6,809 research outputs found

    QCD Interactions of Heavy Mesons with Pions by Light-Cone Sum Rules

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    Light-cone QCD sum rules are employed to compute the strong coupling constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and (B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ doublets. The couplings are calculated both for finite values of the heavy quark mass and in the infinite heavy quark mass limit, deriving sum rules for m_Q \to \infty.Comment: Latex, 23 pages, 6 figures. Revised version to appear in Z. Phys.

    On three-body B0→D∗−D(∗)0K+B^0 \to D^{*-} D^{(*)0} K^+ decays and couplings of heavy mesons to light pseudoscalar mesons

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    We analyze the decay modes B0→D∗−D0K+B^0 \to D^{*-} D^0 K^+ and B0→D∗−D∗0K+B^0 \to D^{*-} D^{*0} K^+ and, using the available experimental data, we find bounds for the constants g and h describing the strong coupling of heavy mesons to light pseudoscalar mesons. Both the decay channels are dominated by broad L=1 charm resonances; the dominance is effective also in B0→D−D0K+B^0 \to D^{-} D^0 K^+ and B0→D−D∗0K+B^0 \to D^{-} D^{*0} K^+.Comment: LaTex, 16 pages, 5 figure

    B→Kη(′)γB\to K \eta^{(\prime)} \gamma decays in the standard model and in scenarios with universal extra dimensions

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    We study the radiative B→Kη(′)γB \to K \eta^{(\prime)} \gamma decays, which are important to investigate CP violation, and are also relevant to assess the role of the exclusive modes induced by the b→sγb \to s \gamma transition to saturate the inclusive B→XsγB \to X_s \gamma decay rate. Moreover, these channels do not display the same hierarchy as B→Kη(′)B \to K \eta^{(\prime)} modes, for which the decay into η′\eta^\prime is enhanced with respect to one into η\eta. The three-body radiative decays reverse the role: we find that this experimentally observed behavior (although affected by a large uncertainty in the case of the η′\eta^\prime) is reproduced in the theoretical analysis. We compute a B∗→KB^* \to K form factor, needed for this study, using light cone QCD sum rules, and discuss a relation expected to hold in the large energy limit for the light meson. Finally, we examine B→KηγB\to K \eta \gamma in two extensions of the standard model with universal extra dimensions, to investigate the sensitivity of this rare mode to such a kind of new physics effects.Comment: RevTeX, 17 pages, 7 figures. High resolution figures available upon request. Matches the published versio

    A City-Scale ITS-G5 Network for Next-Generation Intelligent Transportation Systems: Design Insights and Challenges

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    As we move towards autonomous vehicles, a reliable Vehicle-to-Everything (V2X) communication framework becomes of paramount importance. In this paper we present the development and the performance evaluation of a real-world vehicular networking testbed. Our testbed, deployed in the heart of the City of Bristol, UK, is able to exchange sensor data in a V2X manner. We will describe the testbed architecture and its operational modes. Then, we will provide some insight pertaining the firmware operating on the network devices. The system performance has been evaluated under a series of large-scale field trials, which have proven how our solution represents a low-cost high-quality framework for V2X communications. Our system managed to achieve high packet delivery ratios under different scenarios (urban, rural, highway) and for different locations around the city. We have also identified the instability of the packet transmission rate while using single-core devices, and we present some future directions that will address that.Comment: Accepted for publication to AdHoc-Now 201

    Aspectos a tener en cuenta en la endodoncia en el adulto mayor

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    Fil: Fazio, P.. Universidad Nacional de Cuyo. Facultad de Odontologí

    Primary commodity prices: co-movements, common factors and fundamentals

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    The behavior of commodities is critical for developing and developed countries alike. This paper contributes to the empirical evidence on the co-movement and determinants of commodity prices. Using nonstationary panel methods, we document a statistically significant degree of co-movement due to a common factor. Within a Factor Augmented VAR approach, real interest rate and uncertainty, as postulated by a simple asset pricing model, are both found to be negatively related to this common factor. This evidence is robust to the inclusion of demand and supply shocks, which both positively impact on the co-movement of commodity prices.Commodity Prices, Panel Estimation, Factor Models
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