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CP Violation in B Decays and the CKM Matrix

CP Violation in B Decays and the CKM Matrix. Emmanuel Olaiya Rutherford Appleton Laboratory. Physics in Collision Boston 27 th June. Contents. Asymmetric B factories BaBar and Belle CKM Matrix BaBar and Belle measurements of    BaBar and Belle Measurements of V cb V ub.

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CP Violation in B Decays and the CKM Matrix

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  1. CP Violation in B Decays and the CKM Matrix Emmanuel OlaiyaRutherford Appleton Laboratory Physics in CollisionBoston27th June Emmanuel Olaiya

  2. Contents • Asymmetric B factories • BaBar and Belle • CKM Matrix • BaBar and Belle measurements of •  •  •  • BaBar and BelleMeasurements of • Vcb • Vub Emmanuel Olaiya

  3. KEKB Collider Collider located in Japan Emmanuel Olaiya

  4. Belle Detector Aerogel Cherenkov cnt. n=1.015~1.030 SC solenoid 1.5T 3.5GeV e+ CsI(Tl) 16X0 TOF counter 8GeV e- Tracking + dE/dx small cell + He/C2H5 m / KL detection 14/15 lyr. RPC+Fe Si vtx. det. 3 lyr. DSSD Emmanuel Olaiya

  5. PEP II Collider Collider located on Stanford University grounds, USA Emmanuel Olaiya

  6. Superconducting Coil (1.5T) Silicon Vertex Tracker (SVT)[5 double-sided layers] e+ (3 GeV) e- (9 GeV) Drift Chamber [24 stereo lyrs, 16 axial lyrs](DCH) CsI(Tl) Calorimeter (EMC) [6580 crystals]. Cherenkov Detector (DIRC) [144 quartz bars, 11000 PMTs Instrumented Flux Return (IFR) [Iron interleaved with RPCs]. BaBar Detector Emmanuel Olaiya

  7. B Factory luminosities • Results from this talk are based on datasets of • Babar ≤ 113 fb-1 • Belle ≤ 140 fb-1 • At last look (22nd June) collected luminosities were • BaBar – 221.8 fb-1 • Belle – 280.0 fb-1 (Record luminosity!) Emmanuel Olaiya

  8. CKM matrix Cabibbo-Kobayashi-Maskawa(1973) matrix also in theWolfensteinrepresentation: CPV a e.g.: VudV*ub + VcdV*cb + VtdV*tb =0 A = 0.83 ± 0.05, l ~ 0.22 Alternative notation (f1, f2, f3) = (b, a, g) Emmanuel Olaiya

  9. q/p mixing CP Violation • CP violation can arise from interference in decay Direct CP violation CP violation through mixing For charmonium modes: Emmanuel Olaiya

  10. (1) Emmanuel Olaiya

  11. CP=-1 CP=+1 b→ccs Dt Dt sin2b from charmionium modes (b→ccs) + 140 fb-1 82 fb-1 sin(2b)= 0.741 ± 0.067(stat) ± 0.034(syst) sin(2b)= 0.733 ± 0.057(stat) ± 0.028(syst) Emmanuel Olaiya

  12. f B K “Naïve” flavor symmetry T/P |-hfSf – sin2b| j Ks 0.0 < 0.3 [2] h’Ks ~0.02 [1] < 0.4 [2] <~0.15[4] p0 Ks ~0.04 [1] < 0.2 [3] sin2b from bs penguins • B0 jKs , B0 h’Ks , B0 p0 Ks ,B0 f0Ks, • are dominated by b  s penguins • Penguin dominated decays provide the best possibility of observing new physics (NP) • New particles (e.g SUSY) can enter the loop • In SM we measure sin2beff ~ -hfSf • If Tree contribution is negligible we measure sin2b exclusively on penguins • Following analyses perform • t-dependent CP-asymmetries measurements • Maximum Likelihood [1] D.London and A.Soni, PLB 407, 61-65 (1997). [2] Y.Grossman, Z.Ligeti,Y.Nir, H.Quinn, PRD 68, 015004 (2003). [3] M.Gronau, Y.Grossman, J.Rosner, PLB 579, 331-339 (2004). [4] M.Gronau, J.Rosner, J.Zupan hep-ph/0403287 (2004). Emmanuel Olaiya

  13. B0gj KS/KL 110 fb-1 140 fb-1 B0 KS 68±11 events B0 KS 70±9 events B0  KL 52±16 events 3.5 deviation from SM +0.08 -0.06 +0.09 -0.11 SjK = 0.47 ± 0.34(stat) (syst) CjK = 0.01 ± 0.33(stat) ± 0.10(syst) SjK = -0.96 ± 0.50(stat) (syst) CjK = -0.15 ± 0.29(stat) ± 0.07(syst) hep-ex/040326 submitted to PRL PRL91,261801 (2003) Emmanuel Olaiya

  14. B0gK+ K- KS 110 fb-1 201±16 events -SKKKs = 0.56 ± 0.25(stat) ± 0.04(syst) CKKKs = -0.10 ± 0.19(stat) ± 0.10(syst) Asymmetry plot reversed 140 fb-1 199 ±18 events -SKKKs = 0.51 ± 0.26(stat) ± 0.05(syst) CKKKs = -0.17 ± 0.16(stat) ± 0.04(syst) Use high statistics outside j mass. CP state even state measured from: Garmash et al, Phys. Rev., D69, 012001 Emmanuel Olaiya

  15. 203  19 events 244  21 events Sh’ Ks = 0.02 ± 0.34(stat) ± 0.03(syst) Ch’ Ks = 0.10 ± 0.22(stat) ± 0.03(syst) Sh’ Ks = 0.43 ± 0.27(stat) ± 0.05(syst) Ch’ Ks = 0.01 ± 0.16(stat) ± 0.04(syst) B0gh’ KS 81.9 fb-1 140 fb-1 PRL 91, 161801 (2003) PRL 91, 261602 (2003) Emmanuel Olaiya

  16. 94  14 events Total Continuum All bgk. + 0.51 - 0.56 -Sf0 Ks =1.62 (stat) ± 0.09(syst) ± 0.04(model) Cf0 Ks = 0.27 ± 0.36(stat) ± 0.10(syst) ± 0.07(model) B0gf0(980) KS 111.2 fb-1 Mass measured is 981 ± 6 MeV/c2 S values is 1.2s from physical limit and 1.7s from SM Submitted to PRL Emmanuel Olaiya

  17. +0.38 -0.47 Sp0 Ks = 0.48 (stat) ± 0.09(syst) Cp0 Ks = 0.40 (stat) ± 0.06(syst) +0.27 -0.28 B0gp0 KS 110 fb-1 122±16 events hep-ex/0403001, submitted to PRL Emmanuel Olaiya

  18.  Measurements Emmanuel Olaiya

  19. Sin2 Comments • Sin2 measured from charmonium modes • Clear observation of CP violation • Good agreement between BaBar and Belle • Sin2 from charmless channels • Measurement has expanded to numerous rare decays • Interesting results on B0gj KS (Belle observe new Physics?) • Look forward to the analysis of larger datasets from both BaBar and Belle Emmanuel Olaiya

  20. (2) Emmanuel Olaiya

  21. Measuring a Both tree and penguin amplitudes contribute. M. Gronau, D. London, Phys. Rev. Lett., 65, 3381 (1990) Two triangular (isospin) relations can be constructed: If no penguins: With penguin contributions: Set a limit on the shift from penguins, a-aeff(useful only if the B→ h0h0 BR is small): Y. Grossman, H. R. Quinn, Phys. Rev., D58, 017504 (1998) Emmanuel Olaiya

  22. B0 tags B0gp+p- 266  24 events 81 fb-1 PRL 89 281802 (2002) B0 tags The B0→ p0p0 BR was measured at BABAR,PRL 91 241801 (2003),and at Belle. HFAG glarge penguin contributions: |a-aeff |<48o (90% cl) 113 fb-1 PRL 91 201802 (2003) Emmanuel Olaiya

  23. high LR low r (flavor tag quality) good poor B0gp+p- 140 fb-1 Evidence for direct CP violation? Emmanuel Olaiya

  24. B0gp+p- crosschecks World average (PDG2003) (1.537  0.015) ps pp : tB=(1.47  0.09) ps Kp : tB=(1.52 0.06) ps Background shape fits to continuum Null asymmetry SKp = 0.14  0.11 CKp = -0.02  0.08 Emmanuel Olaiya

  25. Cpp Spp B0gp+p-  (degrees) CL=0.683 (1) CL=0.955 (2) CL=0.9973 (3) Feldman-Cousins Analysis  (degrees) • Evidence for direct CP violation • 3.2 from C=0 and any S 90 ≤ ≤ 146 (95.5% CL) Emmanuel Olaiya

  26. r+r- and the Grossman-Quinn bound small BR! penguin dominated HFAG Exploit the Grossman-Quinn bound to limit Da=|a-aeff| and explore the feasibility of the measurement: B0  + - is a Vector-Vector decay g the decay can proceed through 3 helicity amplitudes: l=0 → longitudinal polarization. Pure CP even eigenstate. l=±1→ transverse polarization. Mix of CP even and odd eigenstates. The decay B0  + - has been observed at BaBar and its BR and polarization measured: (PRD 69, 031102 (2004) and hep-ex/0404029, submitted to PRL) Emmanuel Olaiya

  27. Full likelihood Background Data B0gr+r- - CP Asymmetry Results 113 fb-1 all B tags cleaner B tags mES Dt DE Emmanuel Olaiya

  28. B0gr+r- - Measurement of a From Isospin Analysis preliminary B0+- information provides new value in the CKM fit Emmanuel Olaiya

  29. B0gr+r- - Measurement of a Confidence level contours from CKM fit The B system provides the most stringent constraint on  ignores non-resonance contribution and interference with other 4p modes and assumes no I=1 contribution Emmanuel Olaiya

  30. Comments on a • Direct CP violation evidence at Belle through B0gp+p- • Cp+p- = -0.58 ± 0.15 ± 0.07 • No evidence with the same mode at BaBar • Cp+p- = -0.19 ± 0.19 ± 0.05 • New constraint on a measured at BaBar through B0gr+r- Emmanuel Olaiya

  31. (3) Emmanuel Olaiya

  32. Color suppressed B-gD(*)0K(*)-  can be measured from interferences between (b→u) and (b→c) decay amplitudes Gronau-London-Wyler Method Dd=difference of strong phases betweenB+D0 K+andB-D0 K- (modified) Gronau-London-Wyler (Phys. Lett. B253, 483 (1991); Phys. Lett. B265 172 (1991)) Emmanuel Olaiya

  33. B-gD0K- Results Gronau Phys.Lett. B557, 198 81 fb-1 78 fb-1 R+ = 1.21 ± 0.25 ± 0.14 A+ = 0.06 ±0.19 ± 0.04 R- = 1.41 ± 0.27 ± 0.15 A- = -0.19 ±0.17 ± 0.05 R+ = 1.06 ± 0.19 ± 0.06 A+ = 0.07 ±0.17 ± 0.06 PRL 92, 202002 PRD 68, 051101 Emmanuel Olaiya

  34. B-gD0K- Dalitz • If both D0 and anti-D0 decay into the same final state, B+ →D0K+ and B+→anti-D0K+ interfere • Mixed state is • Phase + is the sum of the weak and strong phases + • Use 3-body final state which is identical for D0 and anti-D0 (Ks+-) • If final model D0 Ks+-) is known, the parameters r and  can be extracted from a Dalitz plot analysis • For B-gD0K- decay, weak phase of color suppressed amplitude changes sign, yet the strong phase is unchanged, -= - • Can extract r,  and  with a simultaneous fit to B+ and B- data Emmanuel Olaiya

  35. B-gD0K- Dalitz Study D*→D0π– decays and obtain D0→Ksπ+π– Dalitz parameters 101800 events in data D0→Ksπ+π– Dalitz fit Emmanuel Olaiya

  36. B-gD(*)0K- Dalitz In the absence of CP violation, the number of B+ and B- events should be the same Fit the D0→Ksπ+π– Dalitz plot for BD*(0)K- decays and extract  BD0K+ 73 events BD0K- 73 events =81±20 @68 CL 37<  <135 @95 CL BD*0K+ 20 events BD*0K- 19 events =57±47 @68 CL -31<  <133 @95 CL Emmanuel Olaiya

  37. Dominant decay : (b → c) transition Suppressed decay : (b → u) transition γ mixing : 2β sin(2b+g) with B-gD(*)0p- High Statistics, no Penguins but small CP Asymmetry Emmanuel Olaiya

  38. sin(2b+g) with B-gD(*)0p- a c -0.022 ± 0.038 ± 0.020 0.025 ± 0.068± 0.033 -0.068 ± 0.038 ± 0.020 -0.031 ± 0.070 ± 0.033 D0 D*0 |sin(2b+g)| > 0 at 99.4% CL |sin(2b+g)| > 0.58 at 95% CL a c -0.062 ± 0.037 ± 0.016 0.025 ± 0.037± 0.018 -0.060 ± 0.040 ± 0.017 -0.049 ± 0.040 ± 0.019 D0 D*0 a c -0.043 ± 0.029 0.014 ± 0.036 -0.037 ± 0.021 0.022 ± 0.028 D0 D*0 AVERAGE Emmanuel Olaiya

  39. Comments on  • Current B factories are now producing  measurements • Different methods for measuring , eg. B-gD0K- , B-gD0- • Precision limitation is mainly statistical Emmanuel Olaiya

  40. Vcb & Vub Emmanuel Olaiya

  41. Vcb and Vub with Semileptonic decays • Semileptonic B decays provide best method for determination of |Vcb| and |Vub| • transition matrixelement M factorizes : • leptonic current (W* l n ) , Mlep (easy) • hadronic current (b  W* c), Mhad (QCD , hadronic uncertainties) • Theoretical framework : HQE • expand Mhad in powers of 1/mb in terms of local operators • matrix elements of these operators ("mG2 " , "mp2 "...) represent properties of b quark in B meson ( kinetic energy , chromomagnetic coupling to gluon spin) • perturbative corrections to coefficients • HQE  • No locally exact predictions of dG/dEe or dG/dMx (singularities) • However, problems cancel "on average"  Moments, for example Emmanuel Olaiya

  42. Vcb and Vub with Semileptonic decays Inclusive El spectrum Rate Semileptonic B decay Shape  |Vcb|2,|Vub|2 El[GeV] Inclusive Mx spectrum shape Shape (log-scale) Rate for Mx<1.55 Emmanuel Olaiya

  43. m=1 GeV/c, scale which separates effects from long- and short-distance dynamics r = mb/mc , z0 = tree-level phase space factor , Apert = pert. corrections (as , as2b0) Lepton energy spectrum Mass of hadronic system Semileptonic B Decays & HQE • Relation between inclusive decay width and |Vcb| : • contains b- and c-quark masses mb and mc (at m=1GeV) mp2 related to kinetic energy of b-quark in B meson mG2 related to chromomagnetic coupling of b-quark to spin of gluons • B / B* mass splitting • two more parameters at order 1/mb3 • Darwin term ( ) and spin-orbit interaction ( ) • Problem: Large uncertainties in mb,mc, m‘s, r‘s • Solution : HQE predictions of moments of incl. distributions Emmanuel Olaiya

  44. high correlation between measurements : this fit uses solid points only Simultaneous Fit to Ee and Mx Moments • |Vcb| "master" formula : • : • i-th central El moment for El>E0: • i-th Mx moment and El>E0 : 82 fb-1 Calculations taken from Gambino and Uraltsev, hep/ph 0401063 Emmanuel Olaiya

  45. Fit Results To be submitted to Phys. Rev. Lett. kinetic mass scheme Strong correlation between mb and mc: mb(1 GeV) – mc(1 GeV) = (3.44±0.03exp±0.02HQE±0.01αs) GeV BABAR BABAR 2D projections of the fit result: BABAR Δχ2=1 ellipses Emmanuel Olaiya

  46. Results Overview BB Xl  Emmanuel Olaiya

  47. B Xul n Results • Events with fully reconstructed hadronic B decay • lepton with p* > 1 GeV/c • veto on K+, K0s decays • m2miss < 0.5 GeV2/c4 , Qtot = 0 82 fb-1 • Inclusive Mx spectrum : • Use shape function for extrapolation • F. De Fazio, M.Neubert JHEP 9906, 017 (1999) • Extraction of |Vub| : • formula from CKM 2002 workshop : • Extract number of signal eventswith Mx<1.55 GeV/c2 by fitting sumof 3 shapes to full Mx distribution : • signal • b c l n background • other sources (<1%) • misidentified leptons • t and secondary charm decays with tB=(1.608  0.016) ps Ongoing discussion on how to improve understanding of theoretical error on shape function error due to extrapolation and efficiency error of transition G(BXu l n)  |Vub| (Uraltsev, Hoang) Emmanuel Olaiya

  48. B Xul n: Results 78 fb-1 Mb = 4.80 ± 0.12 • Extract number of signal eventswith Mx<1.7 GeV/c2 and q2 > 0.8 GeV : • b c l n background floated in the fit • 1376 ± 167 signal events • 7283 ±130 background evensts Emmanuel Olaiya

  49. Comments on Vcb and Vub • New results on Vcb and Vub from B factories • Twice the data sample used available for updates • However precision limitation is mainly theoretical. Emmanuel Olaiya

  50. Summary • CP violation is now well established in the B sector thanks to Belle and BaBars charmonium measurements of sin2b • Measurement have expanded to charmless penguins, B0 jKs , B0 h’Ks , B0 p0 Ks ,B0 f0Ks • New physics observed with B0 jKs ? • Await analyses on larger datasets with great interest • Better bounds on  using B0gp+p-,B0gr+r- • Evidence for direct CP violation in B0gp+p- • Await analyses on larger datasets with great interest • B factories now producing  results • Over to theorists to help improve the precision measurements of Vcb and Vub • The sin2b measurements have been a huge success and the B factory experiments have shown that there is still a large amount of interesting physics in progress Emmanuel Olaiya

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