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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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Presentation on theme: "Current and Anticipated Results in Bottom and Charm Physics from the Tevatron Jonathan Lewis Fermilab Aspen Winter Conference January 2003."— Presentation transcript:

1 Current and Anticipated Results in Bottom and Charm Physics from the Tevatron Jonathan Lewis Fermilab Aspen Winter Conference January 2003

2 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

3 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

4 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

5 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

6 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

7 R #1 Rate

8 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

9 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

10 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

11 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

12 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

13 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

14 J. Lewis b and c Physics at the Tevatron14 R #2 Recognition (Tagging)

15 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 -

16 J. Lewis b and c Physics at the Tevatron16 Expected Tagging Performance  Both Experiments relying on forward tracking and large lepton coverage

17 R #3 Reconstruction (and results!)

18 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

19 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 -

20 J. Lewis b and c Physics at the Tevatron20 D0 Tracking: Neutral Vees  K S 0 → π + π -  Λ 0 → pπ

21 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 +

22 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

23 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

24 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

25 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  

26 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

27 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

28 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)%

29 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

30 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 %

31 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

32 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

33 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

34 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

35 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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