CDF Winter 2010 Results! Matthew Herndon, University of Wisconsin Madison Fermilab Wine and Cheese Seminar, March 2009
Tevatron and CDF EXCELLENT TRACKING TRIGGERED TO 1.5 GeV/c CAN FIND LEPTONS IN COVERAGE GAPS • Tevatron: 2TeV pp collider • Has now delivered 8fb-1! • CDF properties • Silicon Tracker • |η|<2, 90cm long, rL00 =1.3 - 1.6cm • Drift Chamber(COT) • 96 layers between 44 and 132cm • Muon coverage • |η|<1.5 • Outer chambers: high purity muons • Electron and general Calorimeter • |η|<2.8,3.5 Results in this talk use 2.0fb-1-5.4fb-1
Primary CDF Goals • Original detector and upgrade designed around physics goals • Observe Bs oscillations: SVT (silicon vertex trigger), L00 and TOF • Observation of top (run 1) and single top (run 2): high efficiency lepton detection and the silicon vertex detector • 1% precision top mass measurement: precise/understood calorimeters • Worlds most precise W mass measurement (at the time): COT • Observation of all di-boson processes: large lepton acceptance • Search for new physics: example SUSY tri-leptons, low pt di-lepton triggers • Higgs sensitivity: The whole CDF detector These goals achieved! but more to do
Outline • 1) QCD: quark and gluon physics • Today: Jets, particle production, min bias • 2) B: Heavy hadron physics • Today: Lifetimes, rare decays, Bs Polarization • 6) Higgs • Today SM, MSSM, nMSSM Higgs searches • 3) Top • Today: mtop, width, spin, single top, t’ • 5) Exotics: Direct searches for new physics • Today: di-boson resonances • 4) Electroweak, W, Z, photon, physics • Today Z rapidity, di-boson physics
QCD • QCD Physics: • Interactions of quark and gluons • Measurements of total and differential jet cross sections and properties , proton and aniti-proton PDFs, individual particle production, min-bias, diffraction • The fundamental knowledge necessary for our new physics searches and precision measurements • Today: particle production, min bias, Z+Jets,
Hyperon Production • Differential production of hyperons • Min bias data sample • Λ0pπ, Ξ+Λ0π+, Ω+Λ0K+ • Cross section drops by 7 for each s quark
Particle Multiplicity • Multiplicity of charge hadrons |η| < 1.0, pT > 0.4 GeV • Typically not well modeled and difficult to extrapolate to higher energies. Also needs to include multi-parton interactions • Data sample: Min bias + high multiplicity events • Systematic uncertainty • Correcting data back to MC • Example: High multiplicity trigger
Z + Jets • Differential cross section of Z + jtes • Data sample 2.4fb-1 • Opposite charge muons: 66 < mll <116 GeV • Cone 0.7 midpoint jets ET > 30GeV, |y|<2.1 • Compare to NLO pQCD predictions, MCFM
Jet, Z pT Balancing • Goal: Improve understanding of jet energy measurements • Data sample 4.6fb-1 • Opposite charge electrons or muons: 80 < mll <100 GeV • Single central jet ET > 8GeV • Separation of quark and gluon jets • Track multiplicity • Kinematic properties • Many sources of systematic uncertainty are studied • Large angle FSR and single particle response dominate. Order 2-3% each. Explains observed discrepancy
B Physics • B and Charm Physics: • Physics of heavy hadrons • Masses, lifetimes, widths, branching fractions, rare decays, properties. • Goal: Observe Bs meson oscillations. Accomplished! • New Goal: CPV in the Bs, indirect searches for new physics • Today: Lifetimes, BX rare decays, Bs Polarization
B Hadron Lifetimes • B hardron lifetimes: B+ J/ψK+, B0 J/ψK0*, Λb ΛJ/ • Worlds most precise lifetime determinations Substantially improved lifetime resolution understanding τ(B+)/τ(B0) = 1.088 ± 0.009stat ± 0.004sys τ(Λb)/τ(B0) = 1.020 ± 0.030stat ± 0.008sys Λb: 1.537 ± 0.045stat ± 0.014sys ps
BμμXs • Rare decays B μμXs: B+ μμK+, B0 μμK0*, Bs μμ • Decay to strange mesons and non resonant muons • FCNC process. NP could modify rate or decay distributions • Observation of Bs μμ! Measurement of AFB(muons) and FL(K0*) BR(Bs) = (1.44 ± 0.33stat ± 0.46sys)x10-6 Competitive with B factories
Bs Polarization B factory charmonium vs. s penguin decays: ccs vs css. Discrepancy observed in sin2 and polarization Equivalent Bs test is: BsJ/(css) vs. Bs (sss) First step is a polarization analysis. CPV analysis? Expected higher fL, Possibility for new physics open
Top • Top Physics: • Exploit the run 2 top sample to measure all of the properties of the heaviest quark. • Cross section, mass, width, branching fractions, charge… • Goals: 1% σ(m_t), accomplished! • σ(σtt) < 10%, 6.4% achieved! • Observe single top, accomplished! • New Goal: 1GeV σm,top • Today: Mass and width, s vs. t channel single top production, spin correlations, t’ search
Top mass • Template based top mass measurement • Lepton+Jets and Dilepton chanel with 4.8fb-1 • Likelihood fit over variables sensitive to top mass • Simultaneous constraint of jet energy scale using W in lepton+Jets • Uncertainties • Jet energy scale • MC modelling for templates • More precise than CDF winter 2009 combination! • 172.6 ± 0.9stat+JES ± 1.2sys mt =171.9 ± 1.1stat+JES ± 0.9sys GeV
Top mass • Matrix element based top mass measurement • Lepton+Jets with 4.8fb-1 • NN for background discrimination and jet energy scale constraint • Also more precise than CDF 2009! • Expect 1GeV precision achievable mt =172.8 ± 1.3total GeV 0.7stat,0.6JES, 0.8sys
Top Width • Template based top width measurement • Lepton+Jets with 4.3fb-1 • Simultaneous constraint of jet energy scale using W jets • Upper limit placed on top width 95% CL: Γtop < 7.5 GeV 68% CL: 0.4 GeV < Γ top < 4.4 GeV
Top Spin • Top spin correlation with 4.3 fb-1 • Top decays weakly before hadronization. Spin conserved in top decay. • Test correlation between top and anti-top • Could be modified by new physics • Measure opposite spin fraction, f0, and spin correlation coefficient, κ. Uses helicity angels of lepton, d, and b quarks f0 = 0.80 ± 0.25stat ± 0.08systκ = 0.60 ± 0.50stat ± 0.16 sys (3σ possible with D0)
Single Top • Single top observed. 3.2fb-1 σST= 2.3+0.6 pb, 5.9σ significance • Separately measure s and t channel production. • Measurement driven by statistics of single and double tag events -0.5 σt = 0.8 ± 0.4 pb σs = 1.8 ± 0.7 pb -0.5
t’ Search • Search for heavy top t’ Wq • Leptons + Jets events with 4.6 fb-1 • Reconstruct mass of t’ and search in HT and mt’ • May occur in little Higgs, forth generation, …
Electroweak • Electroweak physics: • Study of the massive gauge bosons and the photon. • EW boson total and differential cross section. Di-bosons • Goal: Observe all di-boson processes, accomplished! • σm,W 48 MeV • New goal: exceed LEP σm,W • 30x statistics availalable • Today: Z rapidity and di-bosons.
Z Rapidity • HERA F2 / jet & Tevatron jet & W/Z data necessary for accurate PDFs for robust LHC predictions • Z rapidity in 2.1 fb-1 using Z ee σ(y>0) = 256.4 ± 1.0stat σ(y<0) = 256.9 ± 0.9stat σ = 256.6 ± 0.7stat ± 2.0sys
Dibosons • Physics interests: observe fundamental EW processes • Anomalous BSM couplings could modify total or differential σ • Lepton + Jets di-boson modes a milestone on the way to Higgs • ZZ seen in 4 lepton at 5.7σ • All now observed!
Di-bosons • WW/WZ lepton + Jets observations • Using mjj and matrix element techniques with 4.3-4.6fb-1 5.4 σ 5.2 σ σ = 18.1 ± 3.3stat ± 2.5sys SM = 15.1 ± 0.9 pb σ = 16.5 +3.3-3.0 ± 3.5sys
Di-bosons • Zγ with 5.1 fb-1 • Direct coupling would be anomalous • SM contribution from ISR and FSR Limits (@ 1.2 TeV) : |h3| < 0.037, |h4| < 0.0017 Already significantly better than LEP & will improve (~ factor 2) with Z -> ννγ
Exotics • Exotics Physics: • Direct searchs for fundamental new particles. • Goal: Discover new physics • Today: • massive di-boson resonances. • MSSM Higgs searches including new Tevatron combination • nMSSM Higgs search ? ? ? ? ?
Exotic Di-bosons • Search for massive resonances in WW/WZ • Dataset: electron + MET + Jets with 2.9 fb-1 • Full invariant mass reconstruction with weights for 2 possible solutions • Limits placed on R/S gravitons, W’, Z’ 0.1
MSSM Higgs: bb • 3b channel: bbbb. • Di-b-jet background too large in bb channel • Search for peak in di-b-jet mass distribution of leading jets in 3b sample • Key issue: understanding the quark content of the 3 jets • Secondary vertex tagger. • Use vertex mass combinations, m1+m2 and m3 • No significant evidence for Higgs: • Limits tan vs mA • 3b search very sensitive with certain SUSY parameter choices • Next step is to include this in the combination
MSSM Higgs: • CDF and DØ channels • pure enough for direct production search • MSSM limits not highly parameter dependent • Will include in future: bb, bb • Key issue: understanding Id efficiency • Large calibration samples: W for Id optimization and Z for confirmation of Id efficiency • No Evidence for SUSY Higgs • Limits: tan vs mA • generally sensitive at high tan
nMSSM Higgs in Top Decay A CP odd Higgs not excluded below 2mb
Higgs • Higgs Discovery group • Direct searches for SM or BSM Higgs bosons • Goal: Achieve sensitivity to exclude or find evidence for the SM Higgs boson • Today. SM Higgs searches including new high mass result
SM Higgs: VHqqbb • VH qqbb – All jet mode! 4.0 fb-1 • Backgrounds: QCD multijet events • Key issue: develop accurate method to predict b-tagged background. • Discriminant. NN based, includes jet shape information Factor of two improvement over previous result! Results at mH = 115 GeV: 95%CL Limits/SM
SM Higgs: Hγγ • Hγγ with 5.4 fb-1 • Excellent di-photon mass resolution makes resonances detectable • First dedicated SM Hγγ search Results at mH = 120 GeV: 95%CL Limits/SM Flat sensitivity will help in mH=120-140GeV region
SM Higgs: WHlbb • WHlbb - signature: high pT lepton, MET and b jets • Backgrounds: W+bb, W+qq(mistagged), single top, Non W(QCD) • Key issue: estimating W+bb background • Shape from MC with normalization from data control regions • Matrix element analysis with extended muon acceptance, 3 jet events Results at mH = 115GeV: 95%CL Limits/SM Worlds most sensitive low mass Higgs search
SM Higgs: HWW W+ H μ+ W+ W- ν e- W- • HWWll - signature: Two high pT leptons and MET • Primary backgrounds: WW and top in di-lepton decay channel • Key issue: Maximizing signal acceptance • Excellent physics based discriminants Spin correlation: Charged leptons go in the same direction ν
Tevatron Higgs Combination Exp. 0.92, 0.87, 1.04 @ 160,165,170GeV Published: Accepted in less than 1 week! PRL cover Editors suggestion Special viewpoint article written Obs. 0.93 @ 165 GeV SM Higgs Excluded: mH = 163-166 GeV
New High Mass Contributions Results at mH = 165 GeV: 95%CL Limits/SM • VH VWW lll +MET • WH and ZH search (in combination). Also ZH search in 2 jets only • H WW lτ + MET, hadronic tau (in combination)
New CDF HWW Result Approaching SM sensitivity! 36 Higgs Events!
New CDF HWW Result Exp. 1.07 @ 160 GeV, 1.02 @ 165 GeV Obs. 1.05 @ 160 GeV, 1.11 @ 165 GeV
Conclusions CDF physics program is strong! Many of the primary goals of the CDF physics program have been achieved With larger datasets and innovation more impressive goals are achievable The centerpiece of the CDF physics program, sensitivity to the Higgs boson (limits or evidence), will be achieved soon!