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Todd K. Pedlar The Ohio State University for the CLEO Collaboration Recent Results in B and D Decays from CLEO BEACH 2002, Vancouver June 26, 2002
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Todd K. Pedlar The Ohio State University The Rare Charmless Decays B K S 0 and K * Outline The Color Suppressed Decay B D 0 and Isospin Analysis of B D Introduction New Results from CLEO in D Mixing Conclusions
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June 26, 2002Todd K. Pedlar The Ohio State UniversityIntroduction These data were collected with the CLEO detector which observed symmetric e + e - collisions at the (4S) resonance, E cm = 10.56 GeVThese data were collected with the CLEO detector which observed symmetric e + e - collisions at the (4S) resonance, E cm = 10.56 GeV The CLEO detector provides both excellent tracking resolution and efficiency, as well as superb electromagnetic calorimetry.The CLEO detector provides both excellent tracking resolution and efficiency, as well as superb electromagnetic calorimetry. The hadronic B analyses presented in this talk are based on the CLEO II/II.V data sets of 9.67M BB pairsThe hadronic B analyses presented in this talk are based on the CLEO II/II.V data sets of 9.67M BB pairs The D mixing result is based on the 9 fb -1 CLEO II.V sample The D mixing result is based on the 9 fb -1 CLEO II.V sample
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June 26, 2002Todd K. Pedlar The Ohio State University The Color Suppressed Decay B D 0 and Isospin Analysis of B D
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June 26, 2002Todd K. Pedlar The Ohio State University Color Suppressed Decays: B D 0 The Internal spectator diagram is color-suppressed.The Internal spectator diagram is color-suppressed. Observation of color-suppressed decays is an important input for the theoretical understanding of hadronic B decaysObservation of color-suppressed decays is an important input for the theoretical understanding of hadronic B decays Until recently, only color- suppressed decays into charmonium states had been observed.Until recently, only color- suppressed decays into charmonium states had been observed. First Observations of B 0 D 0(*) 0 have been published by both Belle (PRL 88 052002) and CLEO (PRL 88 062001) Favored Suppressed
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June 26, 2002Todd K. Pedlar The Ohio State University Selection is based on reconstruction of D 0 in three decay modes (K - K - and K - - combined w/ prompt 0 ’sSelection is based on reconstruction of D 0 in three decay modes (K - K - and K - - combined w/ prompt 0 ’s Event yields obtained using an extended unbinned ML fitEvent yields obtained using an extended unbinned ML fit Color Suppressed Decays: B D 0 Event shapeB helicity angle Free parameters: N sig, N cont, N other BB Four input variables at right: PDFs for each obtained from off-res data + signal, generic BB and continuum MC.
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June 26, 2002Todd K. Pedlar The Ohio State University Br( B 0 D 0 0 x +0.36 - 0.32 hep-ex/0110055, Phys. Rev. Lett. 88 062001 Color Suppressed Decays: B D 0 (B0D00(B0D00
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June 26, 2002Todd K. Pedlar The Ohio State University With the observation of the color suppressed decay, all three D decays had been measured, making possible the estimation of the strong phase between the contributing isospin amplitudesWith the observation of the color suppressed decay, all three D decays had been measured, making possible the estimation of the strong phase between the contributing isospin amplitudes CLEO set out to measure the color-favored modes again, in order to improve the precision with which answers about this angle could be statedCLEO set out to measure the color-favored modes again, in order to improve the precision with which answers about this angle could be stated Isospin Analysis of B D decays
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June 26, 2002Todd K. Pedlar The Ohio State University Isospin Analysis of B D decays In B D decays, there are two isospin amplitudes (I=1/2 and 3/2) which contribute to the decay process In B D decays, there are two isospin amplitudes (I=1/2 and 3/2) which contribute to the decay process We can write the amplitudes for the three B D decays as follows: We can write the amplitudes for the three B D decays as follows:
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June 26, 2002Todd K. Pedlar The Ohio State University Isospin Analysis of B D decays We may express the two amplitudes in the following manner: We may express the two amplitudes in the following manner: And the phase difference between these amplitudes thus: And the phase difference between these amplitudes thus: cos I 1 final state interactions. Current PDG values, cos I 1 by just over 1
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June 26, 2002Todd K. Pedlar The Ohio State University CLEO has re-measured the two color-favored B D decays, B - D 0 - and B 0 D + -CLEO has re-measured the two color-favored B D decays, B - D 0 - and B 0 D + - In these measurements D 0 is reconstructed as before in 3 modes, (K - K - and K - - and D + in one (K - In these measurements D 0 is reconstructed as before in 3 modes, (K - K - and K - - and D + in one (K - Yields are obtained by simple ML fits to the data, which are subject to a very few cuts in E, event shape variables, etc, to attack BB and continuum backgrounds, respectivelyYields are obtained by simple ML fits to the data, which are subject to a very few cuts in E, event shape variables, etc, to attack BB and continuum backgrounds, respectively Isospin Analysis of B D decays
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June 26, 2002Todd K. Pedlar The Ohio State University The results of these measurements reflect improved precision with respect to the current PDG averagesThe results of these measurements reflect improved precision with respect to the current PDG averages These measurements are systematics, not statistics dominated. The two most significant syst. errors are external in nature:These measurements are systematics, not statistics dominated. The two most significant syst. errors are external in nature: –Individual D branching fractions (CLEO-c ?) –f 00 and f +- errors (help from BaBar / Belle ? ) Isospin Analysis of B D decays Br( B - D 0 - x x (PDG) Br( B 0 D + - x x (PDG)
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June 26, 2002Todd K. Pedlar The Ohio State University In addition, we have determined the strong phase difference cos I.In addition, we have determined the strong phase difference cos I. Using the combined measurements of Br(B 0 D 0 0 by CLEO and Belle, 2.92 0.45 x 10 -4, we have obtainedUsing the combined measurements of Br(B 0 D 0 0 by CLEO and Belle, 2.92 0.45 x 10 -4, we have obtained hep-ex/0206030, Submitted to PRD-RC Isospin Analysis of B D decays from unity
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June 26, 2002Todd K. Pedlar The Ohio State University The Rare Charmless Decays B 0 K S 0 and K *
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June 26, 2002Todd K. Pedlar The Ohio State University B 0 K S 0 and K * Recently there have been several observations of charmless two-body decays B K at CLEO and at the B factoriesRecently there have been several observations of charmless two-body decays B K at CLEO and at the B factories The pseudoscalar-vector companions to this decay, B K * and B K , provide useful additional information (including, ultimately, additional avenues for observing CP)The pseudoscalar-vector companions to this decay, B K * and B K , provide useful additional information (including, ultimately, additional avenues for observing CP) Here we present the observation of B 0 K S 0 , and of B 0 K *+ , based on the full CLEO II/II.V data set of 9.67 M BB pairs.Here we present the observation of B 0 K S 0 , and of B 0 K *+ , based on the full CLEO II/II.V data set of 9.67 M BB pairs.
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June 26, 2002Todd K. Pedlar The Ohio State University In the analysis of K S 0 , K S are selected by requiring 2.5 mass consistency and well-measured displaced secondary verticesIn the analysis of K S 0 , K S are selected by requiring 2.5 mass consistency and well-measured displaced secondary vertices In analyzing both the K S 0 and K + final states, very loose cuts are first applied on E, M BC, cos sph, cos B and a Fisher discriminant formed from a combination of event shape variables.In analyzing both the K S 0 and K + final states, very loose cuts are first applied on E, M BC, cos sph, cos B and a Fisher discriminant formed from a combination of event shape variables. Signal yields are obtained from a ML fit using PDFs for the above variables as in the color suppressed analysis.Signal yields are obtained from a ML fit using PDFs for the above variables as in the color suppressed analysis. The K * contribution to each final state sample above is obtained through simultaneous analyses of the Dalitz plotsThe K * contribution to each final state sample above is obtained through simultaneous analyses of the Dalitz plots B 0 K S 0 and K *
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June 26, 2002Todd K. Pedlar The Ohio State University We observe the rare B decay B 0 K S 0 (without regard to resonant substructure) with a signal significance of 8.1 We observe the rare B decay B 0 K S 0 (without regard to resonant substructure) with a signal significance of 8.1 hep-ex/0206024 Submitted to Phys. Rev. Lett. B 0 K S 0 and K * Br( B 0 K S 0 - (stat.) (syst.) x
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June 26, 2002Todd K. Pedlar The Ohio State University Simultaneous analysis of the Dalitz plots for both K S 0 and K + topologies reveals the process B 0 K *+ (892) with a signal significance of 4.6 Simultaneous analysis of the Dalitz plots for both K S 0 and K + topologies reveals the process B 0 K *+ (892) with a signal significance of 4.6 Most predictions for this BR are in the range 2-14 x 10 -6. Flavor SU(3) predictions (Chiang & Rosner) obtain 17.3 x 10 -6 (assuming maximal P-T interference)Most predictions for this BR are in the range 2-14 x 10 -6. Flavor SU(3) predictions (Chiang & Rosner) obtain 17.3 x 10 -6 (assuming maximal P-T interference) B 0 K S 0 and K * Br( B 0 K *+ - (stat.) (syst.) x K * /K S 20%
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June 26, 2002Todd K. Pedlar The Ohio State University New Results from CLEO in D Mixing
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June 26, 2002Todd K. Pedlar The Ohio State University Updated D mixing results from CLEO It’s not completely different – after all, we’re looking at the same final state of K s It’s not completely different – after all, we’re looking at the same final state of K s This analysis is based on 9 fb -1 of data collected with the CLEO II.V configuration (with SVX)This analysis is based on 9 fb -1 of data collected with the CLEO II.V configuration (with SVX) D * with p > 2 GeV are selected (favoring continuum-produced D* pairs), and the resulting D 0 are flavor tagged using the s from D * D 0 sD * with p > 2 GeV are selected (favoring continuum-produced D* pairs), and the resulting D 0 are flavor tagged using the s from D * D 0 s Reconstruction of the D* takes advantage of the very small vertical extent of the beam spotReconstruction of the D* takes advantage of the very small vertical extent of the beam spot
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June 26, 2002Todd K. Pedlar The Ohio State University D mixing - motivation x mixing: Channel for new physics… y mixing: SM background… * New physics will enhance x but not y * CP violation in mixing would be a smoking gun for new physics Two types of mixing:
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June 26, 2002Todd K. Pedlar The Ohio State University D mixing - methods Ultimately, need to fit proper decay time in order to distinguish mixing (both x and y) from doubly Cabibbo-suppressed (DCS) decays… Complication: phase difference, K , between CF and DCS amplitudes can lead to observable quantities x’ and y’, related to x and y by a rotation doublyCabibbosuppressed (R D ) mixing (x 2 +y 2 ) CabibboFavored (CF) (CF) “Wrong sign” Notation: “right-signed” (RS) => Cabibbo- favored decays “wrong-signed” (WS) => Mixing or doubly Cabibbo-suppressed decays “wrong-signed” (WS) => Mixing or doubly Cabibbo-suppressed decays Look for mixing in “wrong signed” (WS) decays of D 0 …
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June 26, 2002Todd K. Pedlar The Ohio State University Current D Mixing Limits “Typical” non-SM predictions (many higher and lower, however) “Typical” upper SM predictions If K unknown, WS hadronic limits must be weakened to accommodate any possible rotation SU(3) flavor symmetry badly broken=> Final state interactions expected to be important - K measurements are starting to cut into range of some non-SM predictions - LONG way to go before we hit SM levels
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June 26, 2002Todd K. Pedlar The Ohio State University D 0 K s 0 Motivation Measure x and y (not x ’2 and y ’ ) RS and WS occupy the SAME Dalitz plot: Thus making possible a measurement of relative strong phase between CF and DCS Only mode with sensitivity to sign of x! y sensitivity comparable to CP eigenstate (eg., D 0 ->K + K - ) analyses Complicated Dalitz plot and proper time fit required
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June 26, 2002Todd K. Pedlar The Ohio State University preliminary D 0 K s 0 Preliminary results
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June 26, 2002Todd K. Pedlar The Ohio State University D 0 K s 0 Preliminary results
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June 26, 2002Todd K. Pedlar The Ohio State University D 0 K s 0 Preliminary results The significance of the overall fit drops by 5 when WS K * is forced to zero.
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June 26, 2002Todd K. Pedlar The Ohio State University Phase convention: Final fit with 10 contributing intermediate states: Right sign First measurement of strong phase difference between CF and DCS! Wrong sign D 0 K s 0 Preliminary results Needed for extraction of in B DK Submitted to PRL
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June 26, 2002Todd K. Pedlar The Ohio State University Summary: D Mixing via D 0 K s 0 We have observed several contributions to the substructure in D 0 K s 0 including a wrong sign D 0 K *+ contribution at the 5 level, which must arise from either D mixing or DCSD We have observed several contributions to the substructure in D 0 K s 0 including a wrong sign D 0 K *+ contribution at the 5 level, which must arise from either D mixing or DCSD Separate fits for D 0 and D 0 tags have been performed, with no statistically significant difference observed (no CPV evident) Separate fits for D 0 and D 0 tags have been performed, with no statistically significant difference observed (no CPV evident) In addition, CLEO will have R D (I.e. the DCSD part of the WS/RS ratio), x, y, and A CP measurements from the time dependent version of this analysis very soon In addition, CLEO will have R D (I.e. the DCSD part of the WS/RS ratio), x, y, and A CP measurements from the time dependent version of this analysis very soon
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June 26, 2002Todd K. Pedlar The Ohio State UniversityConclusions CLEO has observed the color suppressed decay B 0 D 0 and made new measurements of color-allowed decays B 0 D + and B - D 0 . We have also presented a measurement of cos I which represents a strong suggestion of final state interactions in B D decays.CLEO has observed the color suppressed decay B 0 D 0 and made new measurements of color-allowed decays B 0 D + and B - D 0 . We have also presented a measurement of cos I which represents a strong suggestion of final state interactions in B D decays. We have presented new results for B 0 K S 0 and through an analysis of the Dalitz plot, a result for B 0 K *+ We have presented new results for B 0 K S 0 and through an analysis of the Dalitz plot, a result for B 0 K *+ We have presented a preliminary update of our measurements of D mixing, this time using D 0 K s 0 a promising channel for sensitive measurements of the mixing parameters x and y. Time dependent analysis of this mode is forthcoming.We have presented a preliminary update of our measurements of D mixing, this time using D 0 K s 0 a promising channel for sensitive measurements of the mixing parameters x and y. Time dependent analysis of this mode is forthcoming.
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