1 / 46

Results from Belle and BaBar

Results from Belle and BaBar. Paoti Chang National Taiwan University Hadron Collider Physics Symposium 2005 4-9 July 2005, Les Diablerets, Switzerland. CP Violation and CKM Matrix. CPV in SM arises from an irreducible complex phase. Is there only one weak phase?

gloria-barron
Download Presentation

Results from Belle and BaBar

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Results from Belle and BaBar Paoti Chang National Taiwan University Hadron Collider Physics Symposium 2005 4-9 July 2005, Les Diablerets, Switzerland P. Chang

  2. CP Violation and CKM Matrix • CPV in SM arises from an irreducible complex phase. • Is there only one weak phase? • B meson properties – Establish CPV in 2001 by Belle and BaBar – Precise measurement of SM parameters – Search for TCPV in other processes – Direct CP violation and rare decay P. Chang 2

  3. _ B0 m+ J/Y m- B1 (4S) KS fCP e+ nm p- B2 K+ B0 p- m+ Flavor tag Dz ~ 200mm Asymmetric e+e- Collider Piermaria Oddone e- P. Chang 3

  4. B Factory Performance Belle: Peak luminosity= 1.58 *1034 cm-2 s-1; ~ 1 fb-1/day BaBar: Peak luminosity~ 1 *1034 cm-2 s-1 Unexpected Shut down P. Chang 4

  5. Superconducting Coil (1.5T) Silicon Vertex Tracker (SVT)[5 layers] e+ (3 GeV) e- (9 GeV) Drift Chamber [40 stereo 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 P. Chang 5

  6. Belle Detector Aerogel Cherenkov cnt. n=1.015~1.030 SC solenoid 1.5T 3.5GeV e+ CsI(Tl) 16X0 TOF counter 8GeV e- EFC m / KL detection 14/15 lyr. RPC+Fe Si vtx. det. 3/4 lyr. DSSD P. Chang 6

  7. Results • Measurements on the unitarity triangle – sin(2f1/b) from b  ccs –sin(2f1/b)eff from b sss – f2/a and f3/g • Rare Decays and Direct CP Violation – B → t n – Radiative B decays – Hadronic B decays • See Abe and Forti’s talks @LP05 for Vub measurements and other results. P. Chang 7

  8. Mixing Induced CP Violation Asymmetry occurs due to the interference between B0→ f and B0→ f. Theoretically clean measurement from J/y KS and other b →ccs decays. Sf= sin2f1for J/y KS P. Chang 8

  9. sin2f1/sin2b from B → J/y K0 Nsig =5264  73 Nsig =4792  105 P. Chang 9

  10. sin2f1/ sin2b Continue • HFAG Winter 2005 average: • Belle summer update (386 M BB pairs): • HFAG New average (preliminary) P. Chang 10

  11. Four-fold Ambiguity of f1 –sign ambiguity from the two choices of strong phases. – BaBar resolves the ambiguity by examining the S wave and p wave interference near K*0(89 M BB). – Belle assumes s-quark helicity conservation. P. Chang 11

  12. Belle f1 Extraction from B0→D0h0 P. Chang 12

  13. f(m+,m-) Determination 2 2 • Using inclusive D*- →D0p- –Distinguish D from the sign of slow p – Express f in sum of resonances (18) and non-resonant amplitudes –Perform unbinned likelihood fit D0→ KSp+p- P. Chang 13

  14. Time dependent Dalitz Analysis Perform fit using 309 ± 31 events with 63% purity Dp0 (157 ± 24),Dw(67 ±10), D h (58 ± 13), D*p0/D*h (27±11) More K*+ Than K*- Belle Preliminary P. Chang 14

  15. Dream of New Physics with CPV in Rare Decays • In the SM for the pure bs transition, sin(2 1)eff (bsss)≈ sin(2 1)(bccs) • Any large deviation may mean new physics. • Decay Modes: B  KS ; B KS ; B KKKS;KsKsKs B f0 KS, wKS,KSp0 • Theoretically deviation between the two processes can be as low as ~ 5%. P. Chang 15

  16. Results in last summer sin2f1(bgsqq) = 0.39  0.11 (Belle) 0.42  0.10 (BABAR) World Average (WA) sin2f1(bgsqq)= 0.41  0.07 sin2f1(bgccs) = 0.726  0.037 CL = 1.2 10-4 (3.8s) P. Chang 16

  17. fKS , fKL andKKKS Signals 180 16 536  29 114±12 98± 18 78 13 399±28 New P. Chang 17

  18. Fit Results of fKS , fKL andKKKS P. Chang 18

  19. BaBar Measurement on KSKSKS 0 0 0 • Allow at most one KS→ p0p0. • Find ZCP from the interception of three Ks tracks with IP constrained fit. • Z resolution is dominated by tagged side vertex. Nsig= 88 10 P. Chang 19

  20. Belle Measurements on hKS and hKL 0 0 Nsig =830  35 Nsig =187  18 Belle hK0 : “sin2f1”= 0.62 0.12 0.04 C = 0.04 0.08 0.06 BaBar hK0 : “sin2f1”= 0.30 0.14 0.02 C = -0.21 0.10 0.02 P. Chang 20

  21. B0wKS B0f0KS Measurements on KSp0, wKS and f0KS B0KSp0 Nsig = 344 ± 30 Nsig = 68 ± 13 Nsig = 145 ± 16 Belle update, 386 M BB pairs P. Chang 21

  22. Summary of b → s penguin results Need super B factory to provide enough statistics. 2.6s deviation P. Chang 22

  23. +Loops (penguins) f2/a extraction in B →rr •  measure eff • need to bound |eff-| (shift from loops) • different |Penguin/Tree| for different decays P. Chang 23

  24. 2|-eff| Pure tree Isospin analysis Gronau and London A+- = A(B→h+ h-) Why rr is better? A+0 = A(B→h+ h0) h: p or r • pp : Br(B0→p0p0) is sizeable. A00 = A(B→h0h0)  not enough for A00 and Ã00  too large to set limit on d • rr : 1. Br(r+r-) is large. 2. almost fully long. polarized 3. small non-resonant contr. 4.Br(r0 r0) is small.  The best way to extract f2(a) P. Chang 24

  25. LP2005 Paper-180 hep-ex/050349, accepted by PRL B0 tags B0 tags B0 tags B0 tags Asymmetry Asymmetry Asymmetry Poor tags Good tags CPV on B0→r+r- P. Chang 25

  26. Isospin analysis for B→rr New Use the averages of Belle and BaBar and the r0r0 upper limit from BaBar (a - aeff < 11O). a/f2= 96o± 13o P. Chang 26

  27. Combine pp,rr and rp P. Chang 27

  28. f3 /g Extraction in DK Dalitz color favored color suppressed m-=m(KSp-) m+=m(KSp+) Select D0 → KSp+ p- • B+g[KSp+p-]DK+ • B-g[KSp+p-]DK- P. Chang 28

  29. Distributions of Dalitz Plots P. Chang 29

  30. Results of Dalitz Analysis P. Chang 30

  31. All constraints Angles only No angles Putting it together P. Chang 31

  32. Search for B→tn CKM fit predicts Br(B→tn) = (8.1  2.5) x10-5 Strategy: 1. Use hadronic tag or semi-leptonic tag 2. 1 or 3 prong topology 3. Check EEcl for the remaining event. P. Chang 32

  33. B→K(*) l+l-, Knn • Clean probe for EW scale physics. • Knn measurements: same analysis method as in tn analysis. Belle LP05 New P. Chang 33

  34. B→K(*) l+l- BaBar 227 M (NEW) Belle 275 M +0.075 Br(Kll) = 0.34  0.07 ± 0.03 Br(K*ll) = 0.78  0.12 Br(Kll) = 0.550 ± 0.027 Br(K*ll) = 1.65  0.23  0.10 -0.070 +0.19 -0.17 Probing new physics on AFB of K*ll. Stay tuned for EPS P. Chang 34

  35. Search for B→gg • SM prediction Br(B →gg) ~ 3 x10-8 • Previous measurement: BaBar with 19.7 fb-1: Br < 1.7 x 10-6 • Belle new measurements with 110 M BB: Belle: Br <5.4 x 10-7 @ 90 C.L. P. Chang 35

  36. Helicity Flip Suppressed by ms/mb mixing LP Paper-97 CPV in B → KSp0g Time dependent CPV is suppressed due to the correlation of photon helicity. 386 M Belle-conf-0569 P. Chang 36

  37. hep-ex/0408034 Search for b → d g 1. Exclusive reconstruction 2. Simultaneous fit assuming P. Chang 37

  38. Observation of b → d penguin LP PAPER-155  0.143 < |Vtd/ Vts| <0.260 P. Chang 38

  39. Another Evidence for b →d penguin Belle 275 M BaBar 227 M KSK+ KS KS Preliminary BaBar (10-6) Belle(10-6) Preliminary B→K+K- <0.6 <0.37 +0.53 1.45 0.11 1.0 0.4 0.1 B→K0K+ -0.46 +0.40 0.8 0.3 0.1 1.19 0.13 B→K0K0 -0.35 P. Chang 39

  40. Confirm Direct CP Violation ACP(K+p- ) = -0.133 0.030  0.009 ACP(K+p- ) = -0.113 0.022  0.008 P. Chang 40

  41. Summary of Direct CPV in B→pp 08 WA ACP (K+p-) = -0.115  0.018 ) ~ 3.9 s deviation, why? WA ACP (K+p0) = +0.04  0.04 ACP sum rule (Gronau and Rosner): D(K0p0) -1/2 D(K+p-) + D(K+ p0) = Ọ(e2) Iain Stewart  0.077  0.070 = Ọ(e2 ) P. Chang 41

  42. New Resonance in e+e-→gISR p+p-J/y m = 4260  8 MeV = 88  23 MeV Include y(2S) for cross check Missing mass distribution consistent with g 211 fb-1 P. Chang 42

  43. Summary • Precision measurements becomes a reality. • Deviation of “sin2f1”from b→s penguin is not settled. • Rare decays: sensitive to new physics – sin2f1 /sin2b = 0.6870.032 from b → ccs – f2/a = (99 )o from pp, rr and rp. rr dominates. – D(*)K(*) Dailtz analysis. The best way to extract f3/g. calibration +12 -9 12o <f3/g < 137o (BaBar), 22o < f3/g < 113o (Belle) Central values move closer; propose super B factory. Observe b→d penguin; confirm Direct CPV; many fine measurements. More results will be shown in EPS! P. Chang 44

  44. Backup P. Chang

  45. Current CPV results of B→p+p- Belle 275M ~2.3s difference between Belle and BABAR BABAR 227M P. Chang

  46. P. Chang

More Related