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23, June, 2005Beauty2005, Assisi, Italy Electroweak Penguin decays at Belle Akimasa Ishikawa KEK

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Flavor Changing Neutral Current Decays Flavor Changing Neutral Current decays, b s , b sll Forbidden at tree level induced through Penguin or Box diagrams at lowest order sensitive to heavy particles (SUSY, heavy Higgs) Observables Decay Width (Branching Fraction) Inclusive decay, theoretically clean, experimentally hard. Exclusive decays, large uncertainty due to form factor test of QCD in B decays Ratio of Decay Width Some theoretical and experimental uncertainties cancel Good probe also for exclusive decays! CP Asymmetry Isospin Asymmetry Up-Down Asymmetry BF ratio of electron mode to muon mode Forward-Backward Asymmetry Penguin diagram in the SM Beyond the SM diagram

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OPE and Wilson Coefficient Effective Hamiltonian is expressed in term of Operator Product Expansion. O 1,2 : current current operator O 3-6 : QCD penguin operator O 7,8 : electro- and chromo-magnetic operator O 9,10 : semileptonic operator C i : Wilson coefficient Wilson coefficient is a strength of corresponding short distance operator. Precise measurement of Wilson coefficients is one of the goals for B physics. For b s and b ll case, only O 7, O 9 and O 10 appear in the Hamiltonian. New Physics changes the Wilson Coefficients

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b s and b sll decays can be extracted from B(b s ), B(b sl l ) and A FB (b sl l ) ! Decay widths for b s and b sll can be described with Wilson coefficients. Absolute value of can be measured. Interference terms (sometimes we do not use C i but A i which is leading coefficient) Relative signs can be also determined from interference terms!! In the SM

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Branching Fraction of B K* b s was observed at CLEO in K* K* is reconstructed from 4 modes K + -, K s 0, K + 0, K s + |M K* M K | < 75MeV Better than 10% accurary! Theoretical preduction QCD fact. (70 25) LEET (68 23) pQCD (35 10) Lattice (35 16) B(B 0 K *0 ) = (40.9 2.1 1.9) B(B + K *+ ) = (44.0 3.3 2.4) Theoretical uncertainties are large 80/fb data K* K 2 *(1430)

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Asymmetry in B K* Isospin Asymmetry 0+ is sensitive to sign of Wilson coefficients C 6 /C 7 0+ = +5~10% and C 6 /C 7 >0 in the SM If C 6 /C 7 <0, 0+ <0. Direct CPV is less than 1% in the SM 5% CPV is allowed in new physics A CP = (-0.1 4.4 0.8)% 0+ = (+3.4 4.4(stat) 2.6(syst) 2.5(f +- /f 00 ))% B0B0 B0B0 A.Kagan and M.Neubert, PLB 539, 227 (2002)

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Time dependent CPV in B K s 0 Not only the K* 0 , but any K s 0 can be used for TCPV measurement. In the SM, S<0.1, A<0.01. Right handed currents induce large value of S S corresponds to fraction of C 7R to C 7L M Ks < 1.8GeV 250/fb data K* K 2 *(1430) Atwood, Gershon, Hazumi, Soni PRD71 (2005) First Measurement

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Observation of B K K s can be used for time dep. CPV measurement to search for right handed currents. B K + , K s is reconstructed from and 0 M K < 2.4GeV First Observation 250/fb data B0B0 B0B0

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Observation of B K 1 (1270) B K final state via K 1 can be used for up-down Asymmetry to search for right handed currents. K 1 (1270) is reconstructed from K + + - and K s + -. 0.6< M < 0.9GeV ( mass region) to enhance K 1 (1270) Resonance components are extracted by fitting to the hadronic mass distribution. First Observation 140/fb data M.Gronau et al. PRL (2002)

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Observation of B p Baryon production via weak decay of meson Near threshold enhancement of di- baryon system is observed in B p (b s process) Near threshold enhancement also observed Fragmentation? First Observation 140/fb data Theoretical prediction ~10 -6

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Inclusive B X s Full inclusive b Photon with E>1.8GeV Veto photons from 0 and Subtract continuum with off-resonance data Moment analysis to extract HQET parameter = ± ± GeV - 2 = ± ± GeV 140/fb data HQET parameter used to extract V cb and V ub

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BF of Inclusive B X s Subtract b d assuming B(b d )/B(b s ) = 3.8 ± 0.6% Measured BF is consistent with theoretical predictions. M H+ >200GeV 95%CL (M.Neubert CKM2005) Limit on Wilson coefficient A 7 < A 7 < or 0.21< A 7 < 0.42 In the SM A 7 = at = 2.5GeV G.Hiller and F.Krueger PRD 69 (2004)

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Exclusive B X s / Inclusive b s 40% of b s are measured exclusively. Next step : B 0 K 0 S 0 for TCPV analysis. K ’, Kf 0, Ka 0 ….. K* K 1 (1270) K 2 *(1420) K* KK KK KK pp 59 ±6.0% missing Isospin symmetry for B and K* decay is assumed

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Search for B b d process has not been observed Simultaneous fit to B - - , B 0 0 and B 0 From isospin relations: constrain |V td /V ts | B(B - - ) = 2 ( (B - )/ (B 0 )) B(B 0 0 ) = 2 ( (B - )/ (B 0 )) B(B 0 ) B(B ( , ) ) = B(B - ) < 1.4 /fb data SM predictions: B(B - - ) = (0.90 ± 0.34) (Ali-Parkhomenko) B(B - - ) = (1.50 ± 0.50) (Bosch-Buchalla) R : form factor ratio : SU(3) breaking effect Just above the SM prediction!!

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Inclusive B X s ll Semi-inclusive technique Electron or muon pair M ll >0.2GeV Charmonium veto Xs is reconstructed from K + or K s (at most one 0 is allowed) M Xs < 2.0 GeV 140/fb data Theoretical preduction by Ali et al. Wrong flavor M Xs q2q2

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Limit on Wilson Coefficients Clean prediction of BF of B(B X s ll) for 1(2m ) ±1.15.6±2.04.5±1.04.4±0.78.8±0.7 1

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Branching Fraction of B K ( * ) ll K +, K s or K*(K + -, K s +, K + 0 ) + e + e - or + - M ll >0.14GeV A ratio of BF of K ( * ) to K ( * ) ee is sensitive to neutral heavy Higgs in 2HDM with large tan . In the SM, the ratio is 1.00 and ~0.75 for Kll and K*ll 250/fb data Prediction by Ali et al. Y. Wang and D. Atwood PRD68 (2003) G.Hiller and F.Krueger PRD 69 (2004)

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First look at A FB in K*ll Sign of C 7 C 10 can be determined from Forward- Backward Asymmetry in K*ll. Raw A FB in each q 2 region is extracted from M bc fit. Kll has no asymmetry, so it is a good control sample. Curves show theoretical distributions including experimental efficiency effect (not fitted lines! ). Both curves are in agreement with data, so far. A FB K* l l Ali et al. Phys.Rev. D61 (2000) SM q2q2

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Summary Many results for BF are consistent with the SM Precision of BF(b s ) is 15% level. Negative A 7 solution is consistent with the SM A 7 value Upper limit on B(B ( ) ) is just above the predictions Constrain |V td /V ts | Improved measurement of inclusive B Xsll decay Sign of C 7 flipped case with SM C 9 and C 10 values is unlikely stringent limits on C 9 and C 10 Many measurements of Ratio Precisions of 0+ (B K* ) are 5% level Towards sign of (C 6 /C 7 ). Time dep. CPV in B K s 0 is measured for the first time Search for right handed component in C 7 First look at Forward-Backward Asymmetry in B K*ll Will be used for measurement of A 9 and A 10 New results will be presented at Lepton Photon 05. Stay tuned

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Backup Slides

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A FB at Super Belle 1 year running at 5x10 35 /nb/sec 5/ab integrated luminosity, 10 billion B mesons!! We have accumulated ~0.46/ab, about x10 A 9 /A 9 ~11%, A 10 /A 10 ~13% A 7 fixed to SM value systematic error is not included Belle Toy MC with 5/ab C 10 NP C 9 NP Donut : B(B Xsll) with140/fb A FB K*ll with 5/ab

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