Leptons: e, , + systematic uncertainties Javier Fernandez On behalf of ATLAS, CDF, CMS and D0 collaborations TOP 2013 6 th International Workshop on

Leptons e + systematic uncertainties

Javier FernandezOn behalf of ATLAS CDF CMS and D0 collaborations

TOP 20136th International Workshop on Top Quark Physics

15 September Durbach Germany

ManuTe Bol (2010 rip) 231m

Tyrone BogUes

ttop quark

~1735 GeV

uup quark

~23 MeV

ldquoSize mattersrdquo

Leptons in top

in Spain soccer is not a trending topic anymorehellip

15 September 2013 J Fernaacutendez 3

Outline

bull The detectors

bull Trigger with leptons

bull Electrons

bull Muons

bull Taus

bull Systematics

bull Summary and conclusions

bull References

The detectors

Coverage

Tracking ||lt25

Tracking ||lt2

Tracking ||lt3

Tracking ||lt25

Leptons (general remarks)bull Impact on top physics efficiency QCD estimate amp modeling

bull Trigger largely based on leptons their presence helps in triggering

bull Excellent ID capabilitiesndash Use redundancy of sub-detectors for muonsndash Shower shapes HE conversion vetoes for electrons

bull Generally speaking ndash Fake electrons gamma or π0 + random overlapping track bremsstrahlung semi-leptonic b-jet

decays hadron decays in flighthellip Beware of conversionsndash Fake muons semi-leptonic b-jet decays hadron decays in flighthellipndash Muons have fewer fakes than electrons which leads to a smaller QCD fractionndash Taus usually considered as ldquoplainrdquo leptons in their e decay in hadronic decays tricky ID

bull Charge mis-identication ndash (p lt 1 TeV) sub-percent level ndash electrons at percent level

bull Z peak allows TampP methods for efficiencycalculations

Electron Triggersbull L1 based mainly on ECAL deposit

bull L2L3HLTEF full reconstruction and ECALTracker isolation (a must to keep sustainable rate)

bull Large eta acceptance but larger ET threshold

bull Efficiencies close to 95

bull Lowest unprescaled bit ndash ATLAS SingleIsoEle24 ( OR Ele60 +

Dilepton Triggers)ndash CMS SingleIsoEle27 (+ DiEle17_8 +

EleMu17_8 + Lower CrossTriggers)ndash Tevatron SingleEle18 (+ DiElectron)

Muon Triggersbull L1 Based on hits from fast muon

chambers

bull L2L3HLTEF full reconstruction matching reconstructed track to muon hits

bull CDF approach increase acceptance by taking muons from complementary triggers (MET+2jets) 30 gain Improved top sensitivity by 7

bull Efficiencies greater than ~90

bull Lowest unprescaled bit ndash ATLAS SingleIsoMu24 (+ Mu36 +

Dilepton triggers)ndash CMS SingleIsoMu24 (+ DiMuon17_8 +

MuEle17_8 + Lower CrossTriggers)ndash Tevatron SingleMu18 (+ DiMuon)

Wrt Muons passing L1

Tau triggersbull Different approaches

ndash Isolation ndash pT thresholdndash Jets with restricted (3)

number of tracks

bull More sofisticated algos at HLTEF

bull Efficiencies ~80

bull L1 11GeV HLTEF 20-30GeV

bull In tt in +jets 7TeVndash ATLAS b-jet Trigger +

4jetsgt10GeV (2 b-tagged)ndash CMS Jets + tau Filter

(pTgt40-45GeV)

Electron reconstructionbull Reconstruction

ndash combination of tracker and calorimeter information

ndash match track with clustersndash sliding window algorithm for

EM clustersndash keep conversion photons at

this point to ensure high efficiency

GSF tracking (instead of Kalman filter) used by default it takes into account bremsstrahlung energy losses

Electron IDbull MVA techniques combining

calorimeter variables ndash Improvement of IDndash Categories

bull Conversion veto afterwards

bull Efficiency also measured with TampP method

bull Good description dataMC very high efficiency recoId

Electron Energy scale amp Resolution

bull CMS From di-electron resonances resolution lt1-2 barrel lt4 endcap

bull ATLAS Syst unc about 1-15

Muon reconstruction amp IDbull Combine different information from

silicon tracking and muon systemsndash Can also match to MIP signature in

calorimeter

bull Muon categories usually divided by subdetector content into Tight (all) Medium and Loose (only muon chambers) categories

ndash Cosmics rejected by requirements on timing DCAIP using angular properties and acolinearity of central tracks negligible signal loss

ndash In flight decays () ldquokinksrdquo in central tracks DCA amp χ2 cuts

ndash Punch-through increased quality criteria

bull Measure lepton identification efficiencies with the Tag amp Probe

ndash Tag lepton Strict selection requirementsndash Probe lepton Relaxed selection not bias

bull Subtract combinatorial background with simultaneous fit for the probes passing and failing the selection requirements

Muon energy scale amp resolutionbull CMS Measurement dominated by

silicon tracker for PT lt200 GeVc

bull Low and medium ranges ([0-100] GeV) with di- resonances resolution lt1-2 barrel lt6 endcap

bull ATLAS Di-muon mass resolution for muons from Z boson decays using the combined muon momentum measurements performed in the inner detector and the muon spectrometer

bull Error bars are the sum of the statistical error and the absolute value of the change of the resolution when the fit range is reduced to m(μμ)[82 100 GeVc2]

Isolation and PU dependencebull CMS Using particle-based isolation

bull Cut on relative isolation in a cone with typically R = 03-04 relIso = (PCH+PNH+PPho) PT

bull Isolation requirements also included in lepton triggers

bull Pile up contributionndash Negligible for charged hadrons (vertexing)ndash Developed methods to correct for neutral particle

candidates Use global average energy density

bull ATLAS Isolation is optimized for low dependence on PU and high multijet background rejection

ndash Require ET (Rlt02) ndash Require PT (Rlt03) ndash Keep eff fixed at 90 by changing cut value in pT

and ndash Muons use PT dependent isolationndash Electrons use fixed-size cone absolute isolation

bull Achieve no PU dependence

Fakes (mis-ID) estimationbull Main source of background for analyses using

low Et leptons (mainly Tevatron)ndash Fake lepton mainly from jets containing πηκndash Other sources conversion CalEM penetration

bull Fake rates (in Tevatron)ndash Measured in jet samples (j20 j50 etc)ndash Electron ~1(5) in 10000 tight (loose) jetsndash Muon ~ 2 - 6 per 1000 tracks depending on pT

bull Fake rates (in LHC)ndash Depending on lepton criteria (~10-20)

bull Low fake rate leads to precision measurementndash Fake leptons cause major systematic error in WW

cross-section (CDF) contribute 70 of the error to the acceptance value

bull Methodsndash Fake electrons (anti-electron or jet-electron)ndash Using exclusive decays from kaons protons and

pionsndash Matrix method

bull Typical systematic uncertainties O(50)

Tau reconstructionbull 23 decays hadronically (into one or three

charged mesons predominantly a and potentially additional neutral )

bull Challenge reject hadronic jets (larger production rate) faking tau candidates

ndash Coordinate resolution of the calorimeter alone not enough to resolve them

bull CMS Using hadrons plus strip algorithm (takes into account the broadening in of calorimeter signatures due to early showering photons)

bull Candidates are required to satisfy isolation based identication using charged hadrons and photons within cone around the candidate

bull ATLAS seeded by jets with 1 or gt=3 tracksbull Various discriminants are used to remove jet and

electron fakes Performancendash jet rejection factor ~300 for 35 signal efficiencyndash electron rejection factor100-1000 for 50 signal

efficiency

bull Both Tevatron experiments demonstrated their ability to reconstruct pi0 using

ndash shower max detector (CDF) with coordinate resolution about 2-3 mm

ndash preshower (D0) similar resolution

Tau IDbull Use of MVA techniques

to divide in categoriesndash ATLAS BDTndash CMS NN (TaNC) and

Hadron plus Strips (HPS)ndash CDF cut-based approach

+ NNndash D0 NN

Efficiencies ~45-50

Tau energy scale and resolutionbull ATLAS Response curves as a

function of the reconstructed visible tau momentum for tau decays Resolution better than 25 uncertainty lt3

bull CMS Energy scale 1 with measured uncertainty better than 3

Tau mis-IDbull Major sources of jets that can fake hadronic

taus QCD W+jetsbull Fake probability falls with energy (mass cut)

ndash ATLAS below 6 up to 240GeVndash CMS below 3

bull Discrimination against electrons using MVA with efficiency lt2 (estimated with Z rarree)

bull Discrimination against muons with efficiency lt 02

bull Charged Misid Rate 1-2ndash CDF ~1 at 20 GeV 02 at 100GeV

CMS Preliminary

Systematics related to leptons

in TOP

analysis amp measurements

+ Systematic uncertainties

(in top measurements)

Caveatsbull Focused on main top measurements (mass

cross-section widths ratioshellip)bull Dilepton lepton+jets and tau channels only

for obvious reasonshellipbull Most of lepton systematics related to

ndash Efficiencies reconstruction identification Triggerndash Lepton momentumenergy scalendash Lepton momentumenergy resolutionndash LeptonDetector modeling

bull Main method smearing based on uncertaintity and propagation to yields templates fitshellipndash Fake Non-prompt lepton rates different issuendash PileUp relevant specially in LHC for year 2012 runs

LHC tt combination 7TeVbull ATLAS-CONF-2012-134 bull CMS PAS TOP-12-003

bull Detector model This class of uncertainty includes contributions due to uncertainties in the modelling of detector effects in the simulation

bull For ATLAS these include uncertainties in the electronmuon and jet identification efficiencies electron energy scale and resolution muon momentum scale and resolution jet resolution the calculation of the missing transverse momentum trigger and in the b jet identification in the all-jets channel

bull For CMS this class includes uncertainties in the modelling of efficiencies for lepton triggering reconstruction and identification in b tagging calibration and in the data-driven W+jets heavy flavour fractions determination which depends on it in the trigger in the all-jets channel in the hadronic decay modelling and in the effects of pileup

bull These uncertainties are taken as uncorrelated between the two collaborations

Tevatron cross-section combinationbull D0 Note 6363-CONF amp CDF Conf Note 10926

Tevatron mass combination 36-87fb-1arXiv13053929 CDF CONF NOTE 10976 D0 CONF NOTE 6381Lepton modeling (LepPt) The systematic uncertainty arising from uncertainties in the scale of lepton transverse momentum measurements It was not considered as a source of systematic uncertainty in the Run I measurements (Lumi in fb-1 values in GeVc2)

Summary of phase-space values amp uncertainties (not an exhaustive listhellip)Experiment Measurement Channel E (TeV) pT (GeV) max pT e (GeV) max e Syst () Lumi (fb-1)

ATLAS tt l+jets 7 20 25 25 247(no gap) 01-25 47ATLAS tt Dilepton 7 20 25 25 247(no gap) 22-26 07ATLAS tt +jet 7 gt 40 25 - - 2-5 167ATLAS tt l+jets 8 40 25 40 247(no gap) 24-47 58ATLAS Mass l+jets 7 20 25 25 247(no gap) 0 104ATLAS Mass Dilepton 7 20 25 25 247(no gap) 002-006 47ATLAS SingleTop tW Dilepton 7 25 25 25 247(no gap) 5-7 205

CMS tt l+jets 7 35 21 35 25 2-3 23CMS tt Dilepton 7 20 21 20 25 03-17 23CMS tt +jet 7 gt 45 23 - - 7-9 39CMS tt l+jets 8 26 21 30 25 24-28 28CMS tt Dilepton 8 20 24 20 25 03-25 24CMS Mass l+jets 7 30 21 30 21 002 5CMS Mass Dilepton 7 20 24 20 24 008 5CMS SingleTop tW Dilepton 7 20 24 20 25 1-2 49CDF Mass l+jets 196 20 11 20 11 001 87CDF Mass Dilepton 196 20 11 20 20 017 56CDF Mass +jet 196 gt25 20 - - 011 22CDF tt l+jets 196 20 06 20 11 13 46CDF tt Dilepton 196 20 11 20 20 22 88CDF tt +jet 196 gt25 20 - - 25 22CDF tt l+ 196 8 15 8 11 05-30 9CDF SingleTop (t-s) l+jets 196 20 15 20 16 1-7 75CDF Top Width l+jets 196 20 15 20 16 13 87D0 Mass l+jets 196 20 20 20 11 009 36D0 Mass Dilepton 196 15 20 15 25 (no gap) 011-022 54D0 tt Dilepton 196 15 20 15 25 (no gap) 15-30 54D0 tt l+jets 196 20 20 20 11 06-15 53D0 tt +jet 196 gt10 25 - - 042 1D0 tt l+ 196 20 18 15 11 27-75 12D0 SingleTop (t-s) l+jets 196 20 20 20 11 3-7 Trigger 97D0 R(WbWq) Dilepton 196 15 20 15 25 (no gap) 02-04 54

Summary and conclusionsbull Leptons in top measurements drivedriven by TriggerOffline thresholds

ndash 18GeV SingleLepton HLT Offline cuts 15-20GeV Tevatron ndash 24GeV SingleLepton HLT Offline cuts 20-40GeV LHC

bull Affecting TOP in LHC ndash Muon PT resolution is ~1-2 ECAL resolution ~1ndash Efficiencies amp ID larger than 90 low fake probabilities(Tevatron10-3-10-4LHC larger)ndash Mass measurements less affected (lt03) by lepton systematics than cross-section

measurements (up to 6)ndash aus Still room for improvement (syst up to 9) Fakes below 3

bull Explore l+ channel as Tevatron

bull Lepton systematics not a real issue (compared to b-tag and jet ones see next talk) in Tevatron and LHC RunI buthellip

bull hellipLHC RunII (and beyond) will force to rise Trigger lepton thresholds to cope with luminosity levels

ndash Kinematical phase space reduced (SingleLepton HLT ~30GeV) rarr offline 40-50GeVndash Forced to use cross or (even worse) prescaled triggers which might lead to larger

systematicsndash Must deal (even more) with the effects from extra minbias events (PU) in isolation

References (I)For most up to date results consult the webpagestwikis

bull httpstwikicernchtwikibinviewAtlasPublicTopPublicResultsbull httpstwikicernchtwikibinviewAtlasPublicMuonPerformancePublicPlots bull httpstwikicernchtwikibinviewAtlasPublicElectronGammaPublicCollisionResults bull httpstwikicernchtwikibinviewAtlasPublicTauPublicCollisionPlots bull httpstwikicernchtwikibinviewAtlasPublicMuonTriggerPublicResults bull httpstwikicernchtwikibinviewAtlasPublicEgammaTriggerPublicResults bull httpstwikicernchtwikibinviewAtlasPublicTauTriggerPublicResults

bull httpstwikicernchtwikibinviewCMSPublicPhysicsResultsTOP bull httpstwikicernchtwikibinviewCMSPublicPhysicsResultsMUO bull httpstwikicernchtwikibinviewCMSPublicPhysicsResultsEGM bull httpstwikicernchtwikibinviewCMSPublicPhysicsResultsPFT bull httpstwikicernchtwikibinviewauthCMSPublicL1TriggerDPGResults

bull httpwww-cdffnalgovphysicsnewtoptophtml

bull httpwww-d0fnalgovRun2Physicstoptop_public_web_pagestop_publichtml

bull httptevewwgfnalgovsingleTopbull httptevewwgfnalgovtop

References (II)bull LHC comb ATLAS-CONF-2012-134 CMS PAS TOP-12-003 Mass ATLAS-CONF-2012-095 CMS PAS TOP-12-001

bull Electrons ATL-COM-PHYS-2012-783 ATL-COM-PHYS-2011-1637 ATL-COM-PHYS-2012-259 ATL-COMPHYS-bull 2012-260 ATL-COM- PHYS-2012-782 ATL-COM-DAQ-2011-032 ATL-COM-DAQ-2012-146 ATL-COM-PHYS-2012-1668bull Muons ATL-COM-PHYS-2012-716 ATL-COM-MUON-2013-006 ATL-COM-PHYS-2013-340 ATL-COM-MUON-2013-015bull Taus ATLAS-CONF-2011-113 ATLAS-CONF-2012-054 ATLAS-CONF-2012-142 ATLAS-CONF-2013-044bull ATLAS tt 7TeV combination ATLAS-CONF-2012-024bull ATLAS tt l+jets 7TeV ATLAS-CONF-2012-131bull ATLAS tt dilep 7TeV JHEP 1205 (2012) 059bull ATLAS tt tau 7TeV Eur Phys J C 73 3 (2013) 2328 bull ATLAS tt l+jets 8TeV ATLAS-CONF-2012-149bull ATLAS tt differential l+jets Eur Phys J C (2013) 73 2261 bull ATLAS Mass l+jets 7TeV EurPhysJ C72 (2012) 2046bull ATLAS Mass dilep 7TeV ATLAS-CONF-2013-077 bull ATLAS tW 7TeV Phys Lett B 716 (2012) 142-159bull ATLAS Single top t-channel 7TeV Phys Lett B 717 (2012) 330-350bull ATLAS Single top t-channel 8TeV ATLAS-CONF-2012-132

bull Muons CMS MUO-10-004 CMS MUO-11-001bull Electrons CMS-PAS-EGM-10-004 CMS-PAS-EGM-10-001 CMS-PAS-EGM-11-001bull Taus CMS-PAS-TAU-11-001bull CMS tt 7TeV combination CMS PAS TOP-11-024bull CMS mass dilep 7TeV Eur Phys J C72 (2012) 2202 bull CMS tt l+jets 8TeV CMS PAS TOP-12-006 bull CMS tt dilep 8TeV CMS PAS TOP-12-007bull CMS tt dilep 7TeV JHEP 11 (2012) 067bull CMS tt tau 7TeV arXiv13015755bull CMS tt l+jets 7TeV Phys Lett B 720 (2013) 83bull CMS tt differential dilep amp l+jets 7TeV arXiv12112220bull CMS tt differential dilep 8TeV CMS PAS TOP-12-028bull CMS tt differential l+jets 8TeV CMS PAS TOP-12-027 bull CMS tW 7TeV Phys Rev Lett 110 (2013) 022003 bull CMS Single top t-channel 7TeV JHEP 12 (2012) 035bull CMS Single top t-channel 8TeV CMS PAS TOP-12-011

bull Tevatron mass combination FERMILAB-CONF-13-164-PPD-TD (arXiv13053929 [hep-ex])bull Tevatron x-section combination CDF Conf Note 10926 D0 Note 6363-CONF

Backup

CDF Dilepton cross sectionbull arXiv13047961bull The background from jets misidentified as leptons is estimated by using data events with exactly

one identified lepton and additional lepton candidates that satisfy less restrictive identification criteria The probability that a lepton-like candidate is reconstructed as a lepton is parametrized in terms of the candidatersquos transverse energy and isolation and measured in large samples of events triggered by the presence of at least one jet Misidentified leptons are modeled by applying these probabilities as weights to data events with only one high transverse-energy reconstructed lepton and a second electron-like or muon-like candidate To remove events with two leptons from this sample the lepton-like candidate is required to fail at least one lepton identification requirement The misidentified-lepton events are required to meet all event selection requirements when treating the lepton-like candidates as the second lepton in the event The uncertainty on the misidentified-lepton background model is dominated by the differences observed between identification rates determined in jet samples triggered by jets with ET greater than 20 50 70 or 100 GeV

bull A common systematic uncertainty for signal and simulatedbackground estimates comes from the uncertainty on the lepton identification correction factors which is measured to be 22

CDF l+jets mass

bull Phys Rev Lett 109 152003 (2012) bull We estimate systematic uncertainties due to the

lepton energy and momentum scales by propagating shifts in electron energy and muon momentum scales within their uncertainties

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

FERMILAB-PUB-11-240-E

Trigger EfficiencyThe MC events used in this analysis have associated weights to simulate the effect of trigger efficiencies To evaluate the effect of the uncertainties in these weights on the top-quark mass we repeat the ensemble studies onall tmacrt MC samples with the weights set to unity rederive the mt calibration and apply it to the data to extract mt The result is found to shift by minus001 GeV

Lepton Momentum ScaleA relative difference in the lepton momentum scale between data and MC can have a systematic effect on mt To evaluate this we first determine the size of the discrepancy and correct the scale of one tmacrt MC sample Ensemble studies are repeated on the corrected sample and the mean of the extracted mt is found to shift by 017 GeV relative to the default sample

D0 dilepton mass

bull Phys Rev Lett 107 082004 (2011)

D0 dilepton cross-sectionbull Physics Letters B 704 (2011) 403ndash410bull To estimate the uncertainty in the trigger efficiency we

use events selected with the same criteria as the tmacrt signal but without jet requirements In all four channels this selection is dominated by Zγ events We compute the ratio of the expected and observed number of events for two cases when both leptons are allowed to fire the trigger or when only one lepton is allowed to fire the trigger The difference in these ratios is used to estimate the uncertainty on the trigger efficiency

D0 l+jets cross-section

bull PRD 84 012008 (2011)

D0 tau+jets amp ltau cross-section

bull PRD 82 071102(R) (2010)bull D0 note 5607-CONF

ATLAS tt l+jets 7TeV

bull ATLAS-CONF-2012-131

CMS 7TeV mass in dilepton 5fb-1

bull Eur Phys J C72 (2012) 2202

ATLAS tt(hadronic)+jets 17fb-1 7TeVbull Eur Phys J C 73 3 (2013) 2328 bull Uncertainties on the simulation of the detector response are taken into

account using dedicated studies of the reconstructed physics objects (electrons muons jets EmissT ) The uncertainty due to mismodelling of the lepton veto is estimated using the uncertainties on the muon and electron reconstruction efficiencies determined from independent data samples and is found to be negligible

bull As the tauelectron template is taken directly from MC-simulated t macrt events the systematic uncertainties on this template are taken from estimates of the mismodelling of the simulation The dominant contributions come from variations in the amount of ISRFSR in the simulation (1 ) the modelling of the pile-up (1 ) and the statistical uncertainties (1 ) Uncertainties on the track reconstruction efficiencyjet energy scale and the ratio of τ had to electrons are found to be negligible

ATLAS tt l+jets 8TeV 58fb-1

bull a reconstructed electron with ET gt 40 GeV or muon of pT gt 40 GeV matching the corresponding

bull high level trigger object

bull bull no second lepton (reconstructed electron with ET gt 25 GeV or muon with pT gt 25 GeV)

bull CMS PAS TOP-12-007bull Muonbull candidates are reconstructed using a particle flow (PF) technique [13] and are required to havebull a transverse momentum pT gt 20 GeV and a pseudorapidity jhj lt 24 and to have consistentbull hits in the tracker or muon systems For selected muon candidates a cone of DR lt 04 is constructedbull around the candidate direction and the energy collected inside this cone excludingbull the lepton candidate contribution projected onto the plane transverse to the beam is computedbull using the PF objects In this procedure all charged PF candidates which are not associated tobull the main primary vertex are assumed to come from pileup events (PU) and are not accountedbull for The isolation has been also corrected for the PU neutral particles in the cone A ratio ofbull this sum to the transverse momentum of the lepton candidate defines the relative isolation discriminantbull Irel The candidate is considered to be non-isolated and is rejected if the value of Irelbull is above 020 for the muon The isolation selections are optimised using tmacrt MC eventsbull Electron candidates [14] are reconstructed with the PF algorithm starting from a cluster of energybull deposits in the crystals of the electromagnetic calorimeter which is then matched to hitsbull in the silicon tracker and is used to initiate a special track reconstruction algorithm which accountsbull for energy loss through bremsstrahlung Electron candidates are required to have pT gtbull 20 GeV and jhj lt 25 Reconstructed electrons must pass the electron identification made bybull a multivariate analysis (MVA) technique particularly a boosted decision trees which is basedbull on shower shape and track-cluster matching kinematic properties and quality of the tracksbull among others The electron ID requires an MVA discriminant larger than 01 and combines anbull optimal compromise between a large efficiency for signal (gt99) and a resonable rejection ofbull backgrounds ( 58) The distance of the closest approach in the plane to the beam line shouldbull also be less than 400 mm bull Electron candidates within DR =bull pbull Df2 + Dh2 lt 01 of a muon are rejected to remove electronbull from muon inner bremsstrahlung Electron candidates consistent with photon conversions arebull 3bull also rejected Details of the electron identification and quality requirements can be found inbull [1] As the muons also the electrons are required to be isolated The electron candidate isbull considered to be non-isolated and is rejected if the value of Irel is above 015 when using a conebull of DR lt 03bull The performance of the lepton isolation and identification selection is tested on lepton candidatesbull in Z events For both muons and electrons the isolation and identification selectionbull efficiency is fairly independent of pseudorapidity and falls slightly at lower momenta Thebull isolation selection efficiencies in Z events in data are estimated as a function of lepton pT andbull h and an overall good agreement with the value in simulation is found rescaling pT and hbull spectra in events with a Z boson to match the one in tmacrt MC events the data-to-simulation scalebull factors are 09790020 09930020 and 09860014 for the e+e1048576 m+m1048576and em channelsbull respectively

CMS tt dilepton 8TeV 24fb-1

bull CMS PAS TOP-12-006 bull Muons are required to have abull good quality track with pT gt 26 GeV and pseudorapidity jhj lt 21

Electrons are identifiedbull using a combination of the shower shape information and track-

electromagnetic cluster matchingbull [19] and required to have pT gt 30 GeV and jhj lt 25 with the

exclusion of the transitionbull region between the barrel and endcap electromagnetic calorimeter

144 lt jhj lt 157 Electrons coming from photon conversions are vetoed

bull Events with more than one electron or muon candidate with relaxed requirements are vetoed

bull in order to reject Z boson or top-quark-pair decays into dileptons No explicit requirement is

bull applied on the missing transverse energy

CMS tt l+jets 8TeV 28fb-1

CMS tt(hadronic)+jets 39fb-1 7TeV

bull arXiv13015755

ATLAS tt diferential 7TeV 205fb-1 l+jets

bull Eur Phys J C (2013) 73 2261 bull Electron candidates are defined as energy deposits in thebull EM calorimeter associated with well-reconstructed tracks ofbull charged particles in the ID The candidates are required tobull meet stringent identification criteria based on EM showerbull shape information track quality variables and informationbull from the transition radiation tracker [40] All candidates arebull required to have ET gt 25 GeV and |ηclu| lt 247 where ηclubull is the pseudorapidity of the EM calorimeter cluster associatedbull with the electron Candidates in the transition regionbull between the barrel and end-cap calorimeters 137 lt |ηclu| ltbull 152 are rejectedbull Muon candidates are reconstructed by combining trackbull segments in different layers of the muon chambers Suchbull segments are assembled starting from the outermost layerbull with a procedure that takes material effects into account andbull are then matched with tracks found in the ID The candidatesbull are then re-fitted exploiting the full track information frombull both the muon spectrometer and the ID and are required tobull have pT gt 20 GeV and |η| lt 25

bull Muon and electron trigger reconstruction and selection efficienciesbull are measured in data using Z and W decays and incorporatedbull into the simulation using weighted events Eachbull simulated event is weighted with the appropriate ratio (scalebull factor) of the measured efficiency to the simulated one Thebull uncertainties on the scale factors are estimated by varyingbull the lepton and signal selections and background uncertaintiesbull For lepton triggers the systematic uncertainties are about 1 The same procedure is used for lepton momentumbull scale and resolution scale factors resulting in uncertaintiesbull of 1ndash15 The corresponding scale factor uncertaintiesbull for electron (muon) reconstruction and identification efficiencybull are 1 (05 ) and 3 (05 ) respectively

CMS tt differential 7TeV 5fb-1

bull arXiv12112220

CMS tt differential 8TeV 5fb-1bull CMS PAS TOP-12-027 (l+jets)bull The efficiencies of the single-electron and single-

muon triggers are determined using the ldquotag and- proberdquo method with Z-boson event samples A dependence on the pseudorapidity and the transverse momentum of the muon and the electron of a few percent is observed and thus two-dimensional scale factors are derived The lepton identification and isolation efficiencies for the `+jets channels obtained with the tag-and-probe method agree well between data and simulation so that corrections very close or equal to unity are applied The systematic uncertainties are determined by shape-dependent variations of trigger and selection efficiencies within their uncertainties

bull CMS PAS TOP-12-028 (dilepton)bull The electron candidates are required to have a

transverse energy ET gt 20 GeV and pseudorapidity jhj lt 24 as reconstructed from a combination of the track momentum at the main interaction vertex and the corresponding energy deposition in the ECAL A relative isolation criterion Irel lt 015 is required where Irel is defined as the sum of the transverse momenta of all neutral and charged reconstructed particle candidates inside a cone around the electron in h 1048576 f space of DR P (Dh)2 + (Df)2 lt 03 divided by the pT of the electron Muon candidates are reconstructed using the track information from the silicon tracker and the muon system They are required to have pT gt 20 GeV and jhj lt 24 Isolated muon candidates are selected if they fulfill Irel lt 015 within a cone of DR lt 03 around the muon

tW 7TeV

bull ATLAS Phys Lett B 716 (2012) 142-159

Lepton pTgt25 ||lt247 (e) ||lt25 ()

bull CMS Phys Rev Lett 110 (2013) 022003

t-channel single top 8TeVbull CMS PAS TOP-12-011bull Muons with a transverse momentum pT of 26 GeVc a pseudo rapidity jhj lt 21 and

with isolationbull single-muon trigger efficiency and muon reconstructionbull efficiency are estimated with a ldquotag and proberdquo method from DrellndashYanbull data The uncertainty on such efficiencies has been conservatively taken in a way tobull cover the effect of the different kinematics in DrellndashYan data and in our single-topbull enriched samples as well as the dependence of the efficiencies from the pileupbull Muon trigger + reconstruction - 41 + 40 pb (- 51 + 51 )bull ATLAS-CONF-2012-132bull Electron candidates are reconstructed using a cluster-based algorithm and are

required to have ET gt 25 GeV and |ηcl| lt 247 where ηcl denotes the pseudorapidity of the calorimeter cluster Clusters falling in the calorimeter barrel-endcap transition-region corresponding to 137 lt |ηcl| lt 152 are ignored

bull pT gt 25 GeV and |η| lt 25 are considered Selectedbull muons must additionally satisfy a series of cuts on the number of track hits present in

the various trackingbull sub-detectors Muon candidates are also required to be isolated

Extended muon coverage in CDF

ManuTe Bol (2010 rip) 231m

Tyrone BogUes

ttop quark

~1735 GeV

uup quark

~23 MeV

ldquoSize mattersrdquo

Leptons in top

in Spain soccer is not a trending topic anymorehellip

Outline

bull The detectors

bull Electrons

bull Muons

bull Taus

bull Systematics

bull References

The detectors

Coverage

Tracking ||lt25

Tracking ||lt2

Tracking ||lt3

Tracking ||lt25

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Outline

bull The detectors

bull Electrons

bull Muons

bull Taus

bull Systematics

bull References

The detectors

Coverage

Tracking ||lt25

Tracking ||lt2

Tracking ||lt3

Tracking ||lt25

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

The detectors

Coverage

Tracking ||lt25

Tracking ||lt2

Tracking ||lt3

Tracking ||lt25

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Coverage

Tracking ||lt25

Tracking ||lt2

Tracking ||lt3

Tracking ||lt25

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

chambers

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

number of tracks

(pTgt40-45GeV)

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

calorimeter

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

efficiency

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

+ NNndash D0 NN

Efficiencies ~45-50

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

CMS Preliminary

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

in TOP

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

Backup

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

CDF l+jets mass

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

CDF dilepton mass

bull PRD 83 111101(R) (2011)

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

D0 l+jets mass

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

D0 dilepton mass

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull PRD 84 012008 (2011)

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv13015755

bull arXiv12112220

tW 7TeV

bull arXiv12112220

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bull arXiv12112220

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Documents

Leptons: e, , + systematic uncertainties Javier Fernandez On behalf of ATLAS, CDF, CMS and D0 collaborations TOP 2013 6 th International Workshop on