7,421 research outputs found
Heavy baryon--light vector meson couplings in QCD
The strong coupling constants of heavy baryons with light vector mesons are
calculated in the framework of the light cone QCD sum rules using the most
general form of the interpolating currents for the heavy baryons. It is shown
that the sextet--sextet, sextet--antitriplet and antitriplet--antitriplet
transitions are described by one invariant function for each class of
transitions. The values of the electric and magnetic coupling constants for
these transitions are obtained.Comment: 16 Pages, 4 Figures and 7 Table
B to tensor meson form factors in the perturbative QCD approach
We calculate the form factors within the framework of the
perturbative QCD approach, where denotes a light tensor meson with
. Due to the similarities between the wave functions of a vector and a
tensor meson, the factorization formulas of form factors can be
obtained from the transition through a replacement rule. As a
consequence, we find that these two sets of form factors have the same signs
and correlated -dependence behaviors. At point, the form
factors are smaller than the ones, in accordance with the experimental
data of radiative B decays. In addition, we use our results for the form
factors to explore semilteptonic decays and the branching
fractions can reach the order .Comment: 13 pages, 3 figures, 6 tables, published versio
Strong coupling constants of heavy spin--3/2 baryons with light pseudoscalar mesons
The strong coupling constants among members of the heavy spin--3/2 baryons
containing single heavy quark with light pseudoscalar mesons are calculated in
the framework of the light cone QCD sum rules. Using symmetry arguments, the
structure independent relations among different correlation functions are
obtained. It is shown that all possible transitions can be described in terms
of one universal invariant function whose explicit expression is Lorenz
structure dependent.Comment: 16 Pages, 1 figure and 1 Tabl
Double-lepton polarization asymmetries in the (B -> K l^+ l^-) decay beyond the Standard Model
General expressions for the double-lepton polarizations in the (B -> K l^+
l^-) decay are obtained, using model independent effective Hamiltonian,
including all possible interactions. Correlations between the averaged
double-lepton polarization asymmetries and the branching ratio, as well as, the
averaged single-lepton polarization asymmetry are studied. It is observed that,
study of the double-lepton polarization asymmetries can serve as a good test
for establishing new physics beyond the Standard Model.Comment: 21 pages, 18 figures, LaTeX formatte
The Strong g_B(**)BPi Coupling Constant in full QCD
To leading order in alpha_s, the leading and non-leading 1/m_b corrections to
the excited g_B^(**) meson coupling g_B^(**)BPi is calculated in the framework
of QCD spectral moment sum rules in the full theory. Our prediction is in good
agreement=20 with the light-cone QCD sum rule result.Comment: 7 pages,LaTeX formatte
Magnetic moments of baryons in QCD
The magnetic moments of the low lying, negative parity, spin-3/2 baryons are
calculated within the light cone QCD sum rules method. The contributions coming
from the positive parity, spin-3/2 baryons, as well as from the positive and
negative parity spin-1/2 baryons are eliminated by constructing combinations of
various invariant amplitudes corresponding to the coefficients of the different
Lorentz structures.Comment: 12 pages, 1 figure, LaTeX formatte
Penguin induced (B -> eta) transition form factor in light cone QCD
We calculate the penguin form factor for the (B -> eta l^+ l^-) decay. This
form factor is calculated in light cone QCD sum rules, including contributions
from wave functions up to twist-4, as well as mass corrections of the light
(eta) meson.Comment: 9 pages, 2 figures, LaTeX formatte
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