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B  tn and af 2 / gf 3 results from the B factories

B  tn and af 2 / gf 3 results from the B factories. May 20, 2006 Sheldon Stone Symposium @ Syracuse Nobu Katayama (KEK). Outline. Belle B  tn result Belle/BaBar f 2 / f 3 results Super KEKB. Search for B  tn. B  tn is important for both SM and BSM.

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B  tn and af 2 / gf 3 results from the B factories

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  1. Btn and af2/gf3 results from the B factories May 20, 2006 Sheldon Stone Symposium @ Syracuse Nobu Katayama (KEK)

  2. Outline • Belle Btn result • Belle/BaBar f2/f3 results • Super KEKB N. Katayama

  3. Search for Btn • Btn is important for both SM and BSM. • Purely leptonic  Theoretically very clean • More than one n’s  Experimentally very challenging. B factories LEP First Evidence ! April 2006 N. Katayama

  4. Signal Selection (1) N+= 680k eff.= 0.29% purity = 57% • Reconstruct one B in hadronic decay modes • t lepton is identified in the 5 decay modes. • Signal selection criteria • Signal-side efficiency including t decay br. • All selection criteria were optimized before examining the signal region (blind analysis). 81% of all t decay Modes are used 32.92 0.12% N. Katayama

  5. Signal Selection (2) • Extra neutral energy in calorimeter EECL • Most powerful variable for separating signal and background • Total calorimeter energy from the neutral clusters which are not associated with the tag B Minimum energy threshold for single cluster • Barrel : 50 MeV • For(Back)ward endcap : 100(150) MeV Zero or small value of EECL arising only from beam background Higher EECL due to additional neutral clusters MC includes overlay of random trigger data to reproduce beam backgrounds. N. Katayama

  6. Signal validation • Extra neutral energy (EECL) is validated in the doubly tagged sample (control sample); • Btag is fully reconstructed • Bsig is in semileptonic decay modes B+ D(*)0 X+ (fully reconstruction) B- D*0 l-n D0p0 K-p+ K-p+ p-p+ Purity ~ 90% N. Katayama

  7. Background Estimation MC : 94.2  8.0 Data : 96 MC : 89.6  8.0 Data : 93 MC : 41.3  6.2 Data : 43 MC : 18.5  4.1 Data : 21 MC : 23.3  4.7 Data : 21 Sideband Total MC : 267  14 Data : 274 Large MC samples for e+e- BB, qq, Xuln, Xu tn,t+ t- , and rare B decays are used (including beam-background). Majority come from BD(*) X l n (~90%) + Xu l n/rare (~10%). N. Katayama

  8. Result: Opening the Box ! • The signal regions are examined after finalizing all of the selection criteria. 414 fb-1 # estimated background and observed events in the signal region Observe excess in signal region ! N. Katayama

  9. Fit Results • The final results are deduced by unbinned likelihood fit to the obtained EECL distributions. Signal + background S : Significance with systematics Btn Signal Background +6.7 - 5.7 Observe 21.2 events with a significance of 4.2s Signal shape : Gauss + exponential Background shape : second-order polynomial N. Katayama

  10. Btn Branching Fraction Extracted branching fraction for each t decay mode • Branching fractions are calculated by • All t decay modes combined SM : B(Btn)=(1.59  0.40)×10-4 Result is consistent with SM prediction within error N. Katayama

  11. fB|Vub|, fB Extraction • Product of B meson decay constant fB and CKM matrix element |Vub| • Using |Vub| = (4.39  0.33)×10-3 from HFAG 11% = 8%(exp.) + 8%(Vub) 14% fB = 0.216  0.022 GeV [HPQCD, Phys. Rev. Lett. 95, 212001 (2005) ]

  12. Belle/BaBara/f2 and g/f3 results

  13. g/f3: from B+ D0K+ decay Need to use the decay whereVubcontribution interferes with another weak vertex. B– D0K–:B– D0K–: If D0 and D0decay into the same final state, Relative phase:(B– DK–), (B+ DK+) includesweak (φ3) and strong (δ) phase. Amplitude ratio: N. Katayama

  14. GLW method M. Gronau and D. London, PLB 253, 483 (1991); M. Gronau and D. Wyler, PLB 265, 172 (1991) СР eigenstateofD-meson is used (DCP). CP-even : D1K+K–, π+ π– CP-odd : D2 KS π0, KS ω, KS φ, KSη… СР-asymmetry: forD1  A1,2of different signs forD2 Additional constraint: 4 equations (3 independent), 3 unknowns N. Katayama

  15. GLW method BaBar results (211 fb-1) hep-ex/0512067, hep-ex/0507002 A R 0.90±0.12±0.04 0.35 ±0.13±0.04 B DCP+K B DCP-K 0.86±0.10±0.05 -0.06±0.13±0.03 Belle results (253 fb-1) hep-ex/0601032 New R A B+ D1K+ B- D1K- B D1K 1.13 ±0.16±0.05 0.06±0.14±0.05 B D2K 1.17±0.14±0.14 -0.12±0.14±0.05 B+ D2K+ B- D2K- B D*1K 1.41±0.25±0.06 -0.20±0.22±0.04 B D*2K 1.15±0.31±0.12 0.13±0.30±0.08 N. Katayama

  16. B–D0K–- color allowed D0K+π– - doublyCabibbo-suppressed B–D0K–- color suppressed D0K+π– - Cabibbo-allowed Interfering amplitudes are comparable  ADS method D. Atwood, I. Dunietz and A. Soni, PRL 78, 3357 (1997); PRD 63, 036005 (2001) Enhancement of СР-violationdue to use ofCabibbo-suppressedD decays N. Katayama

  17. ADS method Suppressed channel not visible yet: Belle results (350 fb-1) hep-ex/0508048 UsingrD=0.060±0.003, for maximum mixing (φ3=0, δ=180°): rB<0.18 (90% CL) BaBar results (211 fb-1) hep-ex/0504047, hep-ex/0508048 rB<0.23 (90% CL) for BDK rB<0.16 for BD*K N. Katayama

  18. Dalitz analysis method A.Bondar, Proceedings of the Belle Workshop, September (2002) A.Giri, Yu. Grossman, A. Soffer, J. Zupan, PRD 68, 054018 (2003) Using 3-bodyfinalstate, identical for D0and D0: Ksπ+π-. Dalitz distribution density: (assuming СР-conservationin D0 decays) is determined fromD*– D0π–, D0 Ksπ+π– decay  model uncertainty of the result Parameters are obtained from the fit to Dalitz distributionsof DKsπ+π–fromB±DK±decays N. Katayama

  19. M (GeV 2 ) Ksπ – 2 D0 Ksπ+π–decay model Doubly Cabibbo suppressed K* ρ-ω interference N. Katayama

  20. Dalitz analysis (BaBar) BaBar results (211 fb-1) hep-ex/0504039, hep-ex/0507101 BD*K BDK* BDK Model uncertainty from ππ s-wave estimated with K-matrix formalism: 3°. Nonresonant contribution to BDK*is treated by introducing additional free parameter 0<κ<1accounting for BDKSπ contribution. Combined for 3 modes: γ=672813(syst)11(model)° N. Katayama

  21. Dalitz analysis (Belle) Belle result (350 fb-1) New BD*K BDK* BDK 81±8 events 54±8 events 331±17 events B- B+ B- B- B+ B+ N. Katayama

  22. Dalitz analysis (Belle) BDK BDK* BD*K φ3=86+37-93°(stat) φ3=11+23-57°(stat) φ3=66+19-20°(stat) New Combined for 3 modes:φ3=53+15-183(syst)9(model)° 8°<φ3<111° (2σ interval) rDK=0.159+0.054-0.050 0.012(syst)0.049(model)° CPV significance: 78% rDK=0.175+0.108-0.099 0.013(syst)0.049(model)° rDK=0.564+0.216-0.155 0.041(syst)0.084(model)° N. Katayama

  23. α/φ2 : Bρρ B0r+r–has 3 polarization states with different CP eigenvalues Fortunately, longitudinal polarization dominates, therefore, pure CP-even state Belle # of Events BaBar (PRL 95, 041805, (2005)): Belle (hep-ex/0601024): cosq New No significant 00 signal  small penguin contribution BaBar (PRL, 94, 131801 (2005)): N. Katayama

  24. PRL, 95, 151803 (2005) Bρρ BaBar results (211 fb-1) α=100°±13° 79°< α <123° φ2=8 8°±17° 59°< φ2<115° N. Katayama

  25. Signal MC +– 00 2.9  –+ Bρπ(BaBar) BaBar results (192 fb-1) hep-ex/0408099 Time dependent Dalitz analysis assuming Isospin symmetry: Interference between the  resonances gives information on strong phases between resonances can be constrained without ambiguity CP asymmetries:  = (113 +27−17 ± 6)º N. Katayama

  26. a/f2combined add new Belle r+r: B, S, A and new Babar r+ro : B, fL, A Note: Isospin triangle rr does not close • experimental error ? f2 = 97  5 deg. N. Katayama

  27. Angle Summary f2, f3: Remarkable progresses have recently been made but they are still statistically limited f1 = (23  1)º f2 = (97  5)º f3 = (60 )º +5 -4 Consistent with f1+ f2+ f3= 180o SM constraints N. Katayama

  28. Super KEKB • Asymmetric energy e+e- collider at ECM=m((4S)) to berealized by upgrading the existing KEKB collider. • Super-high luminosity  81035/cm2/sec 1010 9 BB per yr.  810 9t +t - per yr. Belle with improved rate immunity Higher beam current, more RF, smaller by* and crab crossing  L = 81035/cm2/sec http://belle.kek.jp/superb/loi N. Katayama

  29. More questionsin flavor physics • Are there New Physics phases and new sources of CP violation beyond the SM ? • Compare CPV angles from tree and loops. • Are there new flavor-changing interactions with b, c or t? • bsnnbar, D-Dbar mixing+CPV+rare, tmg • Are there right-handed currents ? • bsg CPV, BV V triple-product asymmetries f b s Can we answer such questions at a Super B Factory? B _ d _ s s Ks _ d N. Katayama

  30. Why∫L dt = 50ab-1 is a goal? • Most of the interesting measurements will be limited by unavoidable systematics when we reach 50ab-1. Obs. dstat with 50ab-1 dsyst with 50ab-1 Theory err. sin2f1 0.004 0.014 ~0.01 f2 1.2º a few º f3 1.2º O(1) º |Vub| 1% ~1% ~5 % SfKs 0.023 0.020 AfKs 0.016 0.018 Sh’Ks 0.013 0.020 Ah’Ks 0.009 0.017 DCPV in b→sg 0.003 0.002 0.003 N. Katayama

  31. Proposed schedule • Takes 250 years with present KEKB • 8.2 years with Lpeak=4×1035 :Super KEKBbaseline design • 3.3 years with Lpeak=1×1036 10 SuperKEKB ~4-8×1035 Lpeak~1.6×1034 1.6 - 3×1034 8 6 5-10BBB and t+t- every year Integrated luminosity (ab-1) 2 yr shutdown for upgrade 4 Crab cavity installation Belle is here. 0.58ab-1 2 0 2000 2002 2004 2006 2008 2010 2012 2014 Calendar year N. Katayama

  32. Comparison with LHCb LHCb is advantageous in… e+e-is advantageous in… CPV inB→fKS, h’KS,… CPV inB→J/yKS CPV inB→KSp0g Most of B decays not including n or g B→Knn, tn, D(*)tn Time dependent measurements of BS Inclusive b→smm, see t→mg and other LFV B(S,d)→mm D0D0mixing BCand bottomed baryons They are complementary to each other !! N. Katayama

  33. How to achieve the super-high luminosity Crab cavity N. Katayama

  34. New parameter set for 81035 N. Katayama

  35. What’ new in the param. set? • 81035 cm-2s-1 is achievable with the same beam currents, beta and bunch lengths as before (4 1035 cm-2s-1) • The beam-beam simulation was improved by using more longitudinal slices to reduce numerical noises and instabilities on a new super computer at KEK • A new choice of emittance (ratio or horizontal emittance) • Crab crossing (head on collision) is necessary • Crab waist, traveling focus may help lifetimes but not essential at this moment N. Katayama

  36. Accelerator R&D • Vacuum components for higher current • Antechambers, coating, bellows, collimetors,, • Superconducting quadrupoles • High power RF components • Bunch-by-bunch feedback system • C-band linac • Beam diagnostics • Crab cavities N. Katayama

  37. Components to be upgraded Interaction Region Crab crossing q=30mrad. by*=3mm New QCS New Beam pipe More RF power Damping ring Linac upgrade N. Katayama

  38. Crab cavity: a new idea for higher luminosity • Head-on collisions with finite crossing angle ! • avoid parasitic collisions • collisions with highest symmetry  large beam-beam parameter N. Katayama

  39. Now even more with better simulation! We are here • First performance report expected in fall 2006 • Factor ~2 gain in Lpeak may be expected within ~2 yrs • ~31034cm-2s-1 within our reach fall N. Katayama

  40. Super KEKB components Bellows Antechamber MO-flange C-band RF cavity N. Katayama

  41. N. Katayama

  42. Requirements for the detector Issues 10~20 times more backgrounds N. Katayama

  43. Super Belle Faster calorimeter with Wave sampling and pure CsI crystal Super particle identifier with precise Cherenkov device KL/m detection with scintillator and new generation photon sensors Background tolerant super small cell tracking detector New Dead time free readout and high speed computing systems Si vertex detector with high background tolerance N. Katayama

  44. Summary of Super KEKB upgrade • Why? – Search for new sources of flavor mixing and CP violation • How? – Increase NB, decrease by*, and crab crossing: L=81035/cm2/s • New beam pipe, crab cavity, new injector with damping ring • Belle will also be upgraded • Ideas for even higher luminosity and better detector are desperately needed • Please join and help! N. Katayama

  45. Systematic Uncertainty • Signal selection efficiencies • Tag reconstruction efficiency : 10.5% Difference of yields between data and MC in the B- D*0l-ncontrol sample • Number of BB : 1% • Signal yield : • signal shape ambiguity estimated by varying the signal PDF parameters • BG shape : changing PDF • Total systematic uncertainty +12% -10% +17% -15% N. Katayama

  46. Dalitz analysis: sensitivity to the phase N. Katayama

  47. Model-independent approach A.Bondar, A.Poluektov hep-ph/0510246 A.Giri, Yu. Grossman, A. Soffer, J. Zupan, PRD 68, 054018 (2003) 50 ab-1 at SuperB factory should be enough for model-independent γ/φ3 Measurement with accuracy below 2° ~10 fb-1 at ψ(3770) needed to accompany this measurement. N. Katayama

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