158 research outputs found

    Non-Leptonic Decays of B Mesons and Strong Coupling Constants

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    Non-leptonic decays of B mesons into two mesons or meson resonances are studied on the basis of two versions of simple pole-dominance models involving scalar, vector, pseudoscalar and axial-vector poles. The results are compared with those obtained from the usual factorization model and used to obtain information on strong coupling constants between B meson and one light or one charmed meson, respectively. These coupling constants are compared to results from various QCD sum rule calculations.Comment: Latex file 35 pages, including 3 figure

    Relativistic Description of Exclusive Semileptonic Decays of Heavy Mesons

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    Using quasipotential approach, we have studied exclusive semileptonic decays of heavy mesons with the account of relativistic effects. Due to more complete relativistic description of the ss quark more precise expressions for semileptonic form factors are obtained. Various differential distributions in exclusive semileptonic decays of heavy mesons are calculated. It is argued that consistent account of relativistic effects and HQET motivated choice of the parameters of quark-antiquark potential allow to get reliable value for the ratio A2(0)/A1(0)A_2(0)/A_1(0) in the D→K∗lνlD\to K^*l\nu_l decay as well as the ratio~Γ(D→K∗lνl)/Γ(D→Klνl)\Gamma(D\to K^*l\nu_l)/\Gamma(D\to Kl\nu_l). All calculated branching ratios are in accord with available experimental data.Comment: 18 pages, LATEX, 2 figures inclosed + 4 Postscript figure

    Measurements of B→D_s^+X decays

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    This paper describes new measurements from CLEO of the inclusive B→D_s^+X branching fraction as well as the B^+→D_s^((*)+)D^((*)0) and B^0→D_s^((*)+)D^((*)-) branching fractions. The inclusive branching fraction is B(B→D_s^+X)=(12.11±0.39±0.88±1.38)% where the first error is statistical, the second is the systematic error, and the third is the error due to the uncertainty in the D_s^+→φπ^+ branching fraction. The branching fractions for the B→D_s^((*)+)D^(*) modes are found to be between 0.9% and 2.4% and are significantly more precise than previous measurements. The sum of the B→D_s^((*)+)D^(*) branching fractions is consistent with the results of fits to the inclusive D_s^+ momentum spectrum. Factorization is used to arrive at a value for f_D_s, the D_s^+ decay constant

    Local Phenomena Shape Backyard Soil Metabolite Composition

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    Soil covers most of Earth’s continental surface and is fundamental to life-sustaining processes such as agriculture. Given its rich biodiversity, soil is also a major source for natural product drug discovery from soil microorganisms. However, the study of the soil small molecule profile has been challenging due to the complexity and heterogeneity of this matrix. In this study, we implemented high-resolution liquid chromatography–tandem mass spectrometry and large-scale data analysis tools such as molecular networking to characterize the relative contributions of city, state and regional processes on backyard soil metabolite composition, in 188 soil samples collected from 14 USA States, representing five USA climate regions. We observed that region, state and city of collection all influence the overall soil metabolite profile. However, many metabolites were only detected in unique sites, indicating that uniquely local phenomena also influence the backyard soil environment, with both human-derived and naturally-produced (plant-derived, microbially-derived) metabolites identified. Overall, these findings are helping to define the processes that shape the backyard soil metabolite composition, while also highlighting the need for expanded metabolomic studies of this complex environment.This research was supported by start-up funds from the University of Oklahoma (to L.-I.M.). Open Access fees paid for in whole or in part by the University of Oklahoma Libraries.Ye

    Semileptonic Branching Fraction of Charged and Neutral B Mesons

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    An examination of leptons in Υ(4S){\Upsilon (4S)} events tagged by reconstructed BB decays yields semileptonic branching fractions of b−=(10.1±1.8±1.4)%b_-=(10.1 \pm 1.8\pm 1.4)\% for charged and b0=(10.9±0.7±1.1)%b_0=(10.9 \pm 0.7\pm 1.1)\% for neutral BB mesons. This is the first measurement for charged BB. Assuming equality of the charged and neutral semileptonic widths, the ratio b−/b0=0.93±0.18±0.12b_-/b_0=0.93 \pm 0.18 \pm 0.12 is equivalent to the ratio of lifetimes. A postscript version is available through World-Wide-Web in http://w4.lns.cornell.edu/public/CLNS/1994Comment: 9 pages (in REVTEX format) Preprint CLNS94-1286, CLEO 94-1

    Observation of the Isospin-Violating Decay Ds∗+→Ds+π0D_s^{*+}\to D_s^+\pi^0

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    Using data collected with the CLEO~II detector, we have observed the isospin-violating decay Ds∗+→Ds+π0D_s^{*+}\to D_s^+\pi^0. The decay rate for this mode, relative to the dominant radiative decay, is found to be Γ(Ds∗+→Ds+π0)/Γ(Ds∗+→Ds+γ)=0.062−0.018+0.020±0.022\Gamma(D_s^{*+}\to D_s^+\pi^0)/\Gamma(D_s^{*+}\to D_s^+\gamma)= 0.062^{+0.020}_{-0.018}\pm0.022.Comment: 8 page uuencoded postscript file, also available through http://w4.lns.cornell.edu/public/CLN

    Measurements of the Ratios B(Ds+→ηℓ+ν)/B(Ds+→ϕℓ+ν){\cal B}(D_s^+\to \eta\ell^+\nu)/{\cal B}(D_s^+\to \phi\ell^+\nu) and B(Ds+→η′ℓ+ν)/B(Ds+→ϕℓ+ν){\cal B}(D_s^+\to \eta'\ell^+\nu)/{\cal B}(D_s^+\to \phi\ell^+\nu)

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    Using the CLEO~II detector we measure B(Ds+→ηe+ν)/B(Ds+→ϕe+ν)=1.24±0.12±0.15{\cal B}(D_s^+\to \eta e^+\nu)/{\cal B}(D_s^+\to \phi e^+\nu) =1.24\pm0.12\pm0.15, B(Ds+→η′e+ν)/B(Ds+→ϕe+ν)=0.43±0.11±0.07{\cal B}(D_s^+\to \eta' e^+\nu)/{\cal B}(D_s^+\to \phi e^+\nu) =0.43\pm0.11\pm0.07 and B(Ds+→η′e+ν)/B(Ds+→ηe+ν)=0.35±0.09±0.07{\cal B}(D_s^+\to \eta' e^+\nu)/{\cal B}(D_s^+\to \eta e^+\nu) =0.35\pm0.09\pm0.07. We find the vector to pseudoscalar ratio, B(Ds+→ϕe+ν)/B(Ds+→(η+η′)e+ν)=0.60±0.06±0.06{\cal B}(D_s^+\to \phi e^+\nu)/{\cal B}(D_s^+\to (\eta+\eta') e^+\nu) =0.60\pm0.06\pm0.06, which is similar to the ratio found in non strange DD decays.Comment: 11 page uuencoded postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Search for the Decay τ−→4pi−3π+(π0)ντ\tau^{-}\to 4pi^{-}3\pi^{+}(\pi^{0})\nu_{\tau}

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    We have searched for the decay of the tau lepton into seven charged particles and zero or one pi0. The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR) and correspond to an integrated luminosity of 4.61 fb^(-1). No evidence for a signal is found. Assuming all the charged particles are pions, we set an upper limit on the branching fraction, B(tau- -> 4pi- 3pi+ (pi0) nu_tau) < 2.4 x 10^(-6) at the 90% confidence level. This limit represents a significant improvement over the previous limit.Comment: 9 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

    Measurement of the Inclusive Semi-electronic D0D^0 Branching Fraction

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    Using the angular correlation between the π+\pi^+ emitted in a D∗+→D0π+D^{*+} \rightarrow D^0 \pi^+ decay and the e+e^+ emitted in the subsequent D0→Xe+νD^0 \rightarrow Xe^+\nu decay, we have measured the branching fraction for the inclusive semi-electronic decay of the D0D^0 meson to be: {\cal B}(D^0 \rightarrow X e^+ \nu) = [6.64 \pm 0.18 (stat.) \pm 0.29 (syst.)] \%. The result is based on 1.7 fb−1^{-1} of e+e−e^+e^- collisions recorded by the CLEO II detector located at the Cornell Electron Storage Ring (CESR). Combining the analysis presented in this paper with previous CLEO results we find, \frac{{\cal B} (D^0 \rightarrow X e^+ \nu)} {{\cal B} (D^0 \rightarrow K^- \pi^+)} = 1.684 \pm 0.056 (stat.) \pm 0.093(syst.) and \frac{{\cal B}(D\rightarrow K^-e^+\nu)} {{\cal B}(D\rightarrow Xe^+\nu)} = 0.581 \pm 0.023 (stat.) \pm 0.028(syst.). The difference between the inclusive rate and the sum of the measured exclusive branching fractions (measured at CLEO and other experiments) is (3.3±7.2)%(3.3 \pm 7.2) \% of the inclusive rate.Comment: Latex file, 33pages, 4 figures Submitted to PR
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