472 research outputs found
Exclusive semileptonic decays of B mesons into light mesons in the relativistic quark model
The exclusive semileptonic decays are studied in the
framework of the relativistic quark model based on the quasipotential approach
in quantum field theory. The large recoil momentum of the final
meson allows for the expansion of the decay form factors at in the
inverse powers of -quark mass. This considerably simplifies the analysis of
these decays. The expansion is carried out up to the first order. It is
found that the -dependence of the axial form factor is different
from the -behaviour of other form factors. We find s and
s. The relation between semileptonic and rare radiative
-decays is discussed.Comment: 11 pages, Latex, 3 figure
Semileptonic decays of heavy baryons in the relativistic quark model
Semileptonic decays of heavy baryons consisting of one heavy (Q=b,c) and two
light (q=u,d,s) quarks are considered in the heavy-quark--light-diquark
approximation. The relativistic quasipotential equation is used for obtaining
masses and wave functions of both diquarks and baryons within the constituent
quark model. The weak transition matrix elements are expressed through the
overlap integrals of the baryon wave functions. The Isgur-Wise functions are
determined in the whole accessible kinematic range. The exclusive semileptonic
decay rates and different asymmetries are calculated with applying the heavy
quark 1/m_Q expansion. The evaluated Lambda_b -> Lambda_c l nu decay rate
agrees with its experimental value.Comment: 22 pages, 9 figure
Radiative M1-decays of heavy-light mesons in the relativistic quark model
Radiative magnetic dipole decays of heavy-light vector mesons into
pseudoscalar mesons V -> P\gamma are considered within the relativistic quark
model. The light quark is treated completely relativistically, while for the
heavy quark the 1/m_Q expansion is used. It is found that relativistic effects
result in a significant reduction of decay rates. Comparison with previous
predictions and recent experimental data is presented.Comment: 11 pages, 2 figures, few comments added, version to appear in Phys.
Lett.
Rare radiative B decay to the orbitally excited K_2^*(1430) meson
The exclusive rare radiative B meson decay to the orbitally excited tensor
K_2^*(1430) meson is investigated in the framework of the relativistic quark
model based on the quasipotential approach in quantum field theory. The
calculated branching ratio BR(B --> K_2^*(1430)\gamma)=(1.7\pm 0.6)\times
10^{-5} as well as the ratio BR(B --> K_2^*(1430)\gamma)/BR(B -->
K^*(892)\gamma)=0.38\pm 0.08 is found in a good agreement with recent
experimental data from CLEO.Comment: 10 pages, RevTe
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
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