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L.Lista INFN Sezione di Napoli

L.Lista INFN Sezione di Napoli. Rare and Hadronic B decays in B A B AR. Outline. Charmonium decays Inclusive Exclusive J/  K* angular analysis Open Charm 2-body hadronic decays quasi 2-body decays Radiative penguin. Inclusive Charmonium Decays. B-counting: Correct by  (4S)

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L.Lista INFN Sezione di Napoli

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  1. L.ListaINFN Sezione di Napoli Rare and Hadronic B decays in BABAR Luca Lista

  2. Outline • Charmonium decays • Inclusive • Exclusive • J/ K* angular analysis • Open Charm • 2-body hadronic decays • quasi 2-body decays • Radiative penguin Luca Lista

  3. Inclusive Charmonium Decays • B-counting: • Correct by (4S) • 1.6% sys. Error • 22,700,000 BB events Lepton identification • Bremstrahlung-recovery for electrons • Background rejection: • At least 3 tracks, Etot > 4.5 GeV • Ratio of 2nd to 0th Fox-Wolfram moment R2< 0.5 Luca Lista

  4. Inclusive Charmonium: J/ • Inclusive branching ratio: • Br(BJ/X) = (1.0440.013 0.028)10-2 • Br(BJ/X dir.) = (0.7890.010 0.034)10-2 • J/ momentum distribution measured • Y(4S) system = B system  250 MeV • Polarization -0.4240.023 (-1 = longitudinal) • Signal from continuum subtracted ( …) J/ l+l-, l= e,  p*J/ < 2 GeV/c Luca Lista

  5. mode resonance p* cut (GeV/c) yield mm on >2 87952 ee on >2 79962 mm off - 15625 ee off - 12126 J/ production in continuum Not a B decay, but a new BaBar result… • First observation of J/ production in continuum • Rejection of BB (p*>2 GeV/c) • Rejection of ISR (Ntracks, Etot, R2) • Angular distribution: 1+Acos2q* • A(all E*) = 0.250.19 • A(p*>3.5 GeV) = 0.620.39 • Color singles: A  –0.8,  2.8 pb • NDQCD (c.o): 0.6<A<1.0,  0.8 pb Luca Lista

  6. Inclusive Charmonium: (2S) • Br( B (2S) X ) = (0.2750.020 0.029) 10-2 • (2S)  l+l- branching ratio • Assuming PDG values for (2S)J/+- (2S) l+l-, J/+- p* < 1.6 GeV/c Luca Lista

  7. Inclusive Charmonium: c • Br(B c1 X) = (0.378 0.034 0.026)10-2 • Br(B c1 X dir.) = (0.353 0.034 0.024)10-2 • Br(B c2 X) = (0.137 0.058 0.012)10-2 < 0.2110-2 @ 90% C.L. c2 (?) c2 (?) Luca Lista

  8. Exclusive decays • Several CP channels • sin2b • Direct CP asymmetry • Kinematics selection: • Energy substituted mass • Independent on particle mass hypotheses • Energy difference in the center of mass Example: B-D0- DE (GeV) mES (GeV/c2) Luca Lista

  9. BJ/K0S Luca Lista

  10. BJ/K0L • KL reconstructed as neutral deposit in the IFR or E.M. Calorimeter • 1.4 < p*J/ < 2.0 GeV/c • No momentum measurement • DE is measured assuming the mBmass constraint Luca Lista

  11. Selected channels First observation Luca Lista

  12. Branching rations results Luca Lista

  13. BaBar compared to PDG 2000 Luca Lista

  14. +1.9 ( 5.0  0.1 ) % -1.7 J/+ / J/K+ • Cabibbo and color suppressed tree diagram • possible CP asymmetry from penguin contribution • Unbinned maximum likelihood fit based on kinematical variables: • Br(B+J/K+)/(B+J/+) =(3.910.78 0.19)10-2 ( 5.2  2.4 ) % ( 5.1  1.4 ) % Luca Lista

  15. J/ K* angular analysis • f (costr, cosK*, tr) = f1 |A0|2 + f2 |A|||2 + f3|A|2f4 Im(A||* A) + f5 Re (A0* A||) + f6 Im (A0* A) Channels withoutp0 Channels withp0 J/ rest frame K* decay plane |A|2 + |A|||2 + |A0|2 = 1 Luca Lista

  16. J/ K* angular analysis Indication of FSI (a) Raw measurement (b) Acceptance correction (c) “ “ + mES fit (d) “ “ + (Self) Feed Across CP asymmetry dilution factor: D =1 – 2|A|2 = 0.680.10 Luca Lista

  17. BD*+p-, D*+r- • May exhibit small CP asymmetries • Potential for sin(2b+g) and • Reconstruct the decay chains: • B reconstruction efficiencies estimated with MC Luca Lista

  18. BD*+p- Br(BD*+p-) = (2.9 ± 0.3 ± 0.3 )10-3 PDG:(2.76 ± 0.21)  10-3 Luca Lista

  19. BD*+r- Br(BD*+r-) = (11.2 ± 1.1± 2.5 )  10- 3 PDG: (6.8 ± 3.4)10-3 Luca Lista

  20. B  D*+D*- • Independent measurement of sin2b • D*+D+p0, D0p+ • D0K-p+, K-p+p0, K-p+p+p-, KSp+p- • D+ K-p+p+, KSp+, K-K+p+ • B decays with two p0 are not used • High background, low branching fraction • Many possible combinations in the same event. Chosen the one which minimizes: Luca Lista

  21. B  D*+D*- Br(BD*+D*-) = (8.0 1.6  1.2)10-4 Luca Lista

  22. B  D*D(*)K • bccs transition • D*+ D0p+; • D*0 D0p0 • D*0 D0g • D0 K-p+, • D0 K-p+p0 • D0 K-p+p-p+; • D+ K-p+p+; • Br(B0 D*+D0K+) = (0.280.070.05)10-2 • Br(B0 D*+D*0K+) = (0.680.170.17)10-2 • Br(B+ D*+D*-K+) = (0.340.160.11)10-2 • First observation of non-charmonium color suppressed mode B0 (all modes) NS = 18021 B+ (all modes)NS = 11715 B+ D*+D*-K+ NS = 8.23.5 Luca Lista

  23. u d d u d d Charmless Hadronic Decays • Physics motivations • Significant penguin contribution • Direct CP violation studies • Measurement of  from time-dependent asymmetry + isospin analysis • Possible field for new physics… Cabibbo suppressed }p-(K-) Vud(s) d(s) W- Vub { b }p+ u B0 Penguin diagram }p-(K-) Vtd(s) W- d(s) Vtb }p+ { b u t B0 Luca Lista

  24. Identifying K and p • Particle identification in the DIRC D*+D0, D0K-+ control sample Luca Lista

  25. Background Rejection • Continuum events rejection • Fisher discriminator on event shape • Thrust axis (B vs rest of event) • Background control samples • DE sidebands • Off-resonance data • D*+D0, D0K-+control sample background D0+ on reson. mES<5.26   signal background signal Luca Lista

  26. Two Body Charged Modes Cut based selection • Bh+h- p+p- UML Fit results K+p- K+K- Luca Lista

  27. Two Body Charged + Neutral Modes Cut based projections • Bp0h+ p0p+ UML Fit results p0K+ Luca Lista

  28. BK0h+,K0p0 Cut based projections K0p0 K0p+ K0K+ Luca Lista

  29. Charge Asymmetries • K+p- A = - 0.190.100.03 [ -0.35, -0.03 ], 90%C.L. • K+p0 A = 0.000.180.04 [ -0.30, +0.30 ], 90%C.L. • K+p- A = - 0.210.180.03 [ -0.51, +0.09 ], 90%C.L. • All asymmetries compatible with 0 within current errors Luca Lista

  30. Quasi 2-body and 3-body decays B+h+ < 24  10-6 ( 90% C.L. ) B0K0 < 14  10-6 B+K+ ( 62  18  8 )  10-6 B0K0 < 112  10-6 B0K*0 p+ < 28  10-6 B+0K+ < 39  10-6 B+0p+ < 39  10-6 B+K+p+p- < 54  10-6 B+p+p+p- < 22  10-6 B0p ( 49  13+6-5 )  10-6  Luca Lista

  31. BK, BK* • Penguin dominated • Measure of sin2b B+K+=(7.7+1.6-1.40.8)  10-6 B0 K0 =(8.1+3.1-2.50.8)  10-6 B+K*+ =(9.7+4.2-3.41.7)  10-6 B0K*0 =(8.6+2.8-2.41.1)  10-6 B0p+<1.4 10-6(90% C.L.) Luca Lista

  32. B  K* • Sensitive to top quark couplings • CKM matrix elements Vtd,Vts • Sensitive to New Physics • SUSY, Charged Higgs • No CP asymmetry in the Standard Model • Possible sources beyond SM Signal: B0 K*0, K*0 K+- Backgrounds: e+e- qq  e+e- qq  X 0 Luca Lista

  33. B  K*: yield and branching ratio • Nsignal = 139.2  13.1 events • Br(B0 K*0)= (4.39  0.41)  10-5 • Br(B K+e+e-) < 12.8  10-6 • Br(B K+m+m-) < 8.3  10-6 • Br(B K*0e+e-) < 24.7  10-6 • Br(B K*0m+m-) < 25.7  10-6 (90% C.L.) Luca Lista

  34. B  K*: CP asymmetry • K*0K+p- • N(B0) = 72.1  9.4 events • N(B0) = 67.2  9.1 events • ACP = -0.035  0.09 K*0  - K*0  Luca Lista

  35. bs, B  PRELIMINARY • Semi-exclusive study • Sum of exclusive modesK+np (n=1,2,3) • B(B0) < 1.94 x 10-6 90% C.L. • PDG: B(B0 ) < 3.9 x 10-5 90% C.L. (from L3) mES for 0.6 <mhad < 2.0 GeV 668  53 events Luca Lista

  36. Conclusions • Many branching ratios have been measured in BaBar • Some are newly observed signals • Potential for more CP violation studies • More statistics will permit to measure CP asymmetries • Stay tuned! Luca Lista

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