Paul Bloom*, Phil Clark, Wolfgang Gradl and Alan Robertson. pclark. *Swarthmore College University of Edinburgh I V

Transcript

1 Rare B decays B η K & B η ρ Paul Bloom*, Phil Clark, Wolfgang Gradl and Alan Robertson pclark *Swarthmore College University of Edinburgh E U N I V E R S I T Y T H O H F E D I N B U R G University of Edinburgh 13th April 6 p. 1/6

2 Overview Contents of talk Introduction to charmless two body decays Theoretical predictions and previous results Status of BaBar and PEPII Analysis details (selection, fit, backgrounds) Results and systematics Conclusion Chosen to focus on one particular analysis The search for four modes (charged and neutral) B η K and B η ρ Territory of rare B decays being explored rapidly... Philip J. Clark, University of Edinburgh p. /6

3 CLEO Belle K + π ωρ + CDF PDG New Avg. ηπ + π π + π π + K + π K + K K + K (13) π + Charmless B Branching Fractions K + ρ K K π+ + ρ K + ρ K(13) + π K π K + K S K S ρ + π K + π ηk ρ π ± K π + K + K K ηk + ρ + ρ ρ + ρ ηk + π K + π π K π + π a 1 π + η K HFAG JULY 1th... K K K + K π π ρ π φφk + ηk + η π + π + π K + ρ K f (98) ηπ + K + π + π (NR) K ρ π + π K S K S K S ωk + ωk ωπ + K + π K(13) π ηρ + φk φk + K + f (98) Branching Ratio x 6 K + π + π ρ π + φk + φk... η K + Philip J. Clark, University of Edinburgh p. 3/6

4 Quasi Two Body Decays J P C classification of light meson decays PP B ηk, ππ, η π... VV B ρρ, φk, φω... PV B η K, η ρ, πφ,... SP B a π, f π... B η K and B η ρ are PV decays Philip J. Clark, University of Edinburgh p. /6

5 SU() multiplets Meson pseudoscalar and vector 16-plets based on central su(3) nonets (excluding η c and J/ψ) shown also are the baryon -plets (su(3) octet and decuplet based) Philip J. Clark, University of Edinburgh p. /6

6 The η & η quark content SU(3) nonet consists of singlet and octet states (3 3 = 8 1) η 1 = 1 3 (uū + d d + s s) η 8 = 1 6 (uū + d d s s) Physical η and η states are octet-singlet mixed states: η η = η 1 sin θ η 8 cos θ = η 1 cos θ + η 8 sin θ Assuming a mixing angle θ = (vector mesons θ = 3 ) η = 1 3 (uū + d d s s) η = 1 6 (uū + d d + s s) Philip J. Clark, University of Edinburgh p. 6/6

7 Theoretical Approaches (1) Diagrammatic methods Methodology Isospin & SU(3) Advantages very intuitive powerful relations Disadvantages SU(3) breaking a priori information non exact results (a) T p (b) C v (c) P v (d) P p Philip J. Clark, University of Edinburgh p. 7/6

8 Theoretical Approaches () Effective Hamiltonian Methodology QCD operator product expansion Wilson coeffs operators Advantages Better handling of QCD corrections Disadvantages Huge uncertainties in operator matrix elements One approach is QCD factorisation Other approaches: Soft Collinear Effective Theory & perturbative QCD factorization Philip J. Clark, University of Edinburgh p. 8/6

9 B η K diagrams One loop b s penguins expected to dominate CKM and colour suppressed internal trees B b u,d W + g s s η s K +,K u,d B b u,d W + g s K +,K u,d ū, d u,d η CKM suppressed external tree for B + η K + B η K diagrams identical to η K Variety of possible singlet and rescattering diagrams b W + B d g b B W + u,d g ū u s d η K η s K +,K u,d b W + B + u W + ū u s u η K + K + b B + ū η u u u s Philip J. Clark, University of Edinburgh p. 9/6

10 η η puzzle The decays η K and B ηk are large B(B η K ) = 63. ± 3.3 B(B + η K + ) = 69. ±.7 B(B ηk ) = 18.7 ± 1.7 B(B + ηk + ) = but why are B ηk and η K small? B(B ηk ) < 1.9 B(B + ηk + ) =. ±.3 B(B η K ) < 7.6 B(B + η K + ) < 1 Various theory explanations sum rule put forward by Lipkin η charm content HFAG July Philip J. Clark, University of Edinburgh p. /6

11 B(B (η, η ) (K ( ), π, ρ) CLEO Belle PDG New Avg. HFAG April 6 ηπ ηπ + ηk ηk + ηρ ηρ + ηk ηk + η π η π + η ρ η ρ + η K η K + η K η K +... Branching Ratio x 6 Philip J. Clark, University of Edinburgh p. 11/6

12 B η ρ diagrams CKM and colour suppressed internal trees b B W + ū u η d ρ +,ρ b B W + ū u d ρ η One loop b d penguins u,d u,d d d CKM suppressed external tree for η ρ + η ρ expected to be small b B u,d W + g d d η d ρ +,ρ u,d b B u,d W + g d ρ +,ρ u,d ū, d u,d η Internal trees cancel η 1 6 (uū + d d + s s) ρ 1 (uū d d) b B W + u,d g η d g ρ +,ρ u,d W + u d ρ + b B + ū η u u Philip J. Clark, University of Edinburgh p. 1/6

13 Motivation Decay mode Theoretical predictions Experimental status SU(3) flavor QCD fact. HFAG(7/) BaBar Belle B η K < 7.6 < 7.6 < B + η K < 1 < 1 < 9 B η ρ <.3 <.3 < 1 B + η ρ < < Use increased dataset (run1-) to tighten upper limits Try to constrain theory predictions Might get lucky (c.f. run1- yields) S(η K ) =.1σ S(η K + ) = 1.9σ S(η ρ + ) =.6σ Magnitude of η K suppression vs. η K enhancement Philip J. Clark, University of Edinburgh p. 13/6

14 PEPII at SLAC Asymmetric collisions: 9.1 GeV e / 3.1 GeV e + Construction started in 199 completed in 1999 e + e Υ (S) B B Design luminosity in Philip J. Clark, University of Edinburgh p. 1/6

15 Integrated luminosity //6 :19 //6 : -1 Luminosity per Day [pb ] 7 6 BaBar Run 1- Delivered Luminosity Recorded Luminosity ] -1 Integrated Luminosity [fb 3 3 BaBar Run 1- PEP II Delivered Luminosity: 3.71/fb BaBar Recorded Luminosity: 39./fb Off Peak Luminosity: 8.3/fb Delivered Luminosity Recorded Luminosity Off Peak Long downtime (electrical accident) Luminosity problems so far in 6 Philip J. Clark, University of Edinburgh p. 1/6

16 Luminosity trends Peak luminosity (cm - s -1 ) Increase of Peak Luminosity KEKB PEP-II 6 Year Peak luminosity (cm - s -1 ) Peak Luminosity trends in last 3 years ISR SPEAR PEP PETRA TRISTAN DORIS Excellent performance of the B factories Design luminosity KEKB 1 3 cm s 1 PEPII 3 33 cm s 1 Instantaneous luminosity frontier SppS LEP1 CESR KEKB PEP II TEVATRON LEP HERA Year Philip J. Clark, University of Edinburgh p. 16/6

17 The BaBar detector Philip J. Clark, University of Edinburgh p. 17/6

18 Datasets The data sample for this analysis is fb 1 at Υ (S) corresponding to (31.8 ±.6) million BB pairs. Monte Carlo samples typically 1k events per mode For B background studies we use 67 million generic BB events. Previous analysis data sample was 8 fb 1 Published: Phys. Rev. D7, 36 () Contains good description of analysis techniques Philip J. Clark, University of Edinburgh p. 18/6

19 BaBar kinematics Energy substituted mass: m ES = (s/ + p p B ) /E p B Energy difference: E = E B s/ GTL = Good Tracks Loose doesn t include short tracks GTVL = Good Tracks Very Loose includes short tracks Events / (. GeV ) Events / (.81 GeV ) χ f C µ C µ T σ C σ T / ndf = 8.99 =.93 ±.6 =.796 ±.1 GeV =.799 ±.9 GeV =.83 ±. GeV =.91 ±.6 GeV m ES (GeV) χ f C µ C µ T σ C σ T / ndf =.766 =.737 ±.61 = -.19 ±. GeV = -.78 ±.17 GeV =.13 ±.1 GeV =.976 ±. GeV E (GeV) Philip J. Clark, University of Edinburgh p. 19/6

20 Helicity of the vector meson (ρ or K ) B P V B spin decaying to spin + spin 1 final state Vector meson can only take on one spin polarisation Define helicity cos θ H (cosine of angle between daughter π and negative B direction in vector meson frame) signal has cos θ shape Events / (.87 ) χ / ndf = p 1 = -.8 ± 6. p p 3 p = 11 ± 696 = -9. ± 3 = -7. ± cos θ hel K* Philip J. Clark, University of Edinburgh p. /6

21 Some analysis Improvements 3 1 Truth Matched GTVL GTL Events / (. GeV ) f core =.6±.18 µ core =-.9±.6 µ tail =-.388±.3 σ core =.779±.76 σ tail =.119±.6 χ /n= Helicity of ρ m / (GeV) #de Self cross-feed GTVL GTL Helicity of ρ Events / (. GeV ) f core =.6±.13 core =-.991±.7 µ tail =-.36±.3 core =.8±. σ =.93±.6 tail χ /n= m / (GeV) GTL GTVL for ρ and K meson daughter pions Mass constrain η and η for B candidates (..) < m ES <.9 #de Philip J. Clark, University of Edinburgh p. 1/6

22 Skim selection Inclusive skim (for case η ηππ) 1.9 GeV/c < p < 3.1 GeV/c Exclusive skim (for case η ργ) Necessary due to larger backgrounds Look for 16 B η X decays 1.9 GeV/c < p < 3.1 GeV/c m B >.1 GeV/c E <.3 GeV E γ >. GeV Final state Signal efficiency (%) q q efficiency (%) η K 3.8 η ρ /ρ + 8/36 <. Philip J. Clark, University of Edinburgh p. /6

23 Event selection ten decay modes η ηππk K + π, η ργk K + π η ηππk + K + π, η ργk + K + π η ηππk + K π +, η ργk + K + π η ηππρ, η ργρ η ηππρ +, η ργρ + K S candidate lifetime τ/σ t > 3 Particle identification e/p/k veto for pions tight ID for kaons Criterion Requirement η γγ 9 < m(γγ) < 6 η ηππ 9 < m(ηππ) < η ργ 9 < m(ργ) < KKπ 7 < m(kπ) < 3 ρ + 7 < m(ππ) < 7 ρ < m(ππ) < 6 π 1 < m(γγ) < 1 K S 86 < m(ππ) < γ (from η) E γ < γ (from π ) E γ < 3 γ (from η ) E γ < N trks max[3, N trks in decay mode + 1] Fisher, F < F < m ES. m ES <.9 GeV/c Philip J. Clark, University of Edinburgh p. 3/6

24 qq background rejection (1) Rare charmless decays small signal / large background two body kinematics help remove background Dominant remaining background is qq continuum Reject jet-like topologies Define thrust axis and cut on angle cos θ T <.9 η ηππ modes cos θ T <.7 η ργ modes Philip J. Clark, University of Edinburgh p. /6

25 qq background rejection () Many other event shape variables, all highly correlated Distinguish signal from qq with Fisher (F) discriminant cos θ B, θ B angle between p B and beam axis cos θ C, θ C angle between candidate thrust axis and beam Legendre Polynomials P and P, angular distribution of rest of event momentum flow wrt. B thrust axis Linear weights are applied to each variable to maximise S to B separation. Philip J. Clark, University of Edinburgh p. /6

26 BB backgrounds Mainly backgrounds picking up extra particle (eg. B η K) E and helicity cuts help. < E <.1 (. < E <.1 modes with π ) cos θ H >.9 removes slow π + combs For π modes we remove slow π + or slow π combs.8 < cos θ H <.9 η ηππ modes.7 < cos θ H <.9 η ργ modes Identify remaining BB using generic MC then dedicated signal MC (added a 1 ρ/k ) η ηππmodes have less BB background than η ργ (have not unblinded η ργρ) Signal mode (B η K ) Mode # MC ɛ Est. B Q B i Norm. # # in PDF Bkg. channel (%) ( 6 ) BB B kg. Bkg. file B + η η γγ ππk B η 3π K K + π B η η γγ ππk S B a 1 K (L, f L =.7) B ω K K + π (L, f L = 1) B + a + 1 (ρ+ π )K (L, f L =.7) Philip J. Clark, University of Edinburgh p. 6/6

27 Some modes have large BB backgrounds η ργmodes have -3 BB bkgs All modes: 3 bkgs Dropped η ργρ + and η ργρ Statistical power small Systematics huge Philip J. Clark, University of Edinburgh p. 7/6

28 Maximum likelihood fit details P L = e ( nj ) N! N i=1 L i, where L i = m j=1 n j P j (x i ) Fit components, n j, for signal, qq and BB For η ρ we include an extra component η f Variable (x i ) Signal (P) Continuum (P) BB background (P) E G + G P 1 G + P 1 m ES G + G ARGUS ARGUS + G + G F BG + G BG + G BG + G m η G + G P 1 + (G + G) sig P 1 + (G + G) sig m K BW P + (BW ) sig P + (BW ) sig m ρ BW P + (BW ) sig P + (BW ) sig cos θ H P P EXP + P Philip J. Clark, University of Edinburgh p. 8/6

29 core pdfs η ηππ K sig qq BB E Events / (. GeV ) χ / ndf = Cf=.737 ±.61 8 µ C= -.19 ±. GeV 7 µ T= -.78 ±.17 GeV 6 σ C=.13 ±.1 GeV σ T=.976 ±. GeV E (GeV) Events / (. GeV ) 3 χ/ ndf =.631 p 1= -1. ±. p = -.9 ± E (GeV) Events / (. GeV ) χ/ ndf =.663 fracdech =.81 ±.7 µ= -.8 ±.18 GeV σ=. ±. GeV p 1=. ±.96 p = 16. ± E (GeV) m ES Events / (. GeV ) 6 3 σ T=.91 ±.6 GeV σ C=.83 ±. GeV µ T=.799 ±.9 GeV µ C=.796 ±.1 GeV Cf=.93 ±.6 χ / ndf = (GeV).9 m ES Events / (. GeV ) 16 χ / ndf = ξ= -9. ± (GeV) m ES Events / (. GeV ) 8 6 χ / ndf =.761 ξ= -6. ±17 argus f =.8 ±.61 Cf=.3 ±.1 µ C=.836 ±.73 GeV µ T=.7737 ±.9 GeV σ C=.163 ±.3 GeV σ T=.38 ±.11 GeV (GeV).9 m ES F Events / (.6 ) χ / ndf = A =.1 ±. µ= -.8 ±.37 σ=.6 ±.31 µ= -.39 ±.16 σ= 1.98 ±.1 FS= f.9868 ±. Events / (.6 ) 3 χ / ndf =.69 A C=.7 ±.3 1 µ C=.37 ±.11 σ C=.7 ±. µ T=.6 ±.19 σ T= 1.7 ±.3 FBG f =.98 ±.1 Events / (.6 ) 1 χ/ ndf =.68 A C=.13 ±. µ C= ±.17 σ C=. ±.1 f =.98 ±. µ T= -.37 ±.6 σ T= 1.9 ± fisher fisher fisher cos θ H Events / (.13 ) χ / ndf = 1.18 p 1= -.8 ± 6. 3 p = 11 ±696 p 3= -9. ± 3 p = -7. ± cos θ hel K* Events / (.13 ) 3 χ/ ndf = p 1= -.76 ±.9 p =. ±.8 p 3= -.9 ±.1 p =.6 ± cos θ hel K* Events / (.13 ) / ndf =.33 χ frachkstarch =.671 ±. 8 6 c = -. p 1= 3.17 ±.7 p = 6.1 ±1.9 ± cos θ hel K* m K Events / (. ) χ/ ndf = µ=.89 ±.3 σ=. ± m K* Events / (. ) 7 χ / ndf = K*= f. ±.8 p 1=. ±.38 p = -.63 ± m K* Events / (. ) 3 χ / ndf =.93 1 K*= f.31 ±.7 p 1=.63 ±.66 p = -. ± m K* m η Events / (.3 ) / ndf = χ Cf=.876 ±. 6 3 µ C=.9771 ±.9 µ T=.988 ±.9 σ C=.368 ±.9 σ T=.176 ± m 1 η Events / (.3 ) f 6 χ/ ndf =.666 E =.17 ±.1 p 1=.76 ±.31 p =.13 ± m 1 η Events / (.3 ) χ / ndf = 1.77 ηf=.1 ± p 1=.399 ±.6 p =.179 ± m 1 η Philip J. Clark, University of Edinburgh p. 9/6

30 1 C T C C core pdfs η ργ K sig qq BB E Events / (. GeV ) 8 6 / ndf = E (GeV) χ f C µ C µ T σ C σ T =.796 ± = ± =. ± =.168 ± =.96 ±.7.1 GeV.9 GeV.1 GeV. GeV Events / (. GeV ) 1 1 / ndf = 1.3 = -1.1 ±.11 = 1. ± E (GeV) χ p p Events / (. GeV ) 3 χ / ndf = 1.8 fracdech =.168 ±.8 µ = ±.9 GeV σ =. ±.1 GeV p 1 = -1.9 ±.7 p =. ± E (GeV) m ES Events / (. GeV ) 6 3 σ T σ C µ T µ C f C χ =.96 ± =.688 ± =.7 ± =.796 ± =.9163 ± / ndf = GeV. GeV.7 GeV.1 GeV (GeV).9 m ES Events / (. GeV ) χ / ndf =.99 3 = -.33 ± (GeV).9 ξ m ES. Events / (. GeV ) χ / ndf = ξ = -8. ±. f argus =.639 ±.19 3 f =.8 ±.69 C µ C =.831 ±.37 GeV 3 µ T =.768 ±. GeV σ =.3 ±. GeV σ T =.6 ±.3 GeV (GeV).9 m ES F Events / (.6 ) χ / ndf =.6 3 A = -. ± µ = ± σ =.8 ± µ = -1.3 ± σ =.88 ± f FS =.998 ±.1 Events / (.6 ) 3 χ A µ C σ C µ / ndf =.6 = -.33 ±.1 = -.86 ±.3 =.7 ±.38 =.77 ±.83 σ = 1.86 ±. T f FBG =.9 ±. Events / (.6 ) 3 χ A µ C σ C f µ T σ T / ndf =.88 = -.3 ±. = ±.7 =.9 ±.7 =.996 ±.3 = -1. ±.6 =.38 ± fisher fisher fisher cos θ H Events / (.13 ) χ p 1 p p 3 p / ndf =.81 = 11. ± = 66 ± = -1. ± = ± cos θ 1 hel K* Events / (.13 ) χ / ndf = p 1 = -.88 ±. p =.1 ±.1 p 3 = ±.76 p =.77 ± cos θ 1 hel K* Events / (.13 ) χ / ndf = 1.9 frachkstarch =. ± c = ± p 1 p cos θ 1 hel K* 1. = -.1 ± = 3.1 ±..33 m K Events / (. ) 8 6 / ndf = m K* χ µ =.89 ± σ =.89 ±..8 Events / (. ) 3 1 / ndf = m K* χ f K* p 1 p =.31 ± =.6 ± =.8 ± Events / (. ) / ndf =. χ =.76 ± m K* f K* p 1 p =.3 ± = -.8 ±.7.1 m η Events / (.3 ) 1 / ndf = m 1 η χ f C µ C µ T σ C σ T =.6 ±.1 =.971 ± =.93 ± =.73 ± =.83 ± Events / (.3 ) 6 3 χ f E p 1 p / ndf = 1.37 =.3 ±.1 =.1 ±.1 = -.61 ± m 1 η Events / (.3 ) χ / ndf = f η =.8 ±.1 p 1 =. ±.7 p = -.89 ± m 1 η Philip J. Clark, University of Edinburgh p. 3/6

31 Toy Monte Carlo Studies Determine ML fit yield bias Signal and BB events embedded from SP/6 MC Continuum qq events generated from PDFs Mode N total N sig N BB N sig N BB σ(n sig ) σ(n BB ) bias (in) (in) (fit) (fit) (fit) (fit) [evts] η ηππk ±.3.9 ± ±.3 η ργ K ±.6. ± ±.6 η ηππk + K π ±. 16. ± ±. η ργk + K π ±. 8. ± ±. η ηππk + K + π ±. 7 ± ±. η ργk + K + π ± ± ±.6 η ηππρ ± ± ±.7 η ηππρ ±.7 9 ± ±.7 Philip J. Clark, University of Edinburgh p. 31/6

32 Neutral Modes B η K /ρ ML fit quantity η ηππk η ργk η ηππρ /η ηππf η ργρ /η ργf Events to fit signal yield / blind Fit BB yield blind ML-fit bias (events) /-3.8 blind MC ɛ (%) / /7.8 Tracking corr. (%) Neutral corr. (%) Corr. ɛ (%) /. 17.8/7.6 Q Bi (%) /17. 9./66.7 Corr. ɛ Q B i (%). 3.3./..3/.1 Stat. sign. (σ).1../. blind B( 6 ) / blind UL B ( 6 ) /. blind Combined results B( 6 ) / Signif...3/. UL B( 6 ) 3.7/. Philip J. Clark, University of Edinburgh p. 3/6

33 Charged Modes B + η K /ρ ML fit quantity η ηππk + K π + η ργk + K π + η ηππk + K + π η ργk + K + π η ηππρ + η ργρ + Events to fit Signal yield blind BB yield ± 6 blind ML-fit bias (events) blind MC ɛ (%) Tracking corr. (%) K S corr. (%) Neutrals corr. (%) Corr. ɛ (%) Q Bi (%) Corr. ɛ Q B i (%) Stat. sign. (σ) blind B( 6 ) blind UL B ( 6 ) blind B( 6 ) Signif. w syst. (σ) UL B( 6 ) Philip J. Clark, University of Edinburgh p. 33/6

34 E mes F cos θh mk mη splots η ηππ K sig qq BB E (GeV) E (GeV) Events / (. GeV ) Events / (. GeV ) Events / (. GeV ) E (GeV) (GeV) m ES (GeV) m ES Events / (. GeV ) Events / (. GeV ) Events / (. GeV ) (GeV) m ES fisher - - fisher Events / (.6 ) Events / (.6 ) Events / (.6 ) fisher cos θ hel K* cos θ hel K* Events / (.13 ) Events / (.13 ) Events / (.13 ) cos θ hel K* m K* m K* Events / (. ) Events / (. ) Events / (. ) m K* m η 3 1 Events / (.3 ) Events / (.3 ) Events / (.3 ) m η m η Philip J. Clark, University of Edinburgh p. 3/6

35 splots η ηππ K + K π + sig qq BB E E (GeV) E (GeV) E (GeV) m ES (GeV) M ES (GeV) M ES (GeV) M ES F fisher fisher fisher cos θ H H Kpi H Kpi H Kpi m K M Kpi M Kpi M Kpi m η M etapipi M etapipi M etapipi Philip J. Clark, University of Edinburgh p. 3/6

36 B η ηππk Projection plots Events / (. GeV ) 18 * η K 16 ηππ (GeV) B η ργk m ES Events / (. GeV ) * 16 η K ηππ E (GeV) Events / (. GeV ) * η K ργ (GeV) m ES Events / (. GeV ) η K 6 ργ * E (GeV) Philip J. Clark, University of Edinburgh p. 36/6

37 B + η ηππk + K π + Events / (. GeV ) η K π ηππ *+ K S (GeV) B + η ργk + K π + Events / (. GeV ) 1 η ργ K *+ K π + S Projection plots m ES (GeV) m ES Events / (. GeV ) Events / (. GeV ) η ηππ K *+ K π + S E (GeV) *+ η K ργ K π + S E (GeV) Philip J. Clark, University of Edinburgh p. 37/6

38 B + η ηππρ + Projection plots Events / (. GeV ) η ρ 3 + ηππ (GeV) B η ηππρ m ES Events / (. GeV ) η ρ + ηππ E (GeV) Events / (. GeV ) η ηππ ρ (GeV) m ES Events / (. GeV ) η ρ ηππ E (GeV) Philip J. Clark, University of Edinburgh p. 38/6

39 Likelihood ratio plots Events/bin 3 η ηππk Events/bin 3 η ηππk + K + π Events/bin 3 η ηππk + K π + Events/bin 3 η ηππρ L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] Events/bin 3 η ργk Events/bin 3 η ργk + K + π Events/bin 3 η ργk + K π + Events/bin 3 η ηππρ L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] L(S)/[L(S)+L(B)] L sig /[L sig + L bkg ] for all modes. Points are on-peak data, background qq & BB expectation (pure toy) signal (pure toy) + background Philip J. Clark, University of Edinburgh p. 39/6

40 Systematics B η K /ρ Quantity η ηππk η ργk η ηππρ /η ηππf Multiplicative errors (%) Track multiplicity (C) Tracking efficiency [C]..6. π /η γγ /γ eff [C] Number BB [C] cos θ T [C]. 3.. Branching fractions [U] /3. MC statistics [U].6.6. Total multiplicative /7. Additive errors (events) Signal Model [U] ±. ±.83 ±1./.8 Fit bias [U] ±.9 ±.8 ±.7/. BB background [U] /3.6 Total additive (events) Total errors [B( 6 )] Total Additive Uncorrelated / / /+.. Correlated ±.6 ±. ±.3/.1 Philip J. Clark, University of Edinburgh p. /6

41 Systematics B + η K /ρ Quantity η ηππk + K π + η ργk + K π + η ηππk + K + π η ργk + K + π η ηππρ + Multiplicative errors (%) Track multiplicity [C] Tracking efficiency [C] π /η γγ /γ eff [C] Number BB [C] cos θ T [C] Branching fractions [U] MC statistics [U] Total multiplicative (%) Additive errors (events) Signal model [U] ±.3 ±1.1 ±.13 ±1.6 ±1.6 Fit bias [U] ±. ±1. ±. ±1.3 ±6.8 BB background [U] Total additive (events) Total errors [B( 6 )] Total Additive Uncorrelated Correlated ±. ±.31 ±.7 ±.19 ±. Philip J. Clark, University of Edinburgh p. 1/6

42 Log likelihood scan plots ) - ln (L/L η K combined incl. syst. ) - ln (L/L. 1. η ρ incl. syst BR(B η K * ) ( -6 ) BR(B η ρ ) ( -6 ) ) - ln (L/L 3 η K combined incl. syst. ) - ln (L/L 1 η ρ + incl. syst BR(B η K *+ ) ( -6 ) BR(B η ρ ) ( ) Philip J. Clark, University of Edinburgh p. /6

43 B η f ( π + π ) Events / (. GeV ) η 1 f ηππ (GeV) m ES Events / (. GeV ) η ηππ f E (GeV) - ln (L/L ) Events/bin BR(B η f ) ( ) L(S)/[L(S)+L(B)] Philip J. Clark, University of Edinburgh p. 3/6

44 Comparison to predictions Central values agree well with QCD factorisation predictions Also agree with SU(3) numbers As expected B η ρ is probably very small New upper limit for B η f ( π + π ) Decay mode Theoretical predictions Experimental results SU(3) flavour QCD fact. HFAG BaBar Belle New results B η K B + η K < 7.6 < 7.6 < < 1 < 1 < (. σ) (3.6 σ) < 7.9 B η ρ B + η ρ <.3 <.3 < < < B η f ( π + π ) (.3 σ) < 3.7 (.3 σ) < 1 (. σ) <. Philip J. Clark, University of Edinburgh p. /6

45 B(B (η, η ) (K ( ), π, ρ) CLEO Belle PDG New Avg. HFAG April 6 ηπ ηπ + ηk ηk + ηρ ηρ + ηk ηk + η π η π + η ρ η ρ + η K η K + η K η K +... Branching Ratio x 6 Philip J. Clark, University of Edinburgh p. /6

46 Conclusions Measurement of η K and evidence for η K + New upper limits for B η ρ and B + η ρ + Level of B η K enhancement wrt. B η K η Decay mode B( 6 ) η B η K (. σ) B ηk 18.7 ± 1.7 K B + η K (3.6 σ) B+ ηk B η K 63. ± 3.3 B ηk < 1.9 K B + η K ±.7 B + ηk +. ±.3 Philip J. Clark, University of Edinburgh p. 6/6