Electroweak Physics with CDF
Explore Electroweak Physics with CDF Collaboration at EPS 2003, covering Tevatron upgrades, precision measurements, and Boson signatures with detailed analyses and future perspectives.
Electroweak Physics with CDF
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Presentation Transcript
Electroweak Physics with CDF Antonio Sidoti University of Pisa and INFN For the CDF Collaboration EPS - Aachen 18 July 2003 • Outline: • The Tevatron and CDF Upgrade • Ewk Physics: • Baseline Measurements (W/Z) • Precision Measurements • Perspectives Aachen EPS03
Tevatron Booster Recycler CDF DØ Main Injector Fermilab Tevatron Upgrade (RunII) s RunI = 1.8 TeV Now s RunII = 1.96 TeV • New Main Injector: • Improve p-bar production • Recycler ring: • Reuse p-bars Not used yet! Aachen EPS03
Tevatron Performances • Lum at RunI: 110 pb-1 • 2003 Goals: • ~200 pb-1 for Fall • 10 pb -1/week by the end of the year • Achieved • ~9.2 pb-1 best week RunII Integrated Luminosity (pb-1) Weekly Integrated Luminosity (pb-1) 5.1031 3.1031 Peak Luminosity Used for today’s measurements 1.1031 Aachen EPS03
CDF RunII Detector • From RunI: • Solenoid • Muon system • Central Calorimeter Polar angle q • For RunII: • Front-end DAQ • Trigger • Track (L1) and Displaced Track (L2) • New Silicon Tracker (8 Layers) (|h|<2) • Central Outer Tracker • TOF • Plug Calorimeters • Extended Muon Coverage Electron Id up to |h|~2.8 Muon Id up to |h|~1.5 Aachen EPS03
Electroweak Physics at CDF: RoadMap W/Z Cross section (e,m,t,n). Central, Forward Regions Standard High PTProbes: Check Efficiencies, Backgrounds… Beyond SM Precision Electroweak Measurements at ~2TeV AFB Z Asymmetry G(W)Width • Z’ Resonances • New Interactions • Di-Boson Couplings W Asymmetry DiBoson Cross Section Universality W Mass SM Higgs Mass Constraint Aachen EPS03
Neutrinos: Large Missing Energy Only Transverse (ET or Met) Boson Signatures at CDF Electron: EM Calorimeters High Pt (Track) Isolated Muons: Muon Detectors High PT Isolated Z Signature: Two Isolated Leptons (diff charge) W Signature: Isolated Lepton and ET Aachen EPS03
Events Back. •B(W-->ll) (nb) 6% 2.64±0.01stat±0.09sys±0.16lum e 38625 11% 2.64±0.02stat±0.12sys±0.16lum 21599 W Cross Sections(e,m) Electron-Channel • Clean Signature • High ET • Isolated lepton • Missing ET • High & S/B Muon-Channel Aachen EPS03
W Cross Sections (t) th = narrow isol. jet + low trk mult. (1 or 3) + M(vis)<Mt Hadronic tau decays Lepton Universality s.BF(W->tn)=2.620.07(stat) 0.21(syst) 0.16(lum)nb Aachen EPS03
Clean Signature • Two High ET Isolated lepton • Opposite Charge • High & S/B Events Back. •B(Z-->ll) (pb) 267±6stat±15sys±16lum 1830 0.6% e 1631 0.9% 246±6stat±12sys±15lum Z Cross Sections(e,m) Muon Channel Electron Channel Aachen EPS03
Z Cross Section (t) Triggering on t from hadronic decay Clear Z ehsignal Can be our calibration sample Work in Progress for Cross Section Measurement Aachen EPS03
W Cross Section Measurements Z Cross Section Measurements s(ppW tn) s(ppW mn) s(ppW en) s(ppZ mm) s(ppZ ee) combined sW B(W l)= 2.640 ±0.012stat ±0.093syst ±0.158lum nb combinedsZ B(Z ll)= 251.5 ±4.3stat ±10.6syst ±15.1lum pb s(pp->W)Th@1.96 TeV=2.731 0.002(Th) nb(NNLO), Stirling et al, Phys Lett B531, (2002) Aachen EPS03 s(pp->Z)Th@1.96 TeV=252.1 8.8(Th) pb(NNLO)
From R to G(W) s.BF(W->lvl) R= s.BF(Z->ll) s(pp->W) G(Z) G(W->lnl) R= s(pp->Z) G(Z->ll) G(W) CDF (e): 9.880.24(stat)0.44(syst) CDF(m):10.690.28(stat)0.31(syst) CDF(e+m):10.690.28(stat)0.31(syst) CDF G(W) Measurement • Larger systematic uncertainties: • Detector Simulation (e) • Background Estimates(e-m) • Lepton ID (e-m) G(W)CDF=2146 78 MeV G(W)SM=2092.1 2.5 MeV Aachen EPS03
Extending geometric acceptance of Leptons. • Looking in the Forward regions (High |h|). • Towards Cross Section Measurements: • Establishing Baseline Selection • Trigger and ID efficiencies • Background Studies Extending Detector Acceptance Muon Channel(~0.6<|h|<1.0) i.e. “How to increase sample without increasing Luminosity” Aachen EPS03
Electron Channel 1.1<|h|<2.8 Combining Plug Calorimetry and Forward Tracking Z Boson W Boson Aachen EPS03
Sensitivity to u/d fraction in proton • Constraints on PDF • Smaller Uncertainty from PDF • in highPT EWK and Top Physics Towards W Charge Asymmetry PDF Sensitivity • Charge ID and high |h| coverage Work in Progress Aachen EPS03
Z Forward Backward Asymmetry SM Contributions Beyond SM(Z’,New Interactions) • Probing (Unique at Tevatron): • Z/g* Interference in High Invariant Mass Region (far from Z-pole) Consistent with SM Aachen EPS03
e + m Process: pp->Wg->lnlg Events Back •B(Wl) (pb) e 43 33% 17.2±3.8stat±2.8sys±1.0lum e + m 29% 19.8±4.5stat±2.4sys±1.2lum 38 SM @s=1.96TeV 18.7 ± 1.3 DiBoson Production:Wg • DiBoson Coupling Measurements: • Probe ewk boson self-coupling • Sensitivity to physics BSM(Anomalous Couplings) • Statistically Limited • One High-PT lepton(e,m) • One Photon(DR(g,l)>0.7) • Large Missing ET Aachen EPS03 Consistent with SM
Process: pp->Zg->llg Events Back. •B(Z-->ll) (pb) e 11 4.6% 5.5±1.7stat±0.6sys±0.3lum 14 4.0% 6.0±1.6stat±0.7sys±0.4lum DiBoson Production:Zg • Two High-PT Leptons(Opposite sign) • One Photon (DR(l,g) >0.7) •B(Z-->ll)SM= 5.4 ± 0.4pb Consistent with SM Aachen EPS03
pp->WW->ll’nn’ (l=e,m) Statistics Limited Step for SM Higgs Searches Diboson Cross Sections: WW • Selection: • Two High-Pt Isolated Central Leptons(Opposite Charge) • Large Missing ET • Veto Z production and Jets Bkg 1.530.64 WW->Dil 2.790.62 2 Events observed Main Backgrounds: DY, tt,WZ,Fakes Aachen EPS03
Baseline Electroweak Measurements Re-established • Electroweak Precision Measurement Program • Exploiting larger detector acceptance • Work in progress on dataset with the largest (beyond RunI ) integrated luminosity datasets Consistent with SM Conclusions Aachen EPS03
Backup Tevatron Lum at RunI ~110 pb-1 s RunI = 1.8 TeV Now s RunII = 1.96 TeV Aachen EPS03
=1 =2 =3 CDF Detector Aachen EPS03
a: selection criteria for pp coll. ma: #int/Bunch Crossing (BC) fBC: BC Frequency spp: pp inelastic cross section :Efficiency of CLC “0” hits #hits #part Luminosity Measurement at CDF • Luminosity (L) from CLC (Cherenkov Luminosity Counters): • Discriminating primary (from ppbar)-secondary particles • Time resolution Well adapted for high-L collider Increasing Lum. Uncertainty manly from: ea= MC simulation. spp = 60.41.4 mb (measured by CDF) mclc: Different definitions Systematic uncertainty ~5% Aachen EPS03
th tl Triggering on Taus (hadronic) pTseed> 5 GeV/c Tau Cone Isolation Cone Z pTl > 8 GeV/c ee, e, , eh, h Aachen EPS03
Backup AFB Aachen EPS03
DiBoson(Wg,Zg) Wgamma Z gamma Non SM! Aachen EPS03
DiBoson(Wg) Aachen EPS03
DiBoson:Wgamma Wg->eneg Wg->mnmg Aachen EPS03
WW DiBoson Df~0 Events compatible with tt dilepton Aachen EPS03
Run II with 2 fb-1 will provide a chance to: • Measure Mw to ±40 MeV/c2 • Measure Mtop to ±3 GeV/c2 DØ / CDF Run 2a Goal Constraints on SM Higgs Mass W Mass(Perspectives for RunII) Aachen EPS03
s.BF(W->lvl) R= s.BF(Z->ll) CDF (e): 9.880.24(stat)0.44(syst) CDF(m):10.690.28(stat)0.31(syst) D(e) :10.340.35(stat)0.39(syst) TeV :10.370.16(stat)0.28(syst) From R Tevatron Combined Measurement… First RunII Tevatron Combined (D0+CDF) Measurement • From Tevatron Combined R: • D (e channel) • CDF (e,m channel) Extract Larger systematic uncertainties dominated: Detector Simulation (CDF e) Background Estimates(CDF/D e) Lepton ID (all channels) Aachen EPS03