Measuring efficiency using 3 particle final state events · Measuring efficiency using 3 particle...

Measuringefficiencyusing3particlefinalstateevents

HollySzumila-VanceHPSCollaborationMeeting

3May2017

Outline:• RateeffectsandEcal-onlydata• 3particlefinalstateeventselection• Topologies• Efficiencies• Summary

50nA200nA300nA

Psum [GeV]

2016SVTdatahasratedependency

EffectisnotclearinEcal-onlyselection

50nA200nA300nA200nA150nA50nA

Ecal OnlySelection- 2015Run RunCurrent(nA) Fcup livetime Q(nc)

Q(nc)xlivetime

5749 30 0.97 14631 141935754 40 0.938 15330 14380

5755 60 0.87 17288 15041

5772 50 0.8822 333139 293895

• Allusedv7tb-Lat147trigger• 5749,5754haduniquepedestalsforspecifiedcurrent• 5755and5772used50nA pedestals

2015running

Looseselection(dominatedbyWABs):• E<0.8GeV• Timedifference<1.6ns• Pairs1• Triggertimewindow• 1clusterintop,1inbottom• 1clusterlefthalf,1clusterrighthalf

Fiducial

30nA40nA50nA60nA

Wab-beam-tri

Wab-beam-tri

30nA40nA50nA60nA

Thiswab-beam-triMCusesMG5

Fiducial

Here’sthesamelooseselectionIshowedinNovemberwherewab-beam-triwasusingMG4.

→Notverydifferentfromnow.

MC30nA40nA50nA60nA

MC30nA40nA50nA60nA

30nA40nA50nA60nA

Fiducial

30nA40nA50nA60nA

2015running

Tightselection(reduceWABs):• E<0.8GeV• Timedifference<1.6ns• Pairs1• Triggertimewindow• 1clusterintop,1inbottom• 1clusterlefthalf,1clusterrighthalf• clusterswithin+/-200MeV• Coplanar180+/- 10deg

wab-beam-tri

wab-beam-tri

Thiswab-beam-triMCusesMG5

Fiducial

MC30nA40nA50nA60nA

MC30nA40nA50nA60nA

Here’sthesametightselectionIshowedinNovemberwherewab-beam-triwasusingMG4.

→LowEsum inMG5looksmuchbetter!→HighEsum inMG5unchanged

3ParticleFinalStateEventSelection• Tracks:

• P<850MeV(toavoidFEE)• Trackscansharenomorethan3hitswithothertracks• GBLtracks(5+hits)• 3rd trackinfiducialregion(seenextslide)

• Clusters:• ClusterE<850MeV(toavoidFEE)• Energy-DistanceCut(shown2slidesfromnow)• Clustersintriggertimewindow[40,50]• Chooseclustersatleast¾crystalawayfromedge• Clusterenergysum>0.9GeV

• Track-ClusterMatching:• Matchingwithin10sigma,basedonposition

• Aftermatching,checkmatchedclustersareintime.Choosethebest,unmatchedclusterasonethatisintime,hassmallesttimedifference,andenergysumofallclusters<1.2GeV

• Pairs1trigger

3rd trackFiducialCuts,fromflatMCPx/Pz

Py/Pz

Px/Pz

Py/Pz

Px/PzPx/Pz

P[GeV] P[GeV]

electron

electron

positron

positron

Resultsoffinaleventselection

Energy-distancecutElectron,

3matchedtracks

Energy-distancecutPositron,

3matchedtracks

Psum ofTracks

Esum ofClusters

Considerthesetopologies:

e- (close),e+

e- (far)

e- (far),e+

e- (close)

e+

e- (close),e- (far)

• Disambiguatethee- clusterusingtheclusterpositioniny.

• Considereachofthesethreecaseswithe+top/bottom.

Tag andprobe(slideshows1topology):

e- (close),e+

e- (far)

• Considerallcombinationsandkeeptop/bottomseparate.

e- (close),e+

e- (far)

e- (close),e+

e- (far)

Tritrig-wab-beam-tri(wab-beam-trihadnotenoughstatistics)

ElectronTrackEfficiency

PositronTrackEfficiency

5772



Positronintop,alone

Positroninbottom,alone

5772



5772

WAB

WAB MC:Electron Efficiency

5772:Electron Efficiency

WAB MC:Positron Efficiency

5772:Positron Efficiency

WAB MC:Electron Efficiency

WAB MC:Positron Efficiency

Conclusions:• ThreeparticlefinalstateeventsprobablymostlyWABs• Efficienciescouldbysystematicallylow inregionsby5-10%• Don’tseehugetop/bottomdifference• Needtorunovermoredata• Difficulttofindclearcorrectionwith3prongevents• Beingabletovertex3trackscouldhelp(andusefultovertexanalysistail

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Measuring efficiency using 3 particle final state events · Measuring efficiency using 3 particle...

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