ProtoDUNE-SPReconstructionSoftwareReviewandPerformance

LeighWhiteheadOnbehalfoftheprotoDUNE-SPDRAGroup

10/05/18

Introduction• Theseslidesprovideanoverviewofthematerialpresentedinthe

ProtoDUNE-SPreconstructionsoftwarereviewdocument

• Thereconstructionmustprovidetoolsforcalibrations,TPCanalysesandPDanalysis:• Efficientcosmicmuonreconstruction• T0measurementforasmanycosmicmuonsaspossible• CNNhittaggingforMichelelectronevents

• Thetalkfocusesontwomainparts:• Overviewofthealgorithmsinthereconstructionchain• Performanceofthosealgorithmscriticaltothepion-argoncrosssection

analysis

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ReconstructionChainOverview• TherearesixmainstepsintheTPCreconstructionchain

• Someofthesestepshavedifferentcomplimentaryapproaches

• Twostepsintheopticalinformationprocessing

• NB:thisfigureisdemonstrative,otherapproachessuchasWireCell gostraightfromTPCsignalsto3Dreconstruction

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TPCSignalProcessing HitFinding Clustering CNNHit

Tagging

TrackFinding +Vertexing

ShowerReco

OpticalHitFinding

OpticalClustering

TPCSignalProcessing• Thegoalofthesignalprocessingistoreconstructthedistribution

ofionisationelectronsarrivingoneachwireovertime• Providecleanwaveformsfromwhichtobeginhitfinding

• Currenttechniquebasedona1Dconvolution• ApplyFastFourierTransformtoisolatenoiseandsignalfrequencies

• Effectivelyrolesupallsourcesofsignalshaping(amplifiers,electronicsresponseetc)intoaGaussiansmearingfunction

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TPCSignalProcessing• MicroBooNE recentlymadeanimportantstepforwardusinga2D

convolution• ThismethodwillbeportedovertoprotoDUNE soon

• PossibleissuesforProtoDUNE:• Stickycodes:theseareincorrectadc valuesthatappearasspikes

inthewaveform• RepresentalossofinformationbutanewADCcodecanbeformedvia

interpolationfromneighbouringgoodcodes

• Non-linearityoftheADCs• Mustbedealtwithusingacalibrationscheme.

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HitFinding• Thehitfinding”GausHitFinder”algorithmsearchesforthe

numberofpeaksinawaveform

• AfterfindingeachoftheNpeaksthedistributionisfittedwithNGaussianfunctions

• EachoneoftheseNGaussianfitsformsthebasisofanindividualhitobject(recob::Hit)

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HitDisambiguation• ThewrappedinductionwiresoftheAPAsgiveanonone-to-one

mappingofanelectronicschannelIDtoawireID• EachchannelIDmapstoanumberofwireIDs(onbothsidesoftheAPA)

• WhilstprotoDUNEhasTPCsonlyononesideoftheAPAsthewiresarewrappedandanalgorithmmustbeusedtoidentifythecorrectwireIDforasignalonagivenchannelID

• ProtoDUNE-SPusesSpacePointSolverasthedefaultalgorithm...• 10xfasterthanthepreviousmethoddevelopedforthe35t• MoreaccurateinProtoDUNE(notthecasefortheFD)• Improvedandfastertrackingefficiencywithlinecluster+pma• Detailsoftheprocessonthenextslide

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SpacePointSolver• SpacePointSolveraimstoconvertthree2Dviewsintoasingle

collectionof3Dspacepoints

• Matchestripletsofwiresacrossthreeviewsmatchingcloselyintime– oftentherecanbemultiplecandidatetriplets• Resolvesambiguitiesbyminimisingthedifferencebetweenthepredicted

andobservedchargesontheinductionwires

• Designedasthefirststeptowardsafully3DreconstructionforFDneutrinointeractions

• ForProtoDUNEwewillinitiallyuseittoperformdisambiguation• Moreaccurateandfasterthantheaforementioneddisambiguation

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SpacePointSolver• ExampleofthealgorithmperformanceattheFD

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Clustering• WehavetwoclusteringapproachesasofMCC10:

• LineClusterandTrajCluster

• Bothmethodsaimtoformclustersusingashortline-likeseedclusterandsearchingforsimilarhitstoextendtheclustertoproduce2Dclustersofassociatedhits

• TrajClusterismorecomplexthanLineCluster• Canmatchtogethertheclustersfromthe2Dviewsinto3D• Tagsshower-likeclusters

• Pandora(seelater)hasitsownsetofclusteringalgorithms

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CNNHitTagging• Thehit-taggingCNNtakesthehitsfromtheclusteringstepas

input• Itclassifieseachhitastrack-likeorEM-like,andthenalsoashowMichel-

likeitis

• Itconsiderseachviewseparatelyandclassifieshitsineachviewinthesameway

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Track-like EM-like

CNNHitTagging• Exampleperformanceforbeamπ+ events

• ShowthetotalEM-liketaggedADCtotalfromtheCNNcomparedtothetruetotalEM-likeADC

• OutputfromtheCNNusedinnumerousplaces• Allowtrackingalgorithmstopurelyfocusontrack-likehits• Michel-likehitsusedfortheMichelelectronanalysis• EM-likehitsusedforelectronandπ+ reconstructionandanalyses

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1GeVπ+ 4 GeVπ+

Tracking- PMA• ProjectionMatchingAlgorithm(PMA)wasdevelopedasa3d

reconstructiontoolforparticletrajectoriesinICARUS

• Itnativelycreates3Dtrackobjectsbyminimisingthedistancetohitsinallthreeviewssimultaneously

• Italsoperformestrackvertexingallowingforthecreationofextendedandcomplexstructuresofinteractions

• TherehavebeensomeupdatesforthespecificchallengesofProtoDUNE...

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Tracking- PMA• Cathodestitching:

• Associatetrackseithersideofthecathodeandformasingletrack

• TheshiftrequiredinthedriftdirectiontodothisgivesthetrackT0

• NB:thisalsoworksforanodestitchinginthosegeometriesthatrequireit

• Cosmic-raytagging

• Usethehit-taggingCNNtoreconstructonlytrack-likeobjects

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Pandora• Pandoraemploysamulti-algorithmapproachtograduallybuild

upacompleteinteraction• UsedsuccessfullyonMicroBooNE

• Eventsareslicedintoregionsofinterestideallycontaininghitsfromasingleprimary• Thehitsintheseregionsarepassedthroughtworeconstructionchains:

oneoptimisedforcosmics,theotherforneutrinos

• InthecaseofprotoDUNE,theneutrinoreconstructionchainbecomesthebeamparticlereconstruction• Alongwiththeadditionofaspecificmodulethatre-organisesthefinal

interactiongiventhatthereisanincomingbeamparticleandnotaneutrinointeractionvertex

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Pandora

• PandorawillthendecidewhetheragivenslicecontainsabeamorcosmicparticleusingaBDT• Givescandidatebeamparticlesandcosmic-raysasoutput

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Test Beam Particle Creation: Reconstructed Parent Particle: !+ Vertex: Start Vertex Hits: !+

Daughter Particles: 4 x p, 2 x "+

2 x !- !+

p"+

p

p

!-

p

"+

Interaction Vertex

!+

Default Reconstruction Reconstructed Parent Particle: Neutrino Vertex: Interaction Vertex Hits: No Visible Hits

Daughter Particles: 4 x p, 2 x "+

2 x !-

1 x !+

Start Vertex

!-

10 cm

ShowerReconstruction• Pandoraproducesshowerobjectsaspartofthefullprimary

particleinteractiondescription

• TheEMShoweralgorithmtakesthePandoraoutputsandreconstructsfull3Dshowers• ItalsotakestheoutputfromtheCNNtorejectnonEM-likehits• Positionandmomentumfour-vectors• dE/dxintheinitialregionoftheshower– provideselectron/photonID

• DidnotrunaspartofMonteCarloChallenge(MCC)10• Testingcurrentlyunderwayandwillbere-introducedinMCC11

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CalorimetryandPID• ThecalorimetryalgorithmsarerequiredtoconverttheADCtoa

finaldE/dxforreconstructedtracks

• FirstlyaconversionfromADCtochargeisperformed• Accountforchargelossduetoimpurities• ProvidesdQ/dx

• InordertoconvertfromdQ/dxtodE/dxneedtoaccountforchargequenching:• ApplyBirk’sorthemodifiedBoxmodel

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CalorimetryandPID• ExamplesfromtheFD:

• BottomrightplotshowsalternativePIDmethodcalledPIDA

• PIDAusesdE/dxandresidualrangetoseparatespecies

• dE/dxcurvesoneofthefirstgoalsfromProtoDUNEbeamdata

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PIDA =1

N

Ri<30 cmX

Ri=0

✓dE

dx

◆

i

R

0.42i

CriticalPathforthePionAnalysis• TheprimaryphysicsgoalforprotoDUNE-SPisthemeasurement

oftheinclusivepion-argoncrosssection• SeeStefania’stalkfromthemorningsessionformoredetails

• Thealgorithmsexplicitlyrequiredforthisanalysisareasubsampleofthosepreviouslydescribed

• Weneed:• ReconstructedcosmicmuonswithT0 forcalibrations• Rejectionofcosmicraysandidentificationofπ± fortheanalysis

• Trackreconstructioniskeyhere

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Cosmic-rayTrackReconstruction• Weneedtoefficiencyand

accuratelyreconstructandidentifycosmicrays

• T0-taggedcosmics neededfordetectorcalibration

• Needtorejectasmanycosmics aspossibleforthebeamanalyses

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Reco T0 - True T0 (us)10− 8− 6− 4− 2− 0 2 4 6 8 100

2

4

6

8

10

12

14

Pandora T0

Reco T0 - True T0 (us)10− 8− 6− 4− 2− 0 2 4 6 8 100

2

4

6

8

10

PMA T0

Cosmic-rayMuonTagging- PMA• CosmicraystaggedinPMAusinganumberoftechniques

• MeasuredT0 incompatiblewithbeam• ReconstructedoutsidethedetectorindriftdirectionassumingT0 =0• Trackeither:

• CrossesTPCtoptobottom• CrossesTPCfromtoptofront/back• EntersTPCfromthetopandstops

• Integratedefficiency=70%• Analysislevelcutswillremovemore

ofthesecosmics

• Purity~93%– theT0 taggingmethodscanalsotagbeambackgrounds,butnotthesignalpartcilesweareinterestedin

• T0taggedcosmicsarecriticalforthedetectorcalibration

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Reconstructed track length (cm)0 100 200 300 400 500 600

Cos

mic

tagg

ing

effic

ienc

y

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Cosmic/BeamID- Pandora• TheProtoDUNE-SPversionofPandoraaimstolabeltheparticlesaseitherof

cosmicorbeamorigin

• NB:Ifaslicecontainsmoretruecosmichitsthanbeamhitsitisconsideredascosmicthuscausingtheapparentlowefficiencyinthebeamparticleplot• ThispurelymeansPandorafindstheseeventsambiguous• Thesearenotlostfordownstreamalgorithmsandanalyseswherebeam– TPCmatching

willreclaimmanyofthese.

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Number of Hits210 310

Effic

ienc

y

0.0

0.2

0.4

0.6

0.8

1.0

Bdt Beam Particle Id

Number of Hits210 310

Effic

ienc

y

0.0

0.2

0.4

0.6

0.8

1.0

Bdt Beam Particle Id

CosmicBeam

Integrated:72.3%

Integrated:94.5%

PionEntryPoint• Akeyelementofthisanalysisismatchingthebeamparticleto

thecorrecttrackinsidetheTPCdriftvolume• ThishasbeenstudiedusingbothPMAandPandora

• ThexandycomponentslookmostlythesamewithSCE,butwegeta20cm(!)shiftinz.Importanttocorrectforthis!

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3− 2− 1− 0 1 2 3Vx [cm]∆

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Entri

es/0

.5cm

PMA

Pandora

3− 2− 1− 0 1 2 3Vy [cm]∆

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Entri

es/0

.5cm

3− 2− 1− 0 1 2 3Vz [cm]∆

0

0.1

0.2

0.3

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Entri

es/0

.5cm

Summary• Thereconstructionsoftwareisingoodshape

• Itwillprovidetherequiredsamplesfortherequiredcalibrationsandtheprimaryphysicsgoal

• Thosetoolsrequiredforthepion-argoncrosssectionarethealgorithmsneededtoreconstructpionandmuontracks• Demonstratedthattheseareworkingwellinsimulation

• Thealgorithmsnotincludedinthecriticalpatharestillveryimportant• Neededforothersecondarygoals(π0,beamelectronsetc)• ImportantforthedeveloperstotesttheiralgorithmsonprotoDUNEdata

aheadofimplementingthemintheDUNEFD

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Cosmic/BeamID- Pandora• TheProtoDUNE-SPversionofPandoraaimstolabeltheparticles

aseitherofcosmicorbeamorigin

• NB:Ifaslicecontainsmoretruecosmichitsthanbeamhitsitisconsideredasalossofefficiency.Thisissomethingthatcanbereclaimedatanalysistime

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