Measurement of D0-D0bar mixing and search for CP violation in D0 -> K+K-, pi+pi- decays with the full Belle data set

We report an improved measurement of D0-D0bar mixing and a search for CP violation in D0 decays to CP-even final states K+K- and pi+pi-. The measurement is based on the final Belle data sample of 976/fb. The results are y_CP=(1.11 +- 0.22 +- 0.09)% and A_Gamma=(-0.03 +- 0.20 +- 0.07)%, where the first uncertainty is statistical and the second is systematic.Comment: 8 pages, 5 figures; submitted to Phys. Lett.

Study of X(3872) in BB meson decays

We present results on the X(3872), produced in $B^+ \to X(3872) K^+$ and $B^0 \to X(3872) K^0_S$ decays where $X(3872) \to J/\psi \pi^+ \pi^-$. We report the first statistically significant observation of $B^0 \to X(3872) K^0_S$ and measure the ratio of branching fractions to be $\frac{{\cal B}(B^0 \to X(3872)K^0)} {{\cal B}(B^+ \to X(3872)K^+)} = 0.82 \pm 0.22 \pm 0.05$, consistent with unity. The mass difference between the X(3872) states produced in $B^+$ and $B^0$ decay is found to be $\delta M \equiv M_{XK^+} - M_{XK^0} = (+0.18 \pm 0.89 \pm 0.26)$ MeV/$c^2$, consistent with zero. In addition, we search for the X(3872) in the decay $B^0 \to X(3872)K^+\pi^-$, $X(3872) \to J/\psi \pi^+ \pi^-$. We measure ${\cal B}(B^0 \to X(3872) (K^+ \pi^-)_{NR}) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (8.1 \pm 2.0 ^{+1.1}_{-1.4})\times 10^{-6}$ and we set the 90% C.L. limit, ${\cal B}(B^0 \to X(3872)K^{*}(892)^0) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) < 3.4 \times 10^{-6}$. The analysis is based on a 605 fb$^{-1}$ data sample collected at the $\Upsilon(4S)$ with the Belle detector at the KEKB collider.Comment: 10 pages, 5 figures, Contributed to the 34th International Conference On High Energy Physics (ICHEP 2008

Hadronic Mass Moments in B -> X_c l nu Decays

We report measurements of the first and second moments of the hadronic invariant mass squared distribution, and )^2>, in B -> X_c l nu decays for minimum lepton momenta ranging from 0.7 to 1.5 GeV/c in the B meson rest frame. The measurement uses BBbar events in which the hadronic decay of one B meson is fully reconstructed and the semileptonic decay of the other B is inferred from the presence of an identified lepton. These results are obtained from a 140 fb^-1 data sample collected near the Y(4S) resonance with the Belle detector at the KEKB asymmetric energy e^+e^- collider.Comment: 9 pages, 2 figures, 4 tables, contributed to Lepton Photon and EPS 200

Measurement of D0 -> pilnu (Klnu) and their form factors

Using a data sample of 282 1/fb collected by the Belle experiment at the KEKB e+e- collider, we study D0 -> pilnu and D0 -> Klnu decays (l = mu,e) in e+e- annihilation. We identify D* -> D0pi decays by using the mass of the system recoiling against a fully reconstructed tag-side D* or D meson, allowing for additional primary mesons from fragmentation. Using a novel global reconstruction method that provides very good resolution in neutrino momentum and in q^2 = (p_l+p_nu)^2, we reconstructed D0 -> pilnu and D0 -> Klnu decays. From these events we measured the branching fraction ratios BR(D0 -> pienu)/BR(D0 -> Kenu) = 0.0809 +- 0.0080 +- 0.0032$ and BR(D0 -> pimunu)/BR(D0 -> Kmunu) = 0.0677 +- 0.0078 +- 0.0047, and the semileptonic form factor ratio f+(D0 -> pilnu})^2/f+(D0 -> Klnu})^2|Vcd|^2/|Vcs|^2|_{q^2=0} = 0.041 +- 0.003 +- 0.004, where the errors are statistical and systematic, respectively.Comment: 20 pages, 8 figures; corrected form factor rati

Abstracting Probabilistic Models: A Logical Perspective

Abstraction is a powerful idea widely used in science, to model, reason and explain the behavior of systems in a more tractable search space, by omitting irrelevant details. While notions of abstraction have matured for deterministic systems, the case for abstracting probabilistic models is not yet fully understood. In this paper, we provide a semantical framework for analyzing such abstractions from first principles. We develop the framework in a general way, allowing for expressive languages, including logic-based ones that admit relational and hierarchical constructs with stochastic primitives. We motivate a definition of consistency between a high-level model and its low-level counterpart, but also treat the case when the high-level model is missing critical information present in the low-level model. We prove properties of abstractions, both at the level of the parameter as well as the structure of the models. We conclude with some observations about how abstractions can be derived automatically.Comment: In AAAI Workshop: Statistical Relational Artificial Intelligence, 2020. (This is the extended version.

Moments of the Hadronic Mass Spectrum in Inclusive Semileptonic B Decays at Belle

We report a measurement of the first and second moment of the hadronic mass distribution M_X in B -> X_c l nu decays for lepton threshold momenta ranging from 0.9 to 1.6 GeV/c in the center of mass frame. The measurement uses B Bbar events in which the hadronic decay of one B meson is fully reconstructed and a charged lepton from the decay of the other B meson is identified. These results are obtained from a 140 fb^-1 data sample collected near the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider.Comment: 9 pages, 3 figures, submitted to ICHEP2004, Beijing, Chin

Measurement of the angle \phi_3 with Dalitz analysis of three-body D^0 decay from B\to D^0 K process

A new method to measure the angle $\phi_3$ of the CKM unitarity triangle using a Dalitz analysis of the three-body decay of the $D^0$ meson from the $B\to D^0 K$ process has been introduced recently. The method employs the interference between $D^0$ and $\bar{D^0}$ to extract both the weak and strong phases. We present a study of statistical and systematic errors of this method using Monte Carlo simulation. A fit of the $D^0$ Dalitz distribution has been performed based on a 140 fb$^{-1}$ sample collected by the Belle detector. We observe the indication of a CP asymmetry with the significance of 2.4 standard deviations. The 90% confidence interval obtained for the $\phi_3$ value is $61^{\circ}<\phi_3<142^{\circ}$.Comment: 25 pages, 14 figures, contributed paper at Lepton Photon 200

Moments of the Electron Energy Spectrum in B --> X_c l \nu decays at Belle

We report a measurement of the inclusive electron energy spectrum for charmed semileptonic decays of B mesons in a 140 fb^-1 data sample collected on the Upsilon(4S) resonance, with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. We determine the first, second and third moments of the electron energy spectrum for threshold values of the electron energy between 0.4 and 1.5 GeV.Comment: 13 pages, 3 figures, 6 tables, contributed to HEP2005 International Europhysics Conference on High Energy Physic

Observation of h_b(1P)->eta_b(1S)gamma

We report the first observation of the radiative transition h_b(1P)->eta_b(1S)gamma, where the h_b(1P) is produced in Upsilon(5S)->h_b(1P)pi+pi- dipion transitions. We measure the eta_b(1S) mass to be (9401.0+-1.9+1.4-2.4)MeV/c^2 with a width of (12.4+5.5-4.6+11.5-3.4)MeV and a decay branching fraction of BF[h_b(1P)->eta_b(1S)gamma]=(49.8+-6.8+10.9-5.2)%. The measured eta_b(1S) mass corresponds to a hyperfine splitting of (59.3+-1.9+2.4-1.4)MeV/c^2. This value deviates significantly from the current world average obtained from measurements of Upsilon(3S)->eta_b(1S)gamma and Upsilon(2S)->eta_b(1S)gamma reactions. We also report updated results for the h_b(1P) mass (9899.0+-0.4+-1.0)MeV/c^2 and its hyperfine splitting (0.8+-1.1)MeV/c^2. These measurements are performed using a 121.4fb^-1 data sample collected at the peak of the Upsilon(5S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider.Comment: Prepared for International Workshop on Heavy Quarkonium 2011 (QWG 2011), GSI, Darmstadt, Germany, 4-7 Oct 201

Measurement of the branching fractions for B0→Ds∗+π−B^0 \to D_s^{*+}\pi^- and B0→Ds∗−K+B^0 \to D_s^{*-}K^+ decays

We present a study of $B^0 \to D_s^{*+}\pi^-$ and $B^0 \to D_s^{*-}K^+$ decays based on a sample of $657 \times 10^6$ $B\bar{B}$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. We measure the branching fractions to be $\mathcal{B}(B^0 \to D_s^{*+} \pi^-) = (1.75 \pm 0.34 \pm 0.17 \pm 0.11) \times 10^{-5}$ and $\mathcal{B}(B^0 \to D_s^{*-} K^+) = (2.02 \pm 0.33 \pm 0.18 \pm 0.13) \times 10^{-5}, with significances of 6.1 and 8.0 standard deviations, respectively. The first uncertainty is statistical, the second is due to the experimental systematics, and the third is from uncertainties in the$D_s^+$decay branching fractions. From our measurements, we obtain the most precise determination so far of$R_{D^*\pi}$, where$R_{D^*\pi}$is the ratio between amplitudes of the doubly Cabibbo-suppressed decay$B^0 \to D^{*+}\pi^-$and the Cabibbo favored$B^0 \to D^{*-}\pi^+$ decay.Comment: 6 pages, 2 figures, 2 tables. Submitted to PRD (RC