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Recent results from B factories

Recent results from B factories. A. Oyanguren IFIC, UV-CSIC. III Jornadas CPAN, Barcelona 2 nd – 4 th Nov. 2011. Outline.  B factories (Belle & BaBar ).  Leptonic decays : B, D s    .  Semileptonic decays : BD*, V ub , charm.  CPV (B, c and  decays ) .

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Recent results from B factories

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  1. Recent results from B factories A. Oyanguren IFIC, UV-CSIC III Jornadas CPAN, Barcelona 2nd – 4th Nov. 2011

  2. Outline • B factories (Belle & BaBar) • Leptonicdecays: B, Ds • Semileptonicdecays: BD*, Vub, charm • CPV (B, c and  decays) • Raredecays: Bs, BK, B, B, D, Xch • Plans at SuperFlavourFactories (Belle II & SuperB) III Jornadas CPAN, Barcelona 2 A. Oyanguren

  3. B e+ e- z~ c  B ~ 200m B B factories KEKB √s=10.58 GeV Υ(4s) Υ(4s) BaBarp(e-)=9 GeV p(e+)=3.1 GeV=0.56 Bellep(e-)=8 GeV p(e+)=3.5 GeV =0.42 III Jornadas CPAN, Barcelona 3 A. Oyanguren

  4. B factories In addition to (4S)also large samples of other (nS) decays! # of produced (nS) Fantastic performance far beyond design values! III Jornadas CPAN, Barcelona 4 A. Oyanguren

  5. Leptonic decays Motivation: • Weakannihilationprocesses (helicitysuppressed) • sensitiveto New Physicseffects • B   : a chargedHiggscouldenhancethe SM • branchingfraction: Fromsemileptonicdecays: by: |Vub|=(3.89 ± 0.44) x 10-3 [PDG 2010] FromLattice QCD calculations: fB = 191 ± 3 ± 13 MeV [Lenz et al., PRD 83, 036004 (2011)] 0 = radiative correction ~1%) III Jornadas CPAN, Barcelona 5 A. Oyanguren

  6. Leptonic decays Experimental method: Reconstruct one B meson in hadronic BD(*)X or B   J/X decays (tag ~1%) Look for signal in the recoil: using kinematical and event shape information  Look for extra energy Eextra = sum of neutral clusters in the ECM calorimeter  Study Extra using double tag events to control the bkg.  Extract B from unbinned max. likelihhod fit To Eextra: 426 fb-1 3.3 significance BaBar combined: Belle: III Jornadas CPAN, Barcelona 6 A. Oyanguren

  7. Leptonic decays Final measurement of sin2 sin2 from CP measurements in B0→ cc K0 Belle, preliminary, 710 fb-1 Tension between B(B→) and sin2 (~2.5) remains III Jornadas CPAN, Barcelona 7 A. Oyanguren

  8. Leptonic decays Ds   can alsobeenhancedby a chargedHiggsorleptoquarks: fDscalculatedby LQCD withsmall error fDs= (248.6 ± 2.5) MeV  At BaBarDs  e, , measuredfromfully reconstructedeventsusingtherecoilmass and theEextra BaBar Agreementwiththeory 521fb-1 [PRD RC 82, 091103 (2010)] III Jornadas CPAN, Barcelona 8 A. Oyanguren

  9. Semileptonic: B  D(*) Motivation: • Sensitivetocharged-Higgseffects • Involveformfactorswhich can bemeasured in BD(*)e/ decays • Observables: R(D) and R(D*) ratios • - can beenhancedbythecharged-Higgs (tan/mH) • - severalsyst. and theo. uncertainties cancel out SM predictions: R(D) = 0.31  0.02 R(D*) = 0.25  0.02 [Nierste, Trine, Westhoff PRD78 (08) 015066] III Jornadas CPAN, Barcelona 9 A. Oyanguren

  10. Semileptonic: B  D(*) •  • ee Experimental method: • BaBar: Btagfullyreconstructedintohadrons (Improvedefficiencies (lepton and Btag)) • Bsig: D(*) and lepton (, e) • - 4 signalsamples: (D0, D+, D*0, D*+) • (toextract BD(*)) mmiss2 = (pe+e- -pBtag-pD(*)-p)2 426 fb-1 • - 4 control samples: (D0, D+, D*0, D*+)0 • (to derive D** bkg) • 2D unbinned ML fit mmiss2-p*(3x4 par.) • Yieldsfor: • B (D0, D+, D*0, D*+) • B (D0, D+, D*0, D*+) • B (D0, D+, D*0, D*+)0 R(D) and R(D*) Largesignalsignificance (>5) forallchannels III Jornadas CPAN, Barcelona 10 A. Oyanguren

  11. Semileptonic: B  D(*) SM predictions: R(D) = 0.31  0.02 R(D*) = 0.25  0.02 Results (preliminary): R(D) = 0.456  0.053  0.056 R(D*)= 0.325  0.023  0.027 SM 1.8 largerthan SM prediction  favorslarge tan Comparisonwithpreviousresults: (w/o 2011) (w/o 2011) III Jornadas CPAN, Barcelona 11 A. Oyanguren

  12. Semileptonic: Vub Motivation: • Charmlesssemileptonicdecaysallowusto • measureVub(upper UT vertex) • Challenge: suppresscharmbackground BX = BXc + BXu (50 : 1) BX BXu • Twodifferent experimental methods: • - Inclusive:highstat. butmuchbkg: use kinematiccuts: • Theory:Shapefunctionfrom QCD • - Exclusive:final meson (,,…): lowstat. butbetterbkgrejection. • Theory: Formfactorsfrom QCD El, q2, MX and P+ = EX -|pX| III Jornadas CPAN, Barcelona 12 A. Oyanguren

  13. Semileptonic: B  Xu Signal side Experimental Method: Tagside • At BaBar, Btagfullyreconstructedhadronically • ( ~0.3-0.5%) +  or e fromtheBsig (4S) • Xufromallremainingtracks and neutral clusters •  estimatedfrommissing E and p • Bkgsupression: • 426 fb-1 • - CombinatorialsubtractedfrommES • - Charm: B  D* partialreconstructed • kaon veto, only 1leptonp* > 1 GeV • Several PS regions, 2D fitfor B(BXu)/B(BX ) in q2-Mx for p* > 1GeV BaBar - K+  BXc bkg and BXu signalyields B(BXu)=1.80 (13) (15) x 10-4 lepton D0 B0 - Vubextraction: B0 Average: BNLP: [Bosch et al. , PRD 72 (05) 073006]  + DGE: [Andersen et al. , JHEP 0601 (06) 097] |Vub|= (4.31 0.25exp  0.16theo )10-3 GGOU: [Gambino et al., JHEP 0710 (07) 058] Xu [tobesubmittedto PRD] ADFR: [Aglietti et al., EPJ. C 59 (09) 831] III Jornadas CPAN, Barcelona 13 A. Oyanguren

  14. Semileptonic: B   • The exclusive B semileptonicdecayrateisdescribed as function of formfactors: = p, h, h’, r, w • QCD calculations: Lattice data III Jornadas CPAN, Barcelona 14 A. Oyanguren

  15. Semileptonic: B   PRD 83 (2011) 032007 • BaBar, untaggedanalyses PRD 83 (2011) 052011 Loose  reconstructionfromfull event FittoBaBar + Belle + LQCD Backgroundsuppressionbycutsor Neural Net  FitusingE= (PBPbeams-– s /2)/2 , mES= [(s/2 + pBpbeams- )2 /E2beams - p2B] and q2= (p + p)2 = (pB- p)2 (in 12 or 6 bins) B(Be)=1.42 (5) (7) x 10-4 BaBar: B (Be) =1.41 (5) (7) x 10-4 |Vub| = (3.19 ± 0.14 ± 0.27) x10-3 Belle: B (Be) =1.49 (4) (7) x 10-4 • (V. Luth, J. Dingfelder) [arXiv:1012:0090] III Jornadas CPAN, Barcelona 15 A. Oyanguren

  16. Semileptonic: Vub • Exclusive: |Vub| = (3.19 ± 0.14 ± 0.27) x 10-3 • (V. Luth, J. Dingfelder) • Inclusive: |Vub| = (4.34 ± 0.13 ± 0.15) x 10-3 (V. Luth, [NS61CH06-Luth]) Inclusive |Vub| Exclusive |Vub| >2 differencesincemanyyearsago and Vub from B  largerthan forB  New Physicscontribution? (RH currentsmodification) III Jornadas CPAN, Barcelona A. Oyanguren

  17. Semileptonic: charm • Charmsemileptonicdecaysallowtomeasureformfactors in thecharm sector, validating LQCD methods •  increasetheoryprecisioninvolving B decays •  trust LQCD calculationsensuringpossible New Physicssigns Example: the leptonicconstantfDs: >3 !?! fDspuzzle: exp theo contribution from a chargedHiggs? Kronfeldplot, N. Simone: FERMILAB-CONF-10-594-T • Severalcharmsemileptonicchannelshavebeenstudied at BaBarfrome+e-  cc • using a partialreconstructiontechnique: DKe , DsKKe,D+Ke published De (soon)  can berelatedto Be  accesstoVub III Jornadas CPAN, Barcelona 17 A. Oyanguren

  18. Semileptonic: charm • Quite precise form factor measurementsfromBaBar need LQCD improvements [PRD 78, 051101(R) (2008)] [PRD 76, 052005 (2007)] BaBar BaBar 214 fb-1 fK+(q2) BaBar 75 fb-1 Dsen Dsen D0K-e+n [PRD 83, 072001 (2011)] BaBar Experiments BaBar D+K*e+n BaBar 348 fb-1 D+K*e+n D+K*e+n A1(q2), A2(q2), V(q2) r2=A2(0)/A1(0) • rv=V(0)/A1(0) III Jornadas CPAN, Barcelona 18 A. Oyanguren

  19. CP Violation The CKM matrix Motivation: • • CP violation discovered ~50 years ago • observing the decay KL → π+π- • • In the SM CPV arises from the not vanishing • phase of the CKM matrix • • New Physics can induce additional FCNC • and CP-violating phases • • Many observations of CPV processes in the • last decade in the beauty and strange sectors •  Global consistency with SM predictions • • No observation yet of CPV effects in the • charm sector • • No observation yet of CPV effects in the • lepton sector 19 A. Oyanguren III Jornadas CPAN, Barcelona

  20. CP Violation in D decays Motivation:  Direct CP violation in D decays arises through interference between: Vcs  In the SM is CKM suppressed O(10-3) or less:  New Physics can increase or reduce the effect: - e.g. additional CP phase from charged Higgs boson  SCS decays are more likely to show the effect if present [PRD 75, 036008 (2007)] [hep-ph/0104008 (2001)]  Current experimental sensitivity O(10-3) [PRD 51, 003478 (1995)] 20 A. Oyanguren III Jornadas CPAN, Barcelona

  21. CP Violation in D decays Experimental method:  Due to CPV in mixing in the kaon sector, the direct CP asymmetry for D+Ks+  At BaBar: signal yields from likelihood fit to m(+K0s), with selection based on a Boosted Decision Tree with 7 variables:  807K D±signal events  Measure • is expected to be [hep-ph/0104008 (2001)] Forward-Backward asymmetry Detector charge asymmetry •  Data-driven method to correct for A • Use tracks from e+e-(4S)BB decays (isotropic in rest frame) to map the ratio of +/- detection efficiencies • Offset on ACP  +0.05% 21 A. Oyanguren III Jornadas CPAN, Barcelona

  22. CP Violation in D decays •  Use data-driven method to extract AFB, and ACP in bins of polar angle D+Ks+ [PRD 83, 071103(R) (2011)] Consistent with SM (-0.332±0.006)%  At Belle D0 KS0, tag D flavour with the D* decay ACP = -0.28  0.19  0.10 [PRL106, 211801 (2011)] 22 A. Oyanguren III Jornadas CPAN, Barcelona

  23. CP Violation in Ks t- nt Motivation:  CP violationnotyetobserved in thelepton sector u W-  A deviation of the measured ACPfrom ACPSM would be a hint of New Physics • e.g. an additional CP violating phase from an exotic charged Higgs boson Can consider --Ks(>=00)since0s are not expected to change the asymmetry p-  Searchfordirect CP violation in tau decays: --Ks d  within the SM, due to the Ks presence, the asymmetry: Tree s d K0 • is expected to be [Bigi and Sanda, PLB 625, 47 (2005)] • (same argument than for DKs decays) [PLB 398, 407 (1997)] 23 A. Oyanguren III Jornadas CPAN, Barcelona

  24. CP Violation in Ks Experimental method:  Reconstruct from continuum --Ks(>=00) (up to 30s) •  Electron and muon tags with p* > 4 GeV • (reduce bkg from non--pairs)  Reconstructed hadronic mass < 1.8 GeV (rejects qqbkg) •  Remaining background further reduced using information of: • qq events: visible energy, number of neutral clusters, thrust, total transverse momentum •  Fake K0s: displaced vertex, invariant mass, momentum and polar angle of the K0s candidate Invariant mass of the hadronic final state (00s) 340k events 24 A. Oyanguren III Jornadas CPAN, Barcelona

  25. CP Violation in Ks Experimental method:  Measured raw ACP value (after subtraction of qq background and non-K0s decays) has to be corrected by: • Different nuclear reaction cross-section of K0 and K0 with material detector • (0.14±0.03)% for e-tag, (0.14±0.02)% for -tag • Errors include uncertainties from kaon-nucleon cross-sections and isospin • Dilution from background modes including K0s  Result: [Preliminary, submittedto PRD-RC arXiv:1109.1527] Systematic uncertainties 3 from the SM prediction 25 A. Oyanguren III Jornadas CPAN, Barcelona

  26. CP Violation in Bc decays Motivation: •  Many such decays are dominated by bs penguins • Tree amplitudes subdominant in SM • Time-dependence and FSI (intermediate states) allow to measure the CKM angles •  New Physics can change CP asymmetries, BRs and polarizations in BVV decays •  Use kinematic constraints from beam energies •  Event shape variables combined into a linear (Fisher) or non linear (NN) combination. Tagging (other “B”) information often used Tree Experimental method: Penguin • Apply selection to reject continuum • asvariable in ML fit 26 A. Oyanguren III Jornadas CPAN, Barcelona

  27. CP Violation in Bc decays  Direct CP violation difference in B K+-and K+0 at Belle DAKp= ACP(Kp0) - ACP (Kp) Update the 2008 result with the full data set and improved reconstruction - ~2x more data preliminary 772 M BB Belle preliminary: AK= +0.112 ± 0.028 @4 27 A. Oyanguren III Jornadas CPAN, Barcelona

  28. CP Violation in Bc decays  Direct CP violation difference in B0 K+-0 and B+K+00at BaBar •  Perform ML fit with mES and NN, and for K+-0 only, also E and Dalitz plot •  For B0K+-0 • BF(B0K+-0) = (38.5 ± 1.0 ± 3.9)10-6 • ACP(K*+-) = -0.29 ± 0.11 ± 0.02 • When combined with B0Ks+- : •  For B+K+00 • First inclusive measurement • Measure resonances • in a two-body fashion • 10  significance 454x106 BB pairs [PRD 83, 112010 (2011)] 3.1 evidence for direct CPV • ACP(K*+-) = -0.24 ± 0.07 ± 0.02 471x106 BB pairs • ACP(K*+0) = -0.06 ± 0.24 ± 0.04 Preliminary 28 A. Oyanguren III Jornadas CPAN, Barcelona

  29. Rare decays •  Rare processes are quite sensitiveto New Physicseffects •  B: Belle:fullyrecotag + nothing in thesignalside BR< 1.3 x 10-4 @ 90% CL (BaBar: BR< 2.2 x 10-4 ) •  BK: BaBar: semileptonictag + K and 2 in • thesignalside[PRD 82, 112002 (2010)]  B(s+d): BaBar: semileptonictag + 1  in the signalside: ACP = 0.056 ± 0.060 ± 0.018 (SM) x10-5  B: BaBar:upper limit (UL) lowered by a factor 2: BR< 3.2 x 10-7 @ 90% CL •  D: BaBar: BR< 2.4 x 10-6 @ 90% CL B: D • Most of LFV and LNV Xchll BF ULs down by 1 order of magnitude (10-6) 29 A. Oyanguren III Jornadas CPAN, Barcelona

  30. Future: SuperB, Belle-II  Two new facilitiesaimingtoanintegratedluminosity of 50-75ab-1around 2020 SuperB, Frascati (Italy) Belle-II, Tsukuba (Japan)  Approved, build a new tunnel, upgrade PEP-II and BaBar, quickly ramping up  Approved, major upgrade at KEK in 2010-14 SuperKEKB+Belle II, construction started Physics: Sensitivity B() ~ 10-9, B()~10-10,B(h)~10-10 CharmPhysics: Precision CP parameters: (K) (~10-5), sensitivity FCNC: D(h) (~10-8) B Physics: Precision BK (~20%), B (~ 4%), B (~ 5%), BD (~ 2%), ACP(bs) (~ 0.002), Vub (~ 2%) 30 A. Oyanguren III Jornadas CPAN, Barcelona

  31. Summary 31 A. Oyanguren III Jornadas CPAN, Barcelona

  32. Summary • B  D(*) Improvedmeasurements at BaBar BD0 and BD+ more than 5 significance • R(D(*)) exceedby 1.8  the SM valuesfavorslarge tan |Vub| excl. = (3.19 ± 0.14 ± 0.27) x 10-3 • Vub |Vub| incl. = (4.34 ± 0.13 ± 0.15) x 10-3 Despitethe experimental and theoreticaleffortsthediscrepancy between exclusive and inclusive measurementsremains: whatdoesitmeans? whatdon’tweunderstand? • CharmSemileptonicformfactors Quite precise resultsfromBaBarforDKe, Ds e, D K*e, formfactorsallowtocheck QCD methods: need LQCD improvements III Jornadas CPAN, Barcelona 32 A. Oyanguren

  33. Introduction B and charmsemileptonicdecays are treelevelprocesses involving CKM matrixelements: VudVusVub VcdVcsVcb VtdVtsVtb 0.00389(44) VCKM= 0.0406(13) PDG10 0.230(11) 1.023(36) New Physicscontributions can onlybeseen: coupling ~ mbmtan2  in semileptonicdecaysinvolving leptons:  B D()  bycomparing CKM matrixelements in leptonicand semileptonicdecays  Vub: Inclusive B Xu , exclusive B  Note: Must control (bymeasuring) QCD effects (formfactors)  Charmsemileptonicdecays III Jornadas CPAN, Barcelona 33 A. Oyanguren

  34. Charm sl decays Analysisprocedure: • Partialreconstructionmethod; e+e-  cc; onlyelectrons • D* tag in case of DKe, no tagforDsor D+decays • Compute the D(s)directionfromalltracks  signaltracks • q2 and angular distributions: kinematicfitwithsignal • tracksmomenta and missingenergyinformation • Backgroundsuppressionusingeventshape and • topological variables • Background control, test of theanalysistechnique and thenormalization are obtainedfromhadronic data samples (ex: DK, D K) III Jornadas CPAN, Barcelona 34 A. Oyanguren

  35. Semileptonic: B  D(*) Fitresults(preliminary): (isospin) (isospin) • largesignalsignificance (> 5) • forallchannels Systematics(preliminary): - Selectioncuts: ~6%(D*),~9%(D) - D** fitted in D(*)0 samples: ~4%(D*), ~5%(D) III Jornadas CPAN, Barcelona 35 A. Oyanguren

  36. B  Xu Summary of Vubmeasurements: |Vub| = (3.19 ± 0.14 ± 0.27) x10-3 • Exclusive: (V. Luth, J. Dingfelder) • Inclusive: |Vub| = (4.34 ± 0.13 ± 0.15) x 10-3 (V. Luth, [NS61CH06-Luth]) III Jornadas CPAN, Barcelona 36 A. Oyanguren

  37. Leptonic decays III Jornadas CPAN, Barcelona 37 A. Oyanguren

  38. Vub exclusive: BaBar combined • Small eventoverlap of B0- (<1%) BaBarcombinedresult: • Uncorrelatedstatisticaluncertainties • Highlycorrelatedsystematics BaBarFitto BGL Lattice LCSR BaBarfitto BGL includingLattice data points (B : LCSR q2 < 12GeV2, LQCD q2 > 16GeV2) (fitsfromJ.Dingfelder and V. Luth) III Jornadas CPAN, Barcelona 38 A. Oyanguren

  39. Vub exclusive: B   PRD 83 (2011) 052011 Analysesprocedure: PRD 83 (2011) 032007 BaBar data samples: 423 fb-1 , 349 fb-1 • Untaggedanalyses (highstat., more bkg.), e +  Loose  reconstructionfrom full event(p = pbeams- pi) Backgroundsuppressionbycutsor NN  2D or 3D fit E = (PBPbeams-– s /2)/2 , mES= [(s/2 + pBpbeams- )2 /E2beams - p2B]½ q2 = (p + p)2 = (pB- p)2 toextractthesignalyield • q2 in 12 or 6 bins III Jornadas CPAN, Barcelona 39 A. Oyanguren

  40. Charm sl decays Analysisprocedure: • Partialreconstructionmethod; e+e-  cc; onlyelectrons • D* tag in case of DKe, no tagforDsor D+decays • Compute the D(s)directionfromalltracks  signaltracks • q2 and angular distributions: kinematicfitwithsignal • tracksmomenta and missingenergyinformation • Backgroundsuppressionusingeventshape and • topological variables • Background control, test of theanalysistechnique and thenormalization are obtainedfromhadronic data samples (ex: DK, D K) III Jornadas CPAN, Barcelona 40 A. Oyanguren

  41. [tobesubmittedto PRD] data Xu Xc B Xu 1441  102 Fitresults: • Most precise result : 2D fit q2-Mx • for p* > 1 GeV • FitforBXc bkg and BXu • signalyields B Xu B Xu Vubextraction: Average: |Vub|= (4.31 0.25exp  0.16theo )10-3 BNLP: [Bosch et al. , PRD 72 (05) 073006] DGE: [Andersen et al. , JHEP 0601 (06) 097] GGOU: [Gambino et al., JHEP 0710 (07) 058] ADFR: [Aglietti et al., EPJ. C 59 (09) 831] III Jornadas CPAN, Barcelona 41 A. Oyanguren

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