1,752 research outputs found
New analysis of semileptonic B decays in the relativistic quark model
We present the new analysis of the semileptonic B decays in the framework of
the relativistic quark model based on the quasipotential approach. Decays both
to heavy D^{(*)} and light \pi(\rho) mesons are considered. All relativistic
effects are systematically taken into account including contributions of the
negative-energy states and the wave function transformation from the rest to
moving reference frame. For heavy-to-heavy transitions the heavy quark
expansion is applied. Leading and subleading Isgur-Wise functions are
determined as the overlap integrals of initial and final meson wave functions.
For heavy-to-light transitions the explicit relativistic expressions are used
to determine the dependence of the form factors on the momentum transfer
squared. Such treatment significantly reduces theoretical uncertainties and
increases reliability of obtained predictions. All results for form factors,
partial and total decay rates agree well with recent experimental data and
unquenched lattice calculations. From this comparison we find the following
values of the Cabibbo-Kobayashi-Maskawa matrix elements:
|V_{cb}|=(3.85\pm0.15\pm 0.20)*10^{-2} and
|V_{ub}|=(3.82\pm0.20\pm0.20)*10^{-3}, where the first error is experimental
and the second one is theoretical.Comment: 25 pages, 11 figure
Heavy baryon spectroscopy
Masses of heavy baryons are calculated in the relativistic quark-diquark
picture. Obtained results are in good agreement with available experimental
data including recent measurements by the LHCb Collaboration. Possible quantum
numbers of excited heavy baryon states are discussed.Comment: 10 pages, 1 figure, talk at XXIV International Baldin Seminar on High
Energy Physics Problems, Sep 17-22, 2018, Dubna, Russi
Rare decays in the relativistic quark model
The branchings fractions of the rare decays are calculated in the
framework of the QCD-motivated relativistic quark model. The form factors of
the weak transitions to light mesons are expressed through the overlap
integral of the initial and final meson wave functions in the whole accessible
kinematical range. Explicit determination of the momentum transfer dependence
of the form factors without additional model assumptions and extrapolations
significantly improve the reliability of the obtained results. The approximate
analytical form of the form factors is given in order to simplify the
comparison with other predictions and experiment. The calculated form factors
are applied for the investigations of the rare semileptonic, radiative and
nonleptonic decays. The factorization approximation is used for the
description of the nonleptonic decays. All results agree well with available
experimental data.Comment: 23 pages, 10 figure
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