Roadmap for Validation of E T miss

1. Roadmap for Validation of ETmiss Hadronic Calibration Workshop Lisbon June 09 • Before Collisions: Data Quality • Noise • Dead channels • Cosmic and cleaning cuts • 2009 data: First collisions • Surprises in data • Minbias • Dijets • From Basic to Refined EtMiss: • Use reco objects as soon as validated • Observables • 2010 data: 10-100 pb-1 • Zee, Zmumu • Neutrinofication • Ztau tau • Wlnu • ttbar • MET Tails in SUSY (next talk) JetEtmiss Data Preparation task force (Silvia, R. Teuscher)

2. MissingET reconstruction Event Data Model (EDM) and AlgTools structure provide high level of modularity:  this allows to implement a step by step procedure of increasing complexity for the commissioning of the EtMiss  implemented two main Algorithmsto handle two main approaches for EtMiss calculation and calibration:  Global Calibration (MET_Final) Refined Calibration (MET_RefFinal)  different levels of “descoping” for EtMiss reconstruction already tested in the reprocessings of the cosmics and single beam data during 08/09 Milano

3. MET_CorrTopo MET_Final METFinalTool MET_MuonBoy MET_Cryo EtMiss Global Calibration (MET_Final) (1) CaloCellContainer (2) CaloTopoClusters (3) CaloCalTopoClusters MET_TopoObj METtopoObjTool NO calib METCaloCellTool Cell Loop Loop on TC and backnavigate to TopoCells MET_LocHadTopoObj 2 noise cut METSelectorTool LocHad calib TopoCell CaloCell Can also use em or H1 now… Topo signal state available METCaloTool MET_Topo NO calib MET_Base NO calib MET_Calib MET_CorrTopo METCalibTool H1 calib H1 calib MET_LocHadTopo LocHad calib

4. Refined EtMiss Calibration (MET_RefFinal) • implementation in Athena is based on an association map • between reconstructed objects and their constituent CaloCells and/or TopoClusters.  the association map allows to remove overlaps at cell level The set of METRefTools which access/fill the association map for each reconstructed object: METRefEleTool METRefTauTool METRefJetTool METRefMuoTool METRefCellOutTool METRefCellOutTool : loop on all CaloCells in TopoClusters not associated to reco object fill the association map with: *CaloCell, *TopoCl, CaloCell weight calculate METRef_CellOut Each RefTool : loop on identified Reco Objects collections for each Reco Obj backnavigate to its CaloCells fill the association map with: *CaloCell, *RecoObj, CaloCell weight calculate METRef_obj METRef_Ele METRef_ METRef_Tau METRef_BJet METRef_Jet METRef_Muo METRef_CellOut + + + + + + + MET_MuonBoy + MET_Cryo = METRef_Final • cell weights depend on the type of the reconstructed object (e/, , b-jet, jet, m …) • particle identification driven by MissingET package jobOptions. •  each contribution is individually available in ESD/AOD, degrees of freedom in physics analysis Can be run also from AOD /overlap removal at cluster level…

5. < 1-few pb-1 data: in-situ EtMiss validation minbias/Jets evts Final Ex(y)miss Resol = p0 *  SumET  Minimum bias Resolution curve done with 100k evts • METbase: from all Cells with |E|> 2 noise • METtopo: from all Cells inside TopoClusters  J4 Resolution curve done with 250k evts MET_Topo  p0=0.56  no calibration applied MET_TopoCorr  p0=0.54 apply H1 calib MET_Final  p0=0.51 add cryostat correction MET_LocHadTopo_Final  p0=0.55  apply LocHad calib Plots produced using METPerformance package mantained by A. Yurkevic (Stony Brook)+Milano

6. Refined EtMiss Calibration • Electrons/photons (MET_RefEle, METRefGamma): Default Calib = EM Scale RefCalib = CalibHits based e/g calibration the different effects (sampling, material in front, longitudinal leakage, out of cone)are now separately corrected • include corrections for sampling, material in front, longitudinal leakage, BUT NOT the out-of-cone to avoid double counting  already available • Jets (MET_RefJet): Default Calib = H1-style LocHad RefCalib = apply jet scale if out-of-cone correction is not included to avoid energy double counting • MET_Muon: Needed input from calibration experts about how to treat the jet scale in MET. Checks using different cones for jets already started • non-isolated muons: using combined reconstructed muons but taking the momentum from the external muon spectrometer only • isolated muons: use combined tracks plus CaloMuons MuTag tracks to take into account also muons in crack regions respectively: |h| < 0.1, 1<|h| < 1.3 • To avoid energy double counting the muon energy deposited in calorimeter is not added in the Final MET calculation • For first dataa more simple approach is foreseen: no separation between isolated and non-isol, and use for ALL muons the combined reconstructed muons taking the momentum from the external muon spectrometer only (no problem of double counting in calos) still iterating with muon experts... Possible to reco Muon Term on the fly on AOD, can run directly in analysis jobs.

7. Refined EtMiss Calibration • Cells outside reco objects (MET_CellOut) Default Calib = H1-style LocHad = Local Hadron Calibration MiniJet = special calib for low pT depositions integrated in MET package from ObjMET: • build the MiniJet fromTopoClusters not belonging to any reco object: • Minijets  weights depend to the  / classification of the MiniJet (sampling calibration) • Rest  weights depend on the CaloRegion of the TopoCluster (Barrel, Endcap, FCal) (region calibration) Has to be improved Consistency problems between MiniJet and Jet calibration ? Jet group Particle lost because they do not reach calo  Try to correct/improve using track info Diagnostic plot: MET projected along perpendicular axis vs dileptonpt in Zee events The perpendicular axis is defined by the vectorial sum of the 2 leptons momenta. The parallel axis is placed at p/2 to the perpendicular axis. The perpendicular axis is more sensitive to the balance between the electons and the hadronic recoil E. Williams (Columbia)+Milano

8. (M. Consonni) New approach using TopoClusters to calculate the offset: • fit better in MissingET reco schema which is based on TC, respect to subtract the offset calculated from Tower • could be applied also at AOD level (tower are not available) • still negative bias after offset subtraction, understand how to be recovered. • implementation in MissingET package is ready M. Consonni (Nikhef)+Milano

9. Understanding of MET tails Missing or fake muons (Ketevi, muon experts) Jet punch-through: Punch-through detection criteria using MuonSpShowerContainer info (J. Lundberg Cern)  Will be implemented in MissingETPerformance package Jets in cracks:eta distribution of sub-leading reco jet in QCD events with reco EtMiss>100 GeV show peaks in calo cracks (D. Berge Cern) can correct using track jets? Track-MissingEt (Taiwan)

10. ETmiss • Nice summary of the current Emiss calibration flow. • Roadmap from the first collision to 100pb-1was presented • Minimum bias event -> Jet-jet -> W,Z • Common analysis tools for Et miss study (METPerformance Package). • A great achievement of this Workshop! • Still more detailed description is required, in order to access concerns such as; • No double counting? • Consistent handling of Jets, electron, muons? • Minijet – Jet seperation (calibration consistent?) K. Tokushuku for the panel members • No double counting problems with electrons and muons • Still open issue: understand how to treat jet energy scale in MET, help needed from calibration experts • MiniJet and Jet calibrations have complete different approaches:  problems of consistency, but MiniJet is NOT the default calib for MET_CellOut  new proposal for MET_CellOut calib is to use track info in minbias events to recover low pt particles lost upstream of calo