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B P hysics at CDF R esults and P rospects

B P hysics at CDF R esults and P rospects. Lake Louise Winter Institute Lake Louise, Canada - 15 th -22 nd February 2003. Iván Vila Instituto de Física de Cantabria, Spain. In this talk. Introduction Cross-section Masses Lifetimes Spectroscopy Rare Decays CP Violation

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B P hysics at CDF R esults and P rospects

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  1. BPhysics at CDFResults and Prospects Lake Louise Winter Institute Lake Louise, Canada - 15th -22nd February 2003 Iván Vila Instituto de Física de Cantabria, Spain

  2. In this talk • Introduction • Cross-section • Masses • Lifetimes • Spectroscopy • Rare Decays • CP Violation • Bs Mixing DISCLAIMER:1001 B and Charm physics analysis at CDF Here not at all exhaustive summary I. Vila Lake Louise Winter Institute 2004

  3. B physics at Tevatron • Large b production cross-section • s(bb) ~ 50mb (5kHz @ E32) • s(bX, |y(b)|≤1) ~ 30mb (3000Hz @ E32) • compare: s(bb) ~ 1nb at U(4S) ( 10Hz @ E34) • Many B hadrons states produced: • B0, B+, Bs, Lb, Bc, b • But… HUGE inelastic cross section ~ 100mb • A dedicated selective trigger needed vs. B factories inclusive trigger. I. Vila Lake Louise Winter Institute 2004

  4. ~ 1 mm b, c decays primary vertex secondary vertex impact parameter B Triggers • Di-lepton - dilepton sample • pT(/e)>1.5/4.0 GeV/c • J/ modes, masses, lifetime, x-section • Yield 2x Run I (low Pt threshold, increased acceptance) • lepton + displaced track - semileptonic sample • pT(e/)>4 GeV/c 120 m<d0(Trk)<1mm, pT(Trk)>2 GeV/c • Semileptonic decays, Lifetimes, flavor tagging. • B Yields 3x Run I • Two displaced vertex tracks - hadronic sample • pT(Trk)>2 GeV/c, 120 m<d0(Trk)<1mm, S pT>5.5 GeV/c • Branching ratios, Bs mixing, … • Hadronic mode sensitivity increased about five orders of magnitude ! I. Vila Lake Louise Winter Institute 2004

  5. B production – Cross Section • RunI b cross-section ~ 3x NLO QCD • theoretical approaches: new physics, Next-to-Leading-log resummations, non perturbative fragmentation function from LEP, new factorization schemes… • Only top 10% in Pt of the total x-section measured • New measurements to lower pT(B) : • Inclusive J/Psi cross section up to PT(J/Psi)=0 (first time hadron collider) • Bottom Quark Production cross-section I. Vila Lake Louise Winter Institute 2004

  6. B Lifetimes and Masses • Inclusive measurements (J/ X dimuon sample) • Still statistical limited ~ 138 pb-1 • Test of HQET predictions • First measurement of lb using a exclusive reconstruc. • Lifetime measurements using the inclusive semileptonic sample are still under progress (expect results soon) • Mass fit using fully reconstructed B  J/ X decays • B0, B+ competitive with PDG, and Bs and lb the World’s best measurement I. Vila Lake Louise Winter Institute 2004

  7. Spectroscopy–Exotic States X(3872) • New narrow state observed first by Belle in decay modes • Charmonium state not expected near mass peak. • D* Dbar deuteron-like molecule ? • CDF confirms X in 220pb-1 • Preference for M( ) > 500MeV • 670±90 candidates, sign.~ 12s • Mass scale using y(2S) peak I. Vila Lake Louise Winter Institute 2004

  8. Rare decays - Bs,Bd mm • BR(Bs  mm) ~ 10-9 in SM (SUSY physics two orders of magnitude enhancement) • Blind analysis optimized for 300-400 pb-1 (~ 1  0.3 expected bkg) Limits at 90% C.L. BR(Bs->MuMu) < 5.8 E-7 BR(Bd->MuMu) < 1.5 E-7 • Bs factor 3 better than best published limit (Run I) • Bd slightly better than Belle’s at LP03: 1.6 E-7@90%CL • Still room for improvement:  Acceptance &  bkgs I. Vila Lake Louise Winter Institute 2004

  9. CPV - Two body charmless decays B  h+h- • Time dependent asymmetry Bd  pp (a angle) and Bs  KK (g angle) • Direct CP asymmetry of the self tagging modes Bd  pK and Bs  Kp 1. extracting the signal 2. Separation of the components • dE/dx ~ 1.3s for K/p separation • Statistical separation is still possible • Unbinned log-likelihood fit defined including • Kinematical variables M(pp) and a=(1-p1/p2)q1 • dE/dx Online hadronic selection + B pointing prim. vertex, displaced & isolated I. Vila Lake Louise Winter Institute 2004

  10. CPV - Direct ACP Selftagging Modes - Projections • First observation Bs KK • Direct ACP violation ~ 0 I. Vila Lake Louise Winter Institute 2004

  11. Bs mixing – Signal Reconstruction • Bs mixing unique to CDF requires • Event yield • Clean signals (S/B) • Vertexing resolution • Tagging effectiveness: eD2 • For semileptonic decays • Fully reconstructed decays boost resolution • CDF Golden Channel Bs Dsp I. Vila Lake Louise Winter Institute 2004

  12. Bs Mixing - Flavor tagging • Flavor taggers optimized on high statistics semileptonic sample • Unbiased performance in high purity inclusive sample CDF Results: Same-side (B+)D2(2.10.7)% Muon tagging D2 (0.70.1)% JQT, SET almost there OSKT NEW! RunII on progress I. Vila Lake Louise Winter Institute 2004

  13. Bs Mixing – Improvements • Idealistic “Yellow Book” projections • Detector acceptance and trigger efficiency very improved 2x Bs selection • Under current conditions (BsDsp ) • S = 1600 events/fb-1 • S/B = 2/1 • eD2 = 4 % (SLT+SST+JQT) • st=67 fs • Modest improvements • Adding Ds  K*K,KsK y Bs  Ds3p S = 1600 events/fb-1  2000 events/fb-1 • L00 innermost silicon layer, event by event beam-line reconstruction • eD2 = 5 % st=67 fs  st=50 fs I. Vila Lake Louise Winter Institute 2004

  14. Bs Mixing – Projections • Short term 500 pb-1 (no improvement up to 2005) • 2s (for Dms = 15 ps-1) • Reach the current indirect limit. • Cover the Standard Model favored range • Beyond the SM favored range (conservative improvements up to 2008): • 5 s if Dms = 18 ps-1 with 1.8 fb-1 • 5 s if Dm = 24 ps-1 with 3.2 fb-1 I. Vila Lake Louise Winter Institute 2004

  15. Summary and Conclusions • After 2003 fall shutdown the Tevatron is performing very well. • CDF Run II accumulated over 290pb-1 of data (~ 2.5 larger than Run I). • The new displaced track trigger has been a great success • CDF is back in the game of producing world class results. • (Unique Bs,Lb physics, competitive Bd, Bu physics in same cases) • Benchmark lifetime and mass analysis probe excellent detector performance • World best limits Bs and Bd mm • First observation of Bs  KK modes • CPV in B  hh, CDF major player in this arena. • Bs mixing: • Reach current indirect limit with 500pb-1 (end 2004) • 5s sensitivity over SM preferred range (up to 24 ps-1) in 3fb-1(end 2008) I. Vila Lake Louise Winter Institute 2004

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