_delay (offset)

Validation:

Drift Time Distributions (Timeboxes)

Number of Digis generated from original SImHits

DT Digis comparison: simulated-real data

Time (ns)

Time (ns)

Simulated data from RelVal single muonComparison of timeboxes

distributions in real and simulated data is quite good, although occassionally real effects appear…

Collision Data

Run 143953

Unphysical signals in drift

time distributions

DT Digis in real data Examples: noisy/missing cells

Due to noisy cells in layer 4

Unphysical signals in drift time distributions

Cell number

Small signal in layer 1

Due to noisy cells in layer 4

Due to missing cells in layer 1

Time (ns

Cell number

Simulation of Detector Real Conditions

The DT muon simulation is becoming more realistic now (parameters and resolutions now injected from muons from collisions and not CRAFT) but nevertheless real conditions (noisy cells, dead cells, etc ) not included in simulation, but stored in DB and ready to be used at reco level, if needed.

Dead cells: negligible number of disconnected cells ( 0.5% )

Noisy cells: DT Noise rate (5Hz) is coming from isolated single cells with high hit rate for the moment not included in simulation, but could be masked at Reco level if convenient.

Do we (DTs) need that simulation cope with IOV-dependent conditions of the

detector, following the DT chambers status along time?

Probably not at SIM level, but at RECO one

Outline


SimHits

Digis

RecHits

Segments


RecHits

Comparison SimHit – RecHit (resolution and pull) for: 1D RecHits

Step 1 Step 3

Granularity Plots split by wheel, chamber and view (phi, Z)

Samples: RelValSingleMuPt100 MC IDEAL conditions RelValZMM MC STARTUP conditions

Also…: Resolution/Pull vs Eta Resolution/Pull vs Phi Resolution/Pull vs Impact angle Resolution/Pull vs Distance to wire

RecHits (some plots)

CMSSW381CMSSW381ResolutionS1 Rphi (all wheels,…)RelValSingleMuPt100

CMSSW381CMSSW381ResolutionS1 Rphi (all wheels,…)RelValSingleMuPt100

RecHit - SimHit (cm)

Rec

Hit

- S

imH

it (c

m)

Rec

Hit

- S

imH

it (c

m)

Angle (rad) Phi (rad)

eta Distance to wire (cm)

μ = -0.003 (cm)σ = 0.026 (cm)

RecHits (some plots)

CMSSW381CMSSW381Pull1D S1 Rphi (all wheels,…)RelValSingleMuPt100

CMSSW381CMSSW381Pull1D S1 Rphi (all wheels,…)RelValSingleMuPt100

Angle (rad) Distance to wire (cm)

Same for Step 3, RZ,…In total 302 plots for each sample (MuPt100 and ZMuMu)Same for Step 3, RZ,…In total 302 plots for each sample (MuPt100 and ZMuMu)

Outline


SimHits

Digis

RecHits

Segments


DTSegments

Similar plots to RecHits ones Comparison SimHit (segment) – RecHit (segment) with resolution

and pull plots for: x position, y position, α angle, β angle 2D and 4D segments

Granularity Plots split by wheel

Samples: RelValSingleMuPt100 MC IDEAL conditions RelValZMM MC STARTUP conditions

Also…: Resolution/Pull vs Eta Resolution/Pull vs Phi

DTSegments

CMSSW381CMSSW381ResolutionRphi (all wheels,…)RelValSingleMuPt100

CMSSW381CMSSW381ResolutionRphi (all wheels,…)RelValSingleMuPt100

RecHit – SimHit (cm), segment x pos

RESIDUAL PULL

μ = -2e-5 (cm)σ = 0.010(cm)

Outline


SimHits

Digis

RecHits

Segments


Web site

All plots in the web site:

http://cms-service-dtrechitvalidation.web.cern.ch

Easy to browse

Spotting problems...

CMSSW381CMSSW381CMSSW381CMSSW381 CMSSW382CMSSW382CMSSW382CMSSW382

Pu

llP

ull

Res

olu

tio

nR

eso

luti

on

Narrower

Longer Tail

??

??

RelValSingleMuPt100RelValSingleMuPt100

Spotting problems...

CMSSW381CMSSW381CMSSW381CMSSW381 CMSSW382CMSSW382CMSSW382CMSSW382

Pu

llP

ull

Res

olu

tio

nR

eso

luti

on

Due to a more realistic vdrift

table

(OK)(OK)

More realisticerrors

(OK)(OK)

RelValSingleMuPt100RelValSingleMuPt100

Conclusions

DT Validated in four steps: SimHits, Digis, RecHits, and Segments

Validation programs quite stable and established, only occasional developments.

Still to improve: MC-Data comparison.

Public web page to check changes in RecHits and Segments

Plots used shown to be useful to spot problems or as a confirmation of changes.

DT Simulation Validation

Documents

Transcript of DT Simulation Validation