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B Factories: Status and Prospects

B Factories: Status and Prospects. CKM: Cabibbo-Kobayashi-Maskawa CPV: CP Violation. Masashi Hazumi (KEK). March 28, 2007 Flavor in the era of the LHC CERN.

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B Factories: Status and Prospects

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  1. B Factories: Status and Prospects CKM: Cabibbo-Kobayashi-Maskawa CPV: CP Violation Masashi Hazumi (KEK) March 28, 2007 Flavor in the era of the LHC CERN

  2. It seems all the important results from B factories have already been shown and discussed at this workshop in the last two days. What should I talk about ? CKM: Cabibbo-Kobayashi-Maskawa CPV: CP Violation Masashi Hazumi (KEK) March 28, 2007 Flavor in the era of the LHC CERN

  3. Outline • Introduction • CPV and CKM • New physics searches • Future prospects All introductory slides are put in the backup part.

  4. Integrated luminosity 1100/fb !! KEKB + PEP-II ~ 1 Billion BB pairs ~710/fb (Jan 07) Triumph in accelerator science ! KEKB for Belle ~400/fb design luminosity PEP-II for BaBar

  5. Achievements at B factories Evidence for D0 mixing Observation of direct CP violation in B gp+p- Exciting results every year ! Evidence for B gtn Observation of b g dg Evidence for direct CPV in B g K+p- Discovery of X(3872) Hint at new physics: CPV in B gfKs Observation of B g K(*)ll Observation of CPV in B meson system

  6. CPV and CKM

  7. Discovery of CPV in the B meson system (2001) by BaBar and Belle sin2b history (1998-2005)

  8. Mar. 2007 sin2f1 = 0.6780.025 (4% accuracy) World avg. (i.e. with OPAL, ALEPH,CDF) (f1 = 21.3  1.0 deg.) Average with B factories only hep-ex/0703021 PRL 98, 031802 (2007) • B0g J/K0, • (2S)KS, • hcKS, • c1KS, • J/K*0 B0g J/K0

  9. Direct CPV in B0g J/ K0 C = 0.049 ± 0.022 ± 0.017 with all charmonium modes combined C(J/K0)

  10. Systematic uncertainties sin2b C Uncertainties from vertex reconstruction ~ 0.01 OK for present B factories, key for more precise measurements at Super B

  11. b g s tCPV: One of the best new physics probes SUSY as an example Method: Compare S(fK0) with S(J/yK0) SM prediction: DS S(fK0)-S(J/yK0)  0 New CP-violating phase can enter O(1) effect allowed even if SUSY scale is above 2TeV.

  12. Smaller than bgccs in all of 9 modes Theory tends to predict positive shifts (originating from phase in Vts) Mar. 2007: f1 with bgs Penguins Naïve average of all b g s modes sin2beff = 0.53 ± 0.05 2.6 s deviation between penguin and tree (b g s) (b g c) More statistics crucial for mode-by-mode studies

  13. BgffK: ultra-clean mode M. Hazumi, PLB583, 285 (2004) • Interference between B ghc(gff)K and 3-body b g s process • CP violation in the SM ~0, can be ~0.4 if new physics enters b g s • Ultra-clean mode to reconstruct, almost no background Belle observation (hep-ex/0609016) CP asymmetry in hc region:

  14. B0g D+D- hep-ex/0702031 not confirmed by BaBar Evidence for large CPV from Belle  Need more data b g ccd another place to study f1

  15. B0 tag f2 (a): B0p +p - hep-ex/0703016 hep-ex/0608035 300 B0 tag 200 Num. of Ev. Num. of Ev. 100 0 +1 Asym. 0 Asym. -1 -5 0 5 Dt (ps) Dt (ps) BaBar 383MBB Belle 535MBB App = +0.55  0.08  0.05 Spp = -0.61  0.10  0.04 Cpp (-App) = -0.21  0.09  0.02 Spp = -0.60  0.11  0.03 Direct CPV @ 5.5s CPV @ 5.5s

  16. f2 (a): B0pp Constraint on f2 Cpp 2.1s Consistency: 2.Xs f2 (deg.) * 1-CL ~ 0 for f2 = 0 f2 = 92+12-10 Spp

  17. f2 (a): B0r 0r 0 hep-ex/0612021 BaBar 384MBB 3.5s

  18. f2 (a): B0rr Brr is not the best mode anymore Constraint on f2 Before 2006 Summer A00 A+-/2 A0+ 2(f2eff – f2) Triangles were squashed With New B.F. of Br0r0, r+r0 f2 (deg.) For further improvement, we need ACP of B0r0r0. f2 = 92  21 deg.

  19. f2 (a): B0(rp)0 Dalitz Analysis hep-ex/0701015 hep-ex/0703008 f2 (deg.) Dalitz + Pentagon Analysis f2 (deg.) Belle 449MBB BaBar 375MBB 68 < f2 < 95 with other allowed regions

  20. +5 -19 aGlobal Fit = [ 98 ] º a/f2 = [93 ] +11 - 9 DPF/JPS2006: BaBar(pp/rp/rr) + Belle(pp/rr) consistent with a global fit w/o a/f2 Bgrp to be included • Solution around 0/180deg. is eliminated if • Br(Bs g K+K-) + SU(3) is used for pp. (see talk by M.Ciuchini)

  21. s u c s V*ub + d + d B B l3 D0 fCOM c K+ b b W W u Vus Vcs K+ _ V*cb u u fCOM D0 l3 u u Direct CP violation and f3 (g) VtdV*tb f2 VudV*ub f3 B g D(*)K(*) f1 VcdV*cb Color suppressed Color allowed Choice of fCOM very important !

  22. g/f3 = [62 ] +38 -24 f3 Summary fCOM Improvements with more statistics expected in the near future

  23. HQE (Heavy Quark Expansion) Vub Vud Decay rate with expansion in series of 1/mb, non-perturbative parameters extracted from shape information Vus THEORY METHOD Inclusive semileptonic B decays: B g Xcln Vcs Vcb Vcd Vtb 3 independent parameters EXPERIMENT • El: lepton energy • q2: lepton-neutrino mass squared • Mx: hadronic mass Vtd Vts

  24. Vub Vud 1% accuracy** Vus Inclusive semileptonic B decays: B g Xcln RESULTS Vcs Vcb Inputs: decay rates and moments (shape) from BaBar, Belle, CDF, CLEO, DELPHI Vcd Vtb B g Xsg Eg spectrum also used as an input Vtd Vts ** B g D(*)ln (exclusive) with LQCD  ~4% accuracy

  25. |Vub| = (4.490.190.27)x10-3 ~7% accuracy** Vub Vud Vus Method Inclusive semileptonic B decays: B g Xuln Vcs Vcb Vcd large bgc background EXPERIMENT Vtb • theory uncertainties (shape function) • several different schemes Vtd Vts ** B gpln (exclusive) with LQCD  ~12% accuracy

  26. Vub Vud Vus Vcs Vcb Vcd Vtb Vtd Vts Summary of |Vcb|, |Vub| *P. Urquijo, CKM2006 other numbers from C. Schwanda, Lathuile2007

  27. Vub Vud Vus Cannot be measured from top semileptonic decays ... Loop diagrams METHOD1 Vcs Vcb Vcd Light Cone Sum Rules Belle BaBar+Belle(10-6) Vtb Inclusive BF(B g Xsg) for Eg>1.6GeV  |Vts| with ~7% accuracy Mbc(GeV/c2) B Vtd Vts Vts s,d Caveat: This assumes the unitarity.

  28. Vub Vud Vus METHOD2 Box diagrams Vcs Vcb LQCD Vcd (Okamoto, hep-lat/0510113) CDF ~0.7% accuracy Limits precision on |Vtd|, |Vts| to ~ 10% BaBar+Belle ~1% accuracy Vtb Vtd Vts |Vtd| = (7.4  0.8) x 10-3 BaBar (PDG2006)

  29. Vub Vud Vus Box diagrams METHOD2 Vcs Vcb Vcd (~4% accuracy) Vtb Vtd Vts CDF (2006)

  30. CKM Global Fit Good overall agreement. O(1) new physics unlikely. Need to be able to detect O(0.1) effects as the next step. Kobayashi-Maskawa model of CP violation has been firmly established, just like Newtonian mechanics was established.

  31. Comment on |Vub| tension (1) M. Neubert Moriond EW 2007

  32. T. Iijima Comment on |Vub| tension (2) -3 |Vub| [x10 ] |Vub| from CKM fit (direct meas. not included) -3 -4 Br(tn) [x10 ] |Vub| from SL SM formula w/ f B = 0.216 +/- 0.022 GeV Br(Bgtn) |Vub|2 Belle result Br=(1.79 +0.72 -0.71 )x10 -4 Improved Br(B gtn) meas. important to disentangle possible origins of the “Vub tension”

  33. Direct CPV in B0g K+p- (established in 2004) hep-ex/0608049 • Direct CPV already observed in K decays. Important to see it in B decays ?  Yes ! There are well-motivated “B-superweak” models. • e.g. Superstring-inspired “B-superweak” model that also allows SUSY EW baryogenesis [M. Brhlik et al., PRL 84, 3041 (2000)]. (5.5 s) K+π-: -0.093±0.018±0.008 (4.7σ) hep-ex/0703016

  34. ACP(Kp) puzzle ? ACP(K+p0) = +0.047  0.026 ACP(K+p-) = -0.093  0.015 deviation: 0.14/0.03 > 4.6s New physics ?

  35. ACP(Kp) puzzle ? • Naive expectation, ACP(K+p0) ~ ACP(K+p-), is too crude and is not adequate for new physics search. • Large color-suppressed tree may exist. • “Sum rule” offers more precise tests.   D. Atwood, A. Soni, PRD58 (1998) 036005 M. Gronau, PLB627 (2005) 82 A(K0p0) = -0.160.04 (from sum rule) A(K0p0) = -0.120.11 (tCPV meas.) (as of Aug.2006)

  36. Summary of CPV and CKM • Kobayashi-Maskawa model of CP violation has been established, just like Newtonian mechanics was established. • Yet there are several inconsistencies that are uncomfortable for the Standard Model. • b g s tCPV (2.6s) • Vub tension (2.9s if you think b g s tCPV anomaly is a statistical fluctuation and use combined sin2f1) • Only more data will tell us the truth. At the same time, theoretical improvements are also important.

  37. New physics searches

  38. B  Decays w/ “Missing E(>1n)” SM : B decay constant Lattice QCD BSM : sensitive to New Physics from H W. S. Hou, PRD48, 2342 (1993)

  39. Full Reconstruction Method • Fully reconstruct one of the B’s to tag • B production • B flavor/charge • B momentum Equivalent to “single B meson beam” ! Decays of interests BXu l n, BK n n BDtn, tn B e- (8GeV) e+(3.5GeV) Υ(4S) p full (0.1~0.3%) reconstruction BDp etc. B Powerful tools for B decays w/ neutrinos

  40. B gtn results Belle BaBar PRL97, 251802 (2006). hep-ex/0608019 Belle Hadronic tag D l n tag e+nn (3.6%) m+nn (2.4%) p+n (4.9%)p+p0n(2.0%) pppn (0.8%) t+  e+nn (eff: 4.1%), m+nn (2.4%), p+n (4.9%), p+p0n (1.2%) No clear signal First evidence, 3.5 s

  41. Constraints on H mass Use known fB and |Vub |Ratio to the SM BF. W. S. Hou, PRD48, 2342 (1993) excluded rH=1.130.51 excluded 449M

  42. Other searches with B decays AFB(B g K*ll) • Br(b g sg): best NP killer so far • B0g Ksp0g tCPV Extreme NP scenarios are already excluded.

  43. Tau LFV summary J. Yi, Moriond QCD 2007

  44. tgmg 535/fb • Dominant background: tmnn + ISR (90%) • Small contamination of mm BG in DE>0

  45. (Near) future prospect PDG2006 Belle Babar • Possible sensitivity at 5ab-1 based on eff. and NBG of most sensitive analysis Estimated upper limit range of Br

  46. Evidence for D0 mixing hep-ex/0703020 384/fb K. Flood at Moriond EW 2007 * No CPV is seen

  47. Evidence for D0 mixing hep-ex/0703036 Belle Preliminary Presented at Moriond EW 540/fb (* No CP violation seen)

  48. Prediction is disfavored data Fit BG Prediction Br(Y(1S)invisble)=0.6% Search for light dark matter on Upsilon(3S) PRL 98, 132001 (2007) Y(3S) runs : 2.9 fb-1 (Feb, 2006 : 4days)  better sensitivity than ~7year Y(4S) data Y(3S) g Y(1S)p+p- Br(Y(1S)invisible) < 2.5x10-3 (90%C.L.) B. McElrath, PRD 72, 103508 (2005) Nsignal = 38 ± 39 Y(1S)  DM DM

  49. Future prospects

  50. Efforts for improvements never stop !  Oide’s talk • ~2/ab from BaBar+Belle by the end of 2008 • BaBar will end in 2008 • Belle proposing a major upgrade (= SuperKEKB) • part of the “Japanese HEP master plan” • luminosity goal : 8 x 1035/cm2/s (peak), 50/ab (integrated) Cosmic-ray m in newly-installed BaBar LST sextants (Nov.06)  better m detection efficiency Crab cavities installed (Jan.07)  luminosity goal = 3 x 1034/cm2/s

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