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Current and Anticipated Results in Bottom and Charm Physics from the Tevatron Jonathan Lewis Fermilab Aspen Winter Conference January 2003
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J. Lewis b and c Physics at the Tevatron2 B Program: Complement to e + e - Factories B s Flavor oscillations CP Violation Fits combining B s →h + h - and B d →h + h - New physics in B s 0 → J/ψ φ Mass, lifetime B c Mass, lifetime, production, resonances(?) b Baryons: Λ b, Ξ b Mass, lifetime CP Violation Λ b → pπ - vs. Λ b → pπ + B and D rare decays No tagging penalty! QCD B and D production in pp collisions Quarkonium Today’s Talk: Where we are on road to the Physics Results from Summer 2002
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J. Lewis b and c Physics at the Tevatron3 Run 1: The Foundation B triggers required leptons in the final state trigger Semileptonic channel highlights: B 0 B 0 Mixing, Production, Lifetimes m = 0.47 ± 0.07 ps -1
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J. Lewis b and c Physics at the Tevatron4 Run 1: b J Rich and pure channel Highlights: Lifetimes, production, B c, first hint of CP B 0 J K S 0 CDF Run 1 Yesterday’s sensation is today’s calibration
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J. Lewis b and c Physics at the Tevatron5 Run 2 Revolution Higher Energy Higher Luminosity Higher Bandwidth Precision Tracking CDF: New 96-layer drift chamber, 7-layer silicon barrel D0: 2T solenoidal field, 8-layer fiber tracker, silicon barrel and forward disks CDF: Time-of-flight detector for Kaon ID Displaced Track Triggers for all-hadronic channels What was offline analysis has moved to Level 2 trigger
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J. Lewis b and c Physics at the Tevatron6 B Physics for Dummies: The 3 R’s Rate Cross section Luminosity Trigger Recognition Tagging Reconstruction Extract the signal Minimize the background
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R #1 Rate
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J. Lewis b and c Physics at the Tevatron8 Cross Section B physics enabled by large cross section b)~10 b for p T >5 GeV, |η|<1 ~1000 B per second at design luminosity Compare to ~10 B per second at Υ (4S) factories Run 1 total cross section factor ~2 above NLO predictions s=1800 GeV Effect seen over many channels Energy dependence (630 vs. 1800 GeV) agrees with QCD
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J. Lewis b and c Physics at the Tevatron9 Theoretical Improvements Recent work on the non-perturbative physics Fragmentation functions from NRQCD-inspired fits to LEP data (names) Resummation of next-to-leading logs and retuning of Petersen fragmentation ( =0.002) Looking forward to marriage of matrix-element and parton-shower Monte Carlos Kniehl, Kramer hep-ph/9901348Cacciari, Nason hep-ph/0204025
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J. Lewis b and c Physics at the Tevatron10 Cross Section: Run 2 First D0 measurement Muon + Jet s=1960 GeV b content from P T,rel Lepton momentum perpendicular to jet direction Expectations for Run 2 Precision tests of perturbative region (p T 2 »m b 2 ) with large data samples Detailed exploration of non-perturbative region d /dp T (b J ) down to p T (b)=0 Data PYTHIA
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J. Lewis b and c Physics at the Tevatron11 Luminosity Tevatron performance thus far below expectations Getting better Record luminosity: 3.6×10 31 cm -2 s -1 Best week: 7pb -1 CDF: 80 pb -1 good runs Excludes studies, commissioning 65 pb -1 with silicon Typical efficiency for December ~80% Start of CDF physics data
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J. Lewis b and c Physics at the Tevatron12 Trigger Electrons: E T,P T >2 GeV Muons: P T >1.5 GeV Tracks: P T >1.5 GeV Displaced tracks Typically require d 0 >100 m, P T >2 GeV CDF SVT resolution ~50 m Includes 30 m rms beam width Differences: CDF pipelined Level 1 allows hadronic B decay trigger D0 has | |<2 low-p T lepton coverage
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J. Lewis b and c Physics at the Tevatron13 Hadronic Trigger Nominal cuts p T > 2 GeV p T1 +p T2 >5.5 GeV Opposite Charge Opening Angle 2º< <90º for b c 20º< <135º for d 0 >100 m Loose cuts (b c only) p T > 2 GeV 2º< <90º d 0 >100 m Automatically updating prescale
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J. Lewis b and c Physics at the Tevatron14 R #2 Recognition (Tagging)
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J. Lewis b and c Physics at the Tevatron15 What’s new (and old) Tagging plans follow from CDF Run 1 results Leptons and jet-charge with greater coverage Same-side tag New Element: Time-of-flight for CDF ID Kaons for P T < 1.6 GeV 120 ps resolution φ →K + K -
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J. Lewis b and c Physics at the Tevatron16 Expected Tagging Performance Both Experiments relying on forward tracking and large lepton coverage
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R #3 Reconstruction (and results!)
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J. Lewis b and c Physics at the Tevatron18 Physics Goals With Two Leptons CPV in B 0 → J/ψ K S 0 Yesterday’s sensation is today’s calibration Anomalous CPV in B s 0 → J/ψ φ B 0 →μμK ( Λ b →J/ψ Λ: Lifetime, production, CPV, etc. B c → J/ψ π, J/ψ ℓν Quarkonium production
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J. Lewis b and c Physics at the Tevatron19 D0 on the Road to Physics M = 3.08 0.04 GeV = 0.78 0.08 GeV Muon stand alone system Muon plus central tracking Good Resolution from new tracker J/ψ → μ + μ -
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J. Lewis b and c Physics at the Tevatron20 D0 Tracking: Neutral Vees K S 0 → π + π - Λ 0 → pπ
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J. Lewis b and c Physics at the Tevatron21 D0: First Exclusive B Decays ~5pb -1 Sample of 3000 J/ψ Outer muon trigger p T (μ) > 2 GeV p T (K) > 0.5 GeV p T (B) > 10 GeV Vertex fit χ 2 >10 L xy >120 μm B + → J/ψ K +
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J. Lewis b and c Physics at the Tevatron22 D0: First Physics Inclusive b → J/ψX Lifetime 416 ± 30 signal events 2184 ± 47 prompt J/ ’s (B) = 492 ± 37 m (stat. error only) Compare to PDG: (B) = 469 m J/ψ Cross Section 5pb -1 Large rapidity coverage
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J. Lewis b and c Physics at the Tevatron23 CDF Results: B Meson Masses 18 pb -1, incomplete silicon coverage B s uncertainties already close to Run 1 Systematics will be greatly reduced with more data and recent track reconstruction improvements B + → J/ψ K + 5280.6 ±1.7 ±1.1 B 0 → J/ψ K 0 5279.8 ±1.9 ±1.4 B s 0 → J/ψ Φ 5360.3 ±3.8 ± 2.9 2.1
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J. Lewis b and c Physics at the Tevatron24 CDF Results: B + → J/ψ K + Lifetime 18 pb -1 Incomplete Silicon Coverage 154 ± 15 Events τ + = 1.49 ± 0.14 (stat.) ± 0.04 (sys.) Compare Run 1: 1.68 ± 0.07 ± 0.02 PDG: 1.674 ± 0.018 Expectation: Systematics to be greatly reduced with more data
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J. Lewis b and c Physics at the Tevatron25 All Hadronic Modes: b→c Primary goal: B s -B s favor oscillations a.k.a. Mixing Measure frequency Δm s Δm s /Δm d yields |V ts /V td | up to 5% theoretical uncertainty Important constraint on CKM Much more physics along the way and beyond Masses Lifetimes Other CP violation studies
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J. Lewis b and c Physics at the Tevatron26 Before b comes c Hadronic trigger yields large charm samples Both direct and from b decays Significant measurements at hand quickly for charm production and decay properties D + -D s + Mass Splitting Decay mode: φπ, φ →K + K - Δm= 99.28±0.43±0.27 MeV PDG: 99.2±0.5 MeV Systematics dominated by fit model and selections Can be reduced with more data
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J. Lewis b and c Physics at the Tevatron27 D 0 →h + h - Decays Measure Cabibbo- suppressed branching ratios Requires detailed modelling of detector performance No particle ID Account for both hypotheses for K π mode 10 pb -1 sample Systematics dominated by background and acceptance models K-π+K-π+ π+π-π+π- K+K-K+K- K-π+π0K-π+π0
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J. Lewis b and c Physics at the Tevatron28 Branching Ratio Results Γ(D→KK)/ Γ(D→Kπ) = (11.17±0.48±0.98)% PDG: (10.83±0.27)% Γ(D→ ππ)/ Γ(D→ Kπ) = (3.37±0.20±0.16)% PDG: (3.76±0.17)%
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J. Lewis b and c Physics at the Tevatron29 Charm Production Displaced track trigger sensitive to long lived D mesons Prompt production much greater than from B Can differentiate based on lifetime and impact parameter (d 0 ) Efficiency sculpted by trigger cuts Significant impact parameter Prompt D Long apparent lifetime D from B Excluded OK
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J. Lewis b and c Physics at the Tevatron30 Prompt Charm Fraction Prompt fraction from d0 distribution Resolution function from simulation Check in K S → ππ sample B fraction in several D meson channels D 0 K 16-24 % D* D 0 11-20 % D K 11-17 % D s 32-40 %
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J. Lewis b and c Physics at the Tevatron31 Charmless B Decays Extract CP violation from multiple modes B d →ππ B d →Kπ B s →Kπ B s →KK Separate Penguin and Tree amplitudes First signal b u d d ub d d d d u u g 3:1 Signal-to-noise Rates understood Consistent with expectations after correction for acceptance
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J. Lewis b and c Physics at the Tevatron32 Sensitivity for γ Separate modes on a statistical basis using mass shapes and dE/dx Sensitivity depends on strong-interaction phase between tree and penguin processes For 2 fb -1 expect δγ~5-10° B d →ππ B d →Kπ B s →Kπ B s →KK
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J. Lewis b and c Physics at the Tevatron33 First All-Hadronic Decays B - →D 0 π -, D 0 →K - π + 5000 20000 15000 10000 0 Excluded B s Mixing S:N 1:2 1:1 2:1 Mixing 5σ Discovery Sensitivity Event Yield 56±12 Events
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J. Lewis b and c Physics at the Tevatron34 Outlook CDF 4 out-of 5 majority logic for SVT tested this month Expect ~50% efficiency improvement Hoping to run DAQ at higher rates and increase cross section of B events to tape Level 1: 12 kHz → 25 kHz D0 Track trigger commissioning complete this winter Fiber and silicon Hoping to improve trigger bandwidth Level 1: now 1 kHz, want 4 kHz Tevatron 100 pb -1 more by summer
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J. Lewis b and c Physics at the Tevatron35 Conclusions CDF and D0 detectors and reconstruction performing well First B signals seen Lots of work to do Exciting results just around the corner
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