4,766 research outputs found
Precision Measurements of the Semileptonic Charm Decays and
We investigate the decays and ,
where is or , using approximately 7 of data
collected with the CLEO III detector. We find . Fits to
the kinematic distributions of the data provide parameters describing the form
factor of each mode. Combining the form factor results and gives
.Comment: 5 pages, 2 figures, talk given at DPF'04, UC Riverside, C
Final State Interactions in Decays of the Exotic Meson
We analyze the role of final state interactions in decay of the lighest
exotic meson, with \pi b_{1}\pi\rho\pi_{1}\pi_1(1600)\omega\pi_{1}\pi\rho$ mode cannot be generated through level
mixing.Comment: 7 pages, 11 figure
Turbulent thermal diffusion of aerosols in geophysics and laboratory experiments
We discuss a new phenomenon of turbulent thermal diffusion associated with
turbulent transport of aerosols in the atmosphere and in laboratory
experiments. The essence of this phenomenon is the appearance of a nondiffusive
mean flux of particles in the direction of the mean heat flux, which results in
the formation of large-scale inhomogeneities in the spatial distribution of
aerosols that accumulate in regions of minimum mean temperature of the
surrounding fluid. This effect of turbulent thermal diffusion was detected
experimentally. In experiments turbulence was generated by two oscillating
grids in two directions of the imposed vertical mean temperature gradient. We
used Particle Image Velocimetry to determine the turbulent velocity field, and
an Image Processing Technique based on an analysis of the intensity of Mie
scattering to determine the spatial distribution of aerosols. Analysis of the
intensity of laser light Mie scattering by aerosols showed that aerosols
accumulate in the vicinity of the minimum mean temperature due to the effect of
turbulent thermal diffusion. Geophysical applications of the obtained results
are discussed.Comment: 9 pages, 6 figures, revtex
Survival before annihilation in Psi-prime decays
We extend the simple scenario for decays suggested a few years ago.
The pair in the does not annihilate directly into three
gluons but rather survives before annihilating. An interesting prediction is
that a large fraction of all decays could originate from the channel which we urge experimentalists to identify. Our model
solves the problem of the apparent hadronic excess in decays as well as
the puzzle since, in our view, the two-body decays of the are
naturally of electromagnetic origin. Further tests of this picture are
proposed, e.g. .Comment: 6 pages, no figur
decays
Effective chiral theory of mesons is applied to study the four decay modes of
. Theoretical values of the branching ratios are in
agreement with the data. The theory predicts that the resonance plays a
dominant role in these decays. There is no new parameter in this study.Comment: 12 pages and one figur
The Impact of Measurements at Intermediate Energies on the Parameters of the Standard Model
We discuss the impact of precision measurements of in the center-of-mass range between 3 and 12 GeV, including
improvements in the electronic widths of the narrow charmonium and bottonium
resonances, on the determination of parameters of the Standard Model. In
particular we discuss the impact of potential improvements on the extraction of
the strong coupling constant , on the evaluation of the hadronic
contributions to the electromagnetic coupling , and the
determination of the charm and bottom quark masses.Comment: 8 page
Forward dispersion relations and Roy equations in pi-pi scattering
We review results of an analysis of pipi interactions in S, P and D waves for
two-pion effective mass from threshold to about 1.4 GeV. In particular we show
a recent improvement of this analysis above the K anti-K threshold using more
data for phase shifts and including the S0 wave inelasticity from pipi -> K
anti-K. In addition, we have improved the fit to the f2(1270) resonance and
used a more flexible P wave parametrization above the K anti-K threshold and
included an estimation of the D2 wave inelasticity. The better accuracy thus
achieved also required a refinement of the Regge analysis above 1.42 GeV. We
have checked that the pipi scattering amplitudes obtained in this approach
satisfy remarkably well forward dispersion relations and Roy's equations.Comment: 6 pages, invited talk to the IV International Conference on Quarks
and Nuclear Physics QNP06, Madrid 5th-10th June 200
Light scalars as tetraquarks or two-meson states from large Nc and unitarized Chiral Perturbation Theory
By means of unitarized Chiral Perturbation Theory it is possible to obtain a
remarkable description of meson-meson scattering amplitudes up to 1.2 GeV, and
generate poles associated to scalar and vector resonances. Since Chiral
Perturbation Theory is the QCD low energy effective theory, it is possible then
to study its large Nc limit where qqbar states are easily identified. The
vectors thus generated follow closely a qqbar behavior, whereas the light
scalar poles follow the large Nc behavior expected for a dominant tetraquark or
two-meson structure.Comment: Invited Brief Report to appear in Modern Physcis Letters A. 15 page
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