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Review of BaBar results

Review of BaBar results. L.Lista INFN - Napoli. Outline. PEP-II and BaBar experiment CP Violation: Direct CP violation Measurements of sin2 ,  and  Measurements of |Vub| and |Vcb| Searches beyond the Standard Model Conclusions Many results skipped due to limited time….

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Review of BaBar results

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  1. Review of BaBar results L.Lista INFN - Napoli Luca Lista, HEP-MAD 2004

  2. Outline • PEP-II and BaBar experiment • CP Violation: • Direct CP violation • Measurements of sin2,  and  • Measurements of |Vub| and |Vcb| • Searches beyond the Standard Model • Conclusions • Many results skipped due to limited time… Luca Lista, HEP-MAD 2004

  3. PEP-II: Luminosity and Data Sample Total: 244 fb-1 (Jul 31st 04) • PEP-II is SLAC e+e-B factory running at the Y(4S) c.m. energy • Y(4S) resonance decays to charged and neutral B-anti-B pairs Luca Lista, HEP-MAD 2004

  4. BaBar Detector EMC 6580 CsI(Tl) crystals e+ (3.1GeV) 1.5T solenoid DIRC(PID) 144 quartz bars 11000 PMs Drift Chamber 40 layers e- (9GeV) Silicon Vertex Tracker 5 layers, double sided strips Instrumented Flux Return iron / 18/19 planes of RPCs (muon / neutral hadrons) Luca Lista, HEP-MAD 2004

  5. A=(,)   B=(1,0)  C=(0,0) The Unitarity triangle • CKM matrix measures Quarks mixing in weak interactions • Unitarity relations lead to unitarity triangles in the complex plane 1 B and  (bcl) Luca Lista, HEP-MAD 2004

  6. q/p q/p  A 2 2  CP Violation (I, II) CP first observedin kaon decays CP violation in mixing q and p are the mass eigenstates coefficients in the flavor eigenstate basis; M - i½  is the 22 effective Hamiltonian SM prediction for B mesons is very small: Direct CP violation in the decay If B decay amplitude to f is different from anti-B decay amplitude to anti-f. Requires a relative CP violating phase 2 and a CP conserving phase 2 Luca Lista, HEP-MAD 2004

  7. B0 fCP t d b B0 B0 B0 W W t b d CP Violation (III) Time dependent CP Asymmetry: Time dependent CP violation For a single amplitude Luca Lista, HEP-MAD 2004

  8. mES signal region DE sidebands mES (GeV) B decay reconstruction and tagging B kinematics Inclusive tag (lepton, K, …):tag(1-2w)2 30% Exclusive tag: tag  0.10.2% tag Typical resolutions: s(mES)  2.5 MeV s(DE)  15 - 30 MeV CP rec  1540% < z >  260 m z (RMS)  150 m Luca Lista, HEP-MAD 2004

  9. Direct CP Violation hep-ex/0408057, submitted to PRL on Signal: 160651 events (227106 BB pairs) B0K BABAR B flavor is tagged by the kaon charge AK = -0.1330.0300.009 (4.2) Tree + Penguin contributions First observation of CP violation in B meson decays! BK0 Pure Penguin AK = 0.060.060.01 E (GeV) Luca Lista, HEP-MAD 2004

  10. (cc) KS (CP odd) modes CP Violation in Mixing-Decay interference J/ψKL (CP even) mode S = sin2 = 0.722  0.040  0.023 C = || = |A/A| = 0.950  0.031 0.013 7730 tagged CP events on 227106 BB pairs =205fb-1 on peak Measured on a variety of cc decay modes Direct CP violation if  1 Luca Lista, HEP-MAD 2004

  11. sin2 in the Unitarity Triangle plane cos2b > 0 at 87% C.L. Using an s- and p-wave interference in angular analysis of BJ/yK*0 (KSp0) Luca Lista, HEP-MAD 2004

  12. “sin2” channels probing new Physics B0K0S B0K0S0 • Decays dominated by loop diagrams can exhibit contributions from new physics B0K0S ? Signal: 81938 events 3 deviation from charmonium sin2 Luca Lista, HEP-MAD 2004

  13. Comparison of sin2 modes 2.7 from s-penguin to sin2 (cc) 2.4 from s-penguin to sin2 (cc) Luca Lista, HEP-MAD 2004

  14. Measurement of sin2 Interference of suppressed b  u “tree” decay with mixing Penguin diagrams may be of the same magnitude. B0 decay: penguin B0 mixing B0 decay: tree Isospin analysis could measure the amount ofcorrection to  Luca Lista, HEP-MAD 2004

  15. sin2 with B 227106 BB pairs B0 S = -0.30  0.17  0.03 C = -0.09  0.15  0.04 Particleidentificationis fundamental C (rad) p (GeV/c) B(B0) = (5.80  0.06  0.40)10-6 A0 = -0.01  0.10  0.02 B(B000) = (1.17  0.32  0.10)10-6 C00 = -0.12  0.56  0.06 |-eff| < 35° 90% C.L. (Gronau, London) Belle observes C00 = -0.58  0.15  0.07 … Luca Lista, HEP-MAD 2004

  16. 89106 BB B(B0) = (22.5+5.7-5.4  5.8)10-6 B(B000) < 1.110-6 (90% C.L.) 277106 BB sin2 with B 122106 BB pairs • Similar to , but smaller penguin pollution • Not a CP eigenstate in principle, but observedto be almost pure CP = +1 B0 Slong = -0.19  0.33  0.11 Clong = -0.23  0.24  0.14  = ( 96  10(stat) 4(sys) 11(peng) )° (Grossman, Quinn) Luca Lista, HEP-MAD 2004

  17. Combined B, ,  (Dalitz) “mirror” solutions become disfavored From CKMmatrix fit (with no  meas.):  =( 98  16 )° Fit + , , :  =( 103 +10-11 )° Luca Lista, HEP-MAD 2004

  18. Different methods to measure  GLW • The phase between bc and bu transitions is  Size of CP asymmetry depends on: Color suppressed • Gronau, London, Wyler, 1991: use B-D0CP (small D0 B.r., 8-fold ambiguity) • Atwood, Dunietz, Soni, 2001: interference in D and anti-D dec. to same final state • Giri, Grossman, Soffer, Zupan, 2003: B- D(*)0K-, D0 KSp+p- Dalitz analysis input: dB dD BABAR measurement,Phys.Rev.Lett.91:171801,2003 Luca Lista, HEP-MAD 2004

  19. B-D(*)0K-, D0K+p- ADS method No signal observed in 227106 BB pairs  AADS not measured, limits on RADS Any D, 1 on rD, 48°<<73° RADS Any  D*D00, D0 68% C.L. area 90% C.L. Upper limit 68% C.L. area rB* rB Small rB values make measuring  hard Luca Lista, HEP-MAD 2004

  20. B- D(*)0K-, D0 KSp+p-Dalitz analysis 68% 90% A posteriori rB(rB*) with uniform a priori g [deg] g [deg] Dalitz model syst. Sensitivity depends on rB(*) D*D00, D0 Luca Lista, HEP-MAD 2004

  21. Time-dependent CP violation in the mixing/decay interference sin(2+ ) using B0D(*)-p+/r+ ~l2 ~l4 favored bc amplitude suppressed bu amplitude Time-dependent asymmetry can be expressed in termof the parameters: a = 2rsin(2)cos c = 2rcos(2)sin Exclusivereconstruction of D-p+, D*-p+,D-r+ No CP asymmetry observed yet… Partialreconstruction of D*-p+ Luca Lista, HEP-MAD 2004

  22. Vcb inclusive measurement • Inclusive B → Xc l  decays: measurehadron mass moments and lepton energy moments Lepton energy momenta Partial B.F. HQE predicts the moments up to 8 parameters to be fitted (including |Vcb|, mb and mc) B (b→ cl)=(10.61 ± 0.16exp± 0.06th,HQE,)% Luca Lista, HEP-MAD 2004

  23. Vcb: HQE Fits to MX / El moments ● = used, ○ = unusedin the nominal fit BABAR MX moments M1x M2x M4x M3x M0l M3l M1l M2l Red line: HQE fitYellow band: theory errors c2/ndf = 20/15 Eℓmoments Luca Lista, HEP-MAD 2004

  24. Vcb exclusive measurements • Exclusive B → D*+l n Decays w = prod. B, D* 4-velocities B (B0→ D*- l+ )=(4.90 ± 0.07stat± 0.36syst)% Luca Lista, HEP-MAD 2004

  25. Vub measurements • Exclusive: measure selected decays (B l, l, …) • Innovative technique: fully reconstruct one of the B • Inclusive: measure total Br(bul) B(B0-l+)=(1.080.280.16)10-4 B(B+0l+)=(0.910.280.14)10-4 B(B0-l+)=(2.570.520.59)10-4 Electron endpoint spectrum extrapolation using bs photon spectrum (CLEO) using HQET B(BXue)=(1.730.22exp0.33extr.syst)10-3 p (GeV/c) |Vub| = (3.940.25exp0.37extr.syst 0.19th) 10-3 Luca Lista, HEP-MAD 2004

  26. Vcb and Vub averages Exclusive modes LEP Inclusive studies |Vub|avg. = (4.700.44stat+sys)10-3 |Vcb|avg. = (41.40.4 0.4 0.6th)10-3 Luca Lista, HEP-MAD 2004

  27. Radiative penguin decays Radiative penguin decays: b → s and b → d are FCNC transitions b → s rate agrees with SM prediction: W could be replaced in the loop by new particles BF(b→s)TH = 3.57 ± 0.30 x 10-4 (SM NLO) BF(b→s)EXP = 3.54 ± 0.30 x 10-4 (HFAG average) b→d at discovery limits: BF(B → r,w g) < 1.2  10-6 |Vtd/Vts| < 0.19 (90% CL) Sum of 12 exclusive, self-tagging B→Xsg final states Xs = K/Ks + 1-3 pions Eg* > 2.14 GeV b→sg b→sg No evidence of direct CP violation: ACP, bs = 0.025 ± 0.050 ± 0.015 ACP, BK* = -0.013 ± 0.036 ± 0.010 (prelim.) Luca Lista, HEP-MAD 2004

  28. Studies of DsJ properties DsJ(2460)+Ds+ elicity • DsJ*(2317)+ and DsJ(2460)+ discovered in 2003 • Detailed studies properties and mass meas. • BDsJ(*)+D(*) angular analysis  spin • Branching fraction measurements J=2 J=1 Ds1(2536)+ DsJ(2460)+ DsJ*(2317)+ m(DsJ*(2317)+Ds+0) = 2318.90.30.9 MeV/c² m(DsJ(2460)+ Ds+, Ds+ 0, Ds++ -) =2459.40.31.0 MeV/c² m(Ds1(2536)+  Ds++ -) =2534.30.41.2 MeV/c² m(Ds++ -), GeV/c² Luca Lista, HEP-MAD 2004

  29. Conclusions • BaBar is exploring different aspects of CP violation in B meson • Recent first evidence of direct CP violation • sin2 is becoming a precision measurement • First quantitative estimates of  • Technology for extracting  is being established • Some channels may probe new physics • bsss penguins? • The increase of statistics in the following years will improve the experimental precision and will make more rare channels accessible Luca Lista, HEP-MAD 2004

  30. 5 Lc+(2285) 5 5 5 5 Pentaquark searches • No evidence of pentaquarks in high statistics samples • Cross section limits well below expectations 5--(1862) 123fb-1 No signal for 5-- 50(1862) 5+(1540) nK+ No signal for 50 No signal for 5+ m(pKS) (GeV/c2) pKS Luca Lista, HEP-MAD 2004

  31. Backup Luca Lista, HEP-MAD 2004

  32. Selex DsJ(2632)+ state • SELEX claims evidence of a state DsJ(2632)+ decaying to Ds+ and D0K+(hep-ex/0406045) • BaBar doesn’t observe such signal DsJ(2573)+ DsJ(2632)+ Events/5 MeV/c2 Events/5 MeV/c2 SELEX M(D0K+) GeV/c2 Dm = M(K-p+K+)– M(K-p+) MeV/c2 p* > 4.0 GeV/c Luca Lista, HEP-MAD 2004

  33. Selex DsJ(2632)+ state (Ds+ ) No evidence of DsJ(2632)+ in Ds+, D0K+, D*+KS in125 fb-1 Luca Lista, HEP-MAD 2004

  34. J/yp+p-resonance at 3782 MeV/c2 mX(3782)=3873.4±1.4 MeV/c2 Ny(2S)=556±30 No evidence of hc found Set an upper limit B(B-→hcK-)∙ B(hc→J/yp+p) <3.4 ∙10-6 (90% C.L.) y(2S) hc X(3782) B(B-→X(3872)K-) ∙ B(X(3872)→J/yp+p-)=(1.28±0.41)∙10-5 Luca Lista, HEP-MAD 2004

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