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Experimental Status of Flavor Physics: Snapshot From CKM2005 (March 05)

Experimental Status of Flavor Physics: Snapshot From CKM2005 (March 05). Vivek Sharma University of California, San Diego. Special Thanks : Andreas Hocker, Kevin Pitts, Ben Grinstein, Zoltan Ligeti, Bob Kowelewski, and Daniele del Re. What This Talk Won’t Cover.

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Experimental Status of Flavor Physics: Snapshot From CKM2005 (March 05)

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  1. Experimental Status of Flavor Physics:Snapshot From CKM2005 (March 05) Vivek Sharma University of California, San Diego Special Thanks : Andreas Hocker, Kevin Pitts, Ben Grinstein, Zoltan Ligeti, Bob Kowelewski, and Daniele del Re

  2. What This Talk Won’t Cover • Flavor physics is a vast subject with many subtleties • For a snapshot of this field, see the presentations, discussion and roundtable during CKM2005 workshop(s) at UCSD in March 2005 • http://ckm2005.ucsd.edu/ • In this review I will not cover • Light quark results (Focus of this workshop) • Impressive strides made in (Heavy) flavor theory • “Grade” the “utility” of Lattice results on HF Parameters • http://ckm2005.ucsd.edu/agenda/wed1/bernard.pdf • Important experimental tests of theory of flavors • Discussion of future (super) facilities

  3. Semileptonic B Decays Outline of This Talk Measurements related to Overconstraining the “db’ Unitarity triangle • Facilities for Heavy Flavor Studies : status • Measurements of sides of the Unitarity Triangle • Vcb • Vub • Vtd & Vts : Electroweak penguin and BS Mixing • CP Violation in B Decays and measurements of CKM angles • Direct CPV in B Decays • Gold plated measurement of  with B J/ K0 • Penguin Nuisance in measurement of  = -- • Quest for the angle  in B  DK Direct CPV • Profile of the Unitarity Triangle Circa CKM2005 • Penguin Lust : CP Asymmetries in s-Penguin B Decays and searches for new physics

  4. The Cabibbo Kobayashi Maskawa Matrix VCKM • In the SM, the CKM matrix elements Vij describe the electroweak coupling strength of the W to quarks • CKM mechanism introduces quark flavor mixing • Complex phases in Vij are the origin of SM CP violation • In the Wolfenstein parametrization Mixes the left-handed charge –1/3 quark mass eigenstates d,s,b to give the weak eigenstates d’,s,b’. = 0.226 ± 0.002 A= 0.85 ± 0.05 É= 0.22 ± 0.09 ¿= 0.33 ± 0.05 Experimental goal is precise measurements of magnitudes and phases

  5. Triangles, Triangles, Triangles

  6. Triangles, Triangles, Triangles

  7. Angles of Unitarity Triangle Unitarity Triangles: The “db” triangle For Bu/d System

  8. Facilities for Heavy Flavor Physics BaBar@ PEP-II Belle @ KEK-b CLEO-c @ CESR D0 & CDF @ TeVatron

  9. Era of The Factories: Unprecedented Luminosities ! y’ CLEO-c Ldt>60pb-1 y(3770) Beam Energy (GeV) Ldt >450 fb-1 BELLE Ldt >250 fb-1 CDF & D0 Ldt >800pb-1 Ebeam

  10. Cleo-C Detector Taking Data at e+e-(3770)DD  K- K+ - e+ Complete Survey of Charm Meson Decays • Absolute Charm Branching fractions • Charm decay constants fD • Rates and FF in Semileptonic decays • Strong phases in hadronic D decays critical for CPV measurement in B decays • DD Mixing and CP violation See D. Asner’s talk on Cleo-c results and prospects

  11. CDF& D0 Equipped with Silicon Inner Tracking Intermediate Silicon Layers of CDF CDF D0

  12. Heavy Flavor Physics at CDF& D0 • Silicon gives the “lifetime optic” to CDF & D0, enables lifetime based analyses and trigger…..now proven to work ! • All species of heavy mesons and baryons are produced • Goals • Map out weak decay of all b hadrons, including b and Bc • Exploration of the Bs meson system • Width difference  • Bs Oscillations (take over from LEP/SLD) • CPV studies (Bs mixing and luminosity willing) • Searches for rare decays enhanced by NP • B + - • Electoweak penguin etc

  13. e+  e- Belle and Babar: Dominating B Physics Since ‘99 Excellent Tracking, PID Enough energy to barely produce 2 B mesons, nothing else! B mesons are entangled  Need for Asymm energy collisions

  14. Radiative Penguin Decays: Window to NP b s l+l b sg See Hitoshi Yamamoto’s talk for Details

  15. FCNC Via Electroweak Loops & New Physics ? ? ? Experimentally probed via measurements of decay Rate and Asymmetry

  16. Measurement of Inclusive b s Decay Rate Belle ? Eg > 1.8 GeV Data agrees with SM (10%) BaBar sum of exclusive BaBar Inclusive, Eg > 1.9 GeV CLEO Inclusive, Eg > 2.0 GeV Belle Inclusive, Eg > 1.8 GeV SM Theory uncertainty could improve to ~5% (NNLO) ?? Experimental precision will keep pace (500 fb-1)

  17. BaBar Belle Rate of b d • Decay CKM-suppressed (|Vtd /Vts| ) w.r.t. b s; sensitive to |Vtd| • Inclusive b d measurements background challenged ! • b s   20 background ! Needs K+,KS and KL veto • Exclusive processes are current exptal target:B  () • Theor. estimate imprecise B(B  () )  [0.5-2.0]10-6 : Ali, Buchalla etal • Ratio R(/K*)reduces theory error, estimates |Vtd /Vts| “ At the verge of observation, Central Values in SM range”

  18. Constraint On |Vtd /Vts| Compete with Bs Mixing

  19. Inclusive Rate Of b s l+l

  20. Forward–backward asymmetry(AFB) B backward forward    Lepton pair CM AFB  AFBunder CP: Sensitive to New Physics through Non-SM CPV phases FB Asymmetry in b sl+l As Future Probe of New Physics Ali et al. PRD 66,034002(2002) scenarios consistent with measured rate NP AFB sensitive to relative signs of Wilson coefficients : measurably large BaBar  ACP=0.22  0.26(stat)  0.02(syst) Consistent with SM theory but Data limited Potential to rule out some NP scenarios (where AFB is of opposite sign w.r.t SM) with  500 fb-1

  21.   First Investigations of Bs Oscillations at Tevatron (Following LEP &SLD Searches)

  22. LEP-SLD Limit On Bs Oscillation Using inclusive Bs Samples Amplitude scan Method • Fit Mixing Prob  D*A*cos(Dm t) at fixed Dm • Expect A=1 for real Dm, 0 otherwise • Sensitivity: Dm such that 1.645sA =1 • 95% CL: Dm such that A+1.645sA = 1

  23. Critical Requirements for Bs Oscillation Measurement

  24. Ds+D++ This is the future Bs Samples at Tevatron 5153 signal 900 Bs Ds  with impact parameter trigger

  25. Tevatron Limits On Bs Oscillation World limit (LEP/SLD) unchanged CDF Good first attempt to get in the game (Bs mixing is difficult!!) But must improve not just in dataset but also tagging and propertime resolution • m > 7.9ps-1 @95% CL Sensitivity : m =8.4ps-1

  26.   Measurement of |Vcb| & |Vub| from Inclusive Semileptonic B Meson Decays See Hitoshi Yamamoto’s talk for Details

  27. Inclusive Semileptonic Decays: The Big Picture Inclusive El spectrum Rate Shape |Vxb|2 El[GeV] Inclusive Mx spectrum Shape (log-scale) Rate for Mx<1.55

  28. Partial branching fraction experimental observables Lepton energymoments Hadron massmoments Inclusive Approach Using OPE • Intimate knowledge of QCD is required to go from partonic process to the hadronic states • Given mb >> QCD , OPE used to describe inclusive rates in terms of |Vcb|, mb and a few nonperturbative matrix elements that enter at the order of (QCD/mb)2 and higher orders • One extracts these parameters from a global fit to • Inclusive rate, lepton energy (Eℓ) & hadron mass (mX) moments • Integrations are done for Eℓ > Ecut, with Ecut varied in 0.6–1.5 GeV

  29. Fit Parameters in OPE Expansion BABAR PRL 93:011803 • Calculation by Gambino & Uraltsev (hep-ph/0401063 & 0403166) • Kinetic mass scheme to • Eℓ moments • mX moments • 8 fit parameters • 8 moments available with several Ecut • Sufficient degrees of freedom to determineall parameters without external inputs • Fit quality tells us how well OPE works kinetic chromomagnetic spin-orbit Darwin

  30. Example OPE Fit To BaBar Semileptonic Spectra BABAR PRL 93:011803 ● = used, ○ = unusedin the nominal fit mX moments BABAR c2/ndf = 20/15 Eℓmoments Red line: OPE fitYellow band: theory errors Remarkable agreement between data and theory !

  31. OPE Fits to BaBar Inclusive SL Data PRL 93:011803 • and consistent with B-B* mass splitting and QCD sum rules • and the scale of consistent with theoretical expectations • Remarkable agreement between data and theory Uncalculatedcorrections to G kinetic mass scheme with m = 1 GeV

  32. |Vub| From Inclusive bu l Spectrum • |Vub| can be measured from • The problem: b → cℓv decay Must suppress 50× larger background e.g. using kinematic differences (mu << mc) or particle identification (D*, Kaon content) No perfect observable, All must deal with theory imprecision

  33. Belle 1st and 2nd moment of SF determined Vub From Inclusive Measurements • Experimental requirements in bul signal extraction severely “chops” and reduces the phase space in SL decay • OPE does not provide predictions of differential rates: poor convergence in regions where bcl decays are kinematically forbidden • Non-perturbative shape functions (SF) needed to calculate the extrapolate to full bul spectrum (rate) • Theoretically, only rough features (mean, rms) of the shape functions are known but detailed shape not constrained Use correspondence between Photon spectrum in bs and Lepton energy spectrum in bul Limited by experimental imprecion in Knowledge of the full photon spectrum

  34. BABAR excl(untagged) |Vub| From Inclusive b ul Observables Snapshot of measurements (’04) Example: BaBar Results at CKM2005 Bottomline: Vub measurements approaching 10% precision See Hitoshi Yamamoto’s Talk For Details & BaBar+Belle Averages

  35.   CP Violation in B DecaysMeasurements of Angles of UT Triangle

  36. Loop diagrams from New Physics (e.g. SUSY) can modify SM asymmetry • Clean B mode with “large” rate : • CP Asymmetry measurement is a « Counting Experiment » Observation of Direct CPV in B0K- + T P

  37. BaBar & Belle : Observation of Direct CPV in B Decay Belle BABAR Signal=213953 AK = -0.101  0.025  0.005 Combined BaBar & Belle significance = 5.7 Establishes CPV not just due to phase of B Mixing (M12) Theoretical (npQCD) uncertainties insufficient to prove or rule out NP

  38. B0 B0 fcp fcp B0 B0 B0 B0 fcp fcp 2 2  + + CPV In Interference Between Mixing and Decay CP asymm. can be very large and “cleanly” related to CKM angles Requires time dependent measurement of CP Asymm.

  39. Cartoon of (4S)B0B0 Evolution & Decay

  40. Amplitude ratio Phase of mixing Time-dependent CP Asymmetry Due to Interference in Mixing and Decay (for single weak decay amplitude)

  41. CPV In Interference Between Mixing and Decay: B0 J/K0 CP = -1 (+1) for J/y K0S(L)

  42. B Charmonium Data Samples MES [GeV] MES [GeV] BABAR J/ψ KL signal J/ψ X background Non-J/ψ background (ηCP = +1) ΔE [MeV]

  43. (cc) KSmodes (CP = -1) Sin(2b) Result From B Charmonium K0 Modes J/ψKLmode (CP = +1) background hep-ex/0408127 sin2β = 0.722  0.040 (stat)  0.023 (syst) (PRL 89, 201802 (2002): sin(2β) = 0.741 ± 0.067 ± 0.034)

  44. Sin(2b) Result From B Charmonium K0 Modes Belle sin2β = 0.728  0.056 (stat)  0.023 (syst) WA: sin2β = 0.726  0.037 (5% Measurement)

  45. Measurement of Angle : Dodging Penguins ! [ =-(+) ]

  46. CPV in b u u d Process : B0+- Neglecting Penguin diagram

  47. Tree Penguin Reality in B0+-, + - • Ratio of amplitudes |P/T| and • strong phase difference  • can not be reliably calculated! If no penguins  Spp ~ -0.34 Gronau& London: Estimate dapeng = eff -using isospin relations

  48. Estimating Penguin Pollution in B0+-, + - Similarly for B  system

  49. Rates and Asymmetries in B0 0, B+ - Weak constraint on  [67o -131o] with current statistics

  50. B0+ - System As Probe of  Has Nature’s “Blessing” Blessing # 1 Likelihood projection Although 2 0’s make efficiency small

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