159 research outputs found
Non-Leptonic Decays of B Mesons and Strong Coupling Constants
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
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 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 in the decay as well as the
ratio~. 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
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
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
An examination of leptons in events tagged by reconstructed
decays yields semileptonic branching fractions of for charged and for neutral mesons.
This is the first measurement for charged . Assuming equality of the charged
and neutral semileptonic widths, the ratio 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
Using data collected with the CLEO~II detector, we have observed the
isospin-violating decay . The decay rate for this mode,
relative to the dominant radiative decay, is found to be .Comment: 8 page uuencoded postscript file, also available through
http://w4.lns.cornell.edu/public/CLN
Measurements of the Ratios and
Using the CLEO~II detector we measure , and .
We find the vector to pseudoscalar ratio, , which is similar to the
ratio found in non strange decays.Comment: 11 page uuencoded postscript file, postscript file also available
through http://w4.lns.cornell.edu/public/CLN
Search for the Decay
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 Branching Fraction
Using the angular correlation between the emitted in a decay and the emitted in the subsequent decay, we have measured the branching fraction for the
inclusive semi-electronic decay of the 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 of 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 of the inclusive rate.Comment: Latex file, 33pages, 4 figures Submitted to PR
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