aspects of lar reconstruction s. rajagopalan atlas week june 4, 2001

Aspects of LAr ReconstructionAspects of LAr Reconstruction

S. RajagopalanS. Rajagopalan

ATLAS WeekATLAS Week

June 4, 2001June 4, 2001

ATLAS Week, 4 June 2001ATLAS Week, 4 June 2001LAr ReconstructionLAr Reconstruction

OverviewOverview

Calorimeter Reconstruction in ATRECON J. Schwindling et. al.J. Schwindling et. al. Successfully used in Physics TDRSuccessfully used in Physics TDR Now used as a benchmark for testing new codeNow used as a benchmark for testing new code

Migration to OO Work began in October 1999Work began in October 1999 Primary people involved today are: Primary people involved today are: (~ 5 FTE for (~ 5 FTE for

2001)2001)F. Lanni, H. Ma, S. Rajagopalan, K. Yip (BNL)F. Lanni, H. Ma, S. Rajagopalan, K. Yip (BNL)

A. Radu, M. Wielers (Triumf)A. Radu, M. Wielers (Triumf)

J. Collot, F. Ohlsson-Malek, S. Albrand (Grenoble)J. Collot, F. Ohlsson-Malek, S. Albrand (Grenoble)

P. Loch (Arizona)P. Loch (Arizona)

J. Schwindling, J.P. Meyer (Saclay)J. Schwindling, J.P. Meyer (Saclay)

E. Frank, A. Gupta, F. Merritt (Chicago) : TileE. Frank, A. Gupta, F. Merritt (Chicago) : Tile


Major Milestones MetMajor Milestones Met Early design in PASO: Early design in PASO: Jan. 2000Jan. 2000 Migrate to Athena: Migrate to Athena: May 2000May 2000

LAr Reconstruction used as a test bed for early AthenaLAr Reconstruction used as a test bed for early Athena First application software to successfully migrate to AthenaFirst application software to successfully migrate to Athena

3 working days at LBL3 working days at LBL

First Common Calorimeter InterfacesFirst Common Calorimeter Interfaces Oct. 2000Oct. 2000 QA review of then available components QA review of then available components Dec. 2000Dec. 2000

S. Albrand (Grenoble) S. Albrand (Grenoble) Combined Reconstruction (egamma) Combined Reconstruction (egamma) Jan. 2001Jan. 2001 Process Process GEANT4GEANT4 LAr Hits (Root Objects) LAr Hits (Root Objects) Mar. 2001Mar. 2001 Lund ReleaseLund Release June 2001June 2001

Establishing most of the reconstruction chainEstablishing most of the reconstruction chain From G3/G4 Hits to Particle IdentificationFrom G3/G4 Hits to Particle Identification


Algorithms & DataObjectsAlgorithms & DataObjects The design/packaging of the LAr reconstruction The design/packaging of the LAr reconstruction

programs follow the basic principle of the Athena programs follow the basic principle of the Athena FrameworkFramework

Data ObjectData Object

eg: A collection of cellseg: A collection of cells

Data ObjectData Object

eg: A collection of clusterseg: A collection of clusters

Algorithm(s)Algorithm(s)

ClusteringClusteringalgorithmsalgorithms+ associated+ associatedcorrectionscorrections

Data Objects reside in the Transient Data Store (TDS). Data Objects reside in the Transient Data Store (TDS).

Algorithms produce Data Objects and record them in the TDS.Algorithms produce Data Objects and record them in the TDS.

If reading/writing a DataObject from/to disk (persistent media), If reading/writing a DataObject from/to disk (persistent media),

a converter needs to be provided.a converter needs to be provided.


Transient Event Store

Digits

Data FlowData Flow

D DD

c cc

C CC

CellReconstruction

Cells

ClusterReconstruction

Clusters

Analysis(ntuples)


LAr Data ClassesLAr Data Classes Data Objects proposed/implemented in March Data Objects proposed/implemented in March

20012001 J. Collot et. al.J. Collot et. al.

T.

D.

S.

Simulation Hits

DetRespSimulation RawChannels , Digits

CellBuilder

EventFilter/Builder

Electronics Calib

ClusterReconstruction

Hits

Cells

RawChannels , Digits

Digits

RawChannelsCells

Clusters

RawChannels , Digits

TBConvDigits

Test beam Zebra Tapes

HitConvHits

Objy , ROOT/IO


LAr Algorithm & Data ObjectsLAr Algorithm & Data Objects

Algorithms/(Packages) Data Objects

G3/G4 LArHit

Digitization LArDigit

ROD package LArRawChannel

Cell Reconstruction CaloCell

Tower Reconstruction CaloTower

Cluster Reconstruction CaloCluster

egammaRec egamma

tauRec tauObject

JetRec jet

MissingET MissingET


Data Access by LAr AlgorithmsData Access by LAr Algorithms LArHit: Describes the G3/G4 LAr HitsLArHit: Describes the G3/G4 LAr Hits Collection of LArHit read from persistency Collection of LArHit read from persistency (Hong (Hong

Ma)Ma) using “Converters” in Athena using “Converters” in Athena Collection made available in the Transient Data Store Collection made available in the Transient Data Store

(TDS) for algorithms to process.(TDS) for algorithms to process.GEANT3GEANT3 Zebra Zebra FileFile

ZebraCnvZebraCnv RD RD EventEvent

LArHitLArHitZebraCnZebraCnvv LArHitLArHit

CollectionCollection

GEANT4GEANT4 Root FileRoot File LArHitLArHitRootCnvRootCnv

Work with Objectivity in progress, but not yet used by LAr


DigitizationDigitization Digitization Package: Digitization Package: (F. Lanni, J.P. Meyer, J. (F. Lanni, J.P. Meyer, J.

Schwindling)Schwindling) Emulation of the FEB in the Athena Framework:Emulation of the FEB in the Athena Framework:

Uses a simple gain selection mechanismUses a simple gain selection mechanism Input from G3 HitsInput from G3 Hits Additional Inputs: Gain, waveform profile, noise levelAdditional Inputs: Gain, waveform profile, noise level

Hardwired in code, needs to migrate to a Database.Hardwired in code, needs to migrate to a Database. Output: LArDigit containing 5 samples per channelOutput: LArDigit containing 5 samples per channel

Work in progress, first prototype is available.Work in progress, first prototype is available.

Adding Pile-up in Athena Adding Pile-up in Athena (M. Wielers)(M. Wielers) Cannot read multiple events in Athena at presentCannot read multiple events in Athena at present Can read old Zebra pile-up tapes (E Matrices) in AthenaCan read old Zebra pile-up tapes (E Matrices) in Athena

Signal+Pile-up events produced for “physics TDR” Signal+Pile-up events produced for “physics TDR” (Single electrons & photons, H (Single electrons & photons, H , jets), jets)


Cluster Reconstruction on Pile-up Cluster Reconstruction on Pile-up EventsEvents


Pile-up comparison with Pile-up comparison with ATRECONATRECON


Kin YipKin Yip (+ B. Cleland, F. Lanni) (+ B. Cleland, F. Lanni)

Compute E, t, 2 from LArDigit (5 samples)

ROD Package in AthenaROD Package in Athena

Geant3Geant3

TestBeam DataTestBeam Data

2

A = observed amplitude in sample

and are optimal filtering coeffici

1E = A t = A

E

= A - (g E +

ents

g , g are the waveform paramete

t

rs

g E )

i i i ii i

i i i

i

i

i

i

i i

i

b

a

a

b

DigitizationDigitizationLArHitLArHit

ROD PackageROD PackageLArDigitLArDigit

LArRawChannelLArRawChannel


Analysis of 50 GeV photons at Analysis of 50 GeV photons at =0.3 through =0.3 through Digitization & ROD packagesDigitization & ROD packages


Cell ReconstructionCell Reconstruction

Several collections of CaloCell in Transient Data StoreSeveral collections of CaloCell in Transient Data Store Collections can be keyed by regionsCollections can be keyed by regions Collections can be keyed by algorithms producing Collections can be keyed by algorithms producing

themthem Downstream algorithms Downstream algorithms (Clustering/Particle ID)(Clustering/Particle ID) can simply can simply

request the CaloCell collections by specifying the keyrequest the CaloCell collections by specifying the key

Geant3Geant3 G3 Cell BuilderG3 Cell Builder CaloCellCaloCellLArHitLArHit

DigitizationDigitization

LArHit

RODROD CellBuilderCellBuilder CaloCellCaloCellLArDigitLArDigitLArRawChannelLArRawChannel

CaloCellCaloCellTileReconstructionTileReconstruction


Tower ReconstructionTower Reconstruction

C C

C

CaloCell Collection

TowerBuilderTowerBuilder

T T

T

CaloTower Collection

T T

T


TowerBuilderTowerBuilder

Configuration AR = 0.025 x 0.025

Configuration BR = 0.1 x 0.1

Key B Key A


Cluster ReconstructionCluster Reconstruction Clustering AlgorithmsClustering Algorithms

Sliding Window (for EM and Hadronic Clusters)Sliding Window (for EM and Hadronic Clusters) Cone Algorithm (Fixed cone size around hottest cell)Cone Algorithm (Fixed cone size around hottest cell) Nearest Neighbour AlgorithmNearest Neighbour Algorithm

Clustering and needed Correction algorithms Clustering and needed Correction algorithms can be dynamically loadedcan be dynamically loaded

CaloClusterMakerCaloClusterMaker

Sliding WindowSliding WindowEnergyEnergy

CorrectionCorrectionPosition Position

CorrectionsCorrections

T TT


CaloCluster

E, E, , , SamplingSampling…………list<CaloCell*>list<CaloCell*>

C CC

CaloCell Collection


Comparison to Comparison to ATRECONATRECON


Combined ReconstructionCombined Reconstruction

egamma Recegamma Rec (JBH, H. Ma, S. R., A. R., M. W.) First version provides Cluster-Track match,Shower Shape, Isolation… (missing conversions)Output in standard ntuples

CaloCluster, CaloCluster, SimpleTrackSimpleTrack

egammaegamma

Jet RecJet Rec (A. Gupta, F. Merritt, P. Loch, M. Wielers)KT Algorithm implementation. Most work by Tile, LAr beginning to join in the effort

CaloObjectCaloObject

JetJet

tau Rectau Rec (L. Vacavant, I.H., F.P., S.R.)First version in 2.0.0 (Lund) based on Phys. TDR cutsEM Radius, EM Strips, Isolation, # tracksOutput in standard ntuples

CaloCluster, CaloCluster, SimpleTrackSimpleTrack

tau Objecttau Object

Missing ETMissing ET (B. Caron)First version for Lund Releasebased on CaloCell Energies only

CaloCellCaloCell

MissingETMissingET


User Feedback/ValidationUser Feedback/Validation Quality Assurance : Quality Assurance : (S. Albrand)(S. Albrand)

Some of the recommendation already implementedSome of the recommendation already implemented

Extensive comparison between Atrecon & AthenaExtensive comparison between Atrecon & Athena FairouzFairouz studies of B studies of B J/ J/ ( ( ) )

http://isnwww.in2p3.fr/atlas/fairouz/physics/athena.html Statistically same, per event differences being Statistically same, per event differences being

understoodunderstood

Validation of software requested on pre-selected physics processes by NEWNEW users to Athena.

Z ee M. Losty (TRIUMF) H E. Tournefier (Grenoble) tau analysis F. Paige, D. Cavelli Jets, MissingET B. Caron, J. Pinfold


Recent PlotsRecent Plots


-> -> analysis analysis (F. Ohlsson-Malek)


Shower Shape ComparisonShower Shape Comparison Atrecon-Athena in EM Sampling 2 (A. Radu, M. (A. Radu, M.

Wielers)Wielers)

R = E(3x5)/E(7x7) w = width (3x5) E = 20 GeV e-


Other DetailsOther Details Particle ID strategiesParticle ID strategies IKinematic InterfaceIKinematic Interface

Proposal by ATLFAST group needs review/adoptionProposal by ATLFAST group needs review/adoption Event Filter requirementsEvent Filter requirements Adoption of new framework featuresAdoption of new framework features

StoreGate, Data Links, PersistencyStoreGate, Data Links, Persistency Using Detector Description in ReconstructionUsing Detector Description in Reconstruction

Hardwired in code at presentHardwired in code at present work in progress to read from DB (MySQL, Objectivity)work in progress to read from DB (MySQL, Objectivity)

Persistency support (Objectivity, Root)Persistency support (Objectivity, Root) Documentation: Documentation:

http://atlas.web.cern.ch/Atlas/GROUPS/LIQARGON/software/Reconstrhttp://atlas.web.cern.ch/Atlas/GROUPS/LIQARGON/software/Reconstruction/uction/


ConclusionConclusion

A central framework that is evolving to provide robust A central framework that is evolving to provide robust supportsupport

The reconstruction design has been built over this The reconstruction design has been built over this frameworkframework

Much of the ‘Fortran’ code has been migrated.Much of the ‘Fortran’ code has been migrated. Validation ongoing, but results are promising.Validation ongoing, but results are promising.

It now paves the way for work in:It now paves the way for work in: optimizing and developing new algorithmsoptimizing and developing new algorithms Physics and Detector performance studiesPhysics and Detector performance studies

aspects of lar reconstruction s. rajagopalan atlas week june 4, 2001

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