10,460 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
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
Exclusive B -> K^* l^+ l^- decay with polarized K^* and new physics effects
Using the most general, model independent effective Hamiltonian, the
branching ratio of the (B -> K^* l^+ l^-) decay, when K^* meson is
longitudinally or transversally polarized, is presented. The dependence of the
branching ratio on the new Wilson coefficients, when K^* meson is polarized, is
studied. It is observed that the branching ratio is very sensitive to the
vector and tensor type interactions, which will be useful in search of new
physics beyond the Standard Model.Comment: 13 pp, 6 figures (postscript formatted), LaTex formatte
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 transitions of decuplet to octet baryons and pseudoscalar mesons
The strong coupling constants of light pseudoscalar , and
mesons with decuplet--octet baryons are studied within light cone QCD sum
rules, where symmetry breaking effects are taken into account. It is
obtained that all coupling constants under the consideration are described by
only one universal function even if symmetry breaking effects are
switched into the game.Comment: 21 Pages, 2 Figures and 3 Table
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
General analysis of time evolution of decay spectrum in B^0 -> pi^+ pi^- l^+ l^-
Using the general, model independent form of effective Hamiltonian, the decay
spectrum of B^0 -> pi^+ pi^- l^+ l^- decay is studied. The sensitivity of
experimentally measurable asymmetries to the new Wilson coefficients and time
is studied. It is observed that different asymmetries are sensitive to the new
Wilson coefficients and they can serve as an efficient tool for establishing
new physics beyond SM.Comment: 15 pp, 4 figures (postscript formatted), LaTex formatte
Heavy tensor mesons in QCD
The masses and decay constants of the ground state heavy
tensor mesons are calculated in the framework of the QCD sum rules approach.
The obtained results on the masses are in good consistency with the
experimental values. Our predictions on the decay constants can be verified in
the future experiments.Comment: 7 Pages and one Tabl
General analysis of lepton polarizations in rare B -> K^* l^+ l^- decay beyond the standard model
The general analysis of lepton polarization asymmetries in rare B -> K^* l^+
l^- decay is investigated. Using the most general, model independent effective
Hamiltonian, the general expressions of the longitudinal, normal and
transversal polarization asymmetries for l^- and l^+ and combinations of them
are presented. The dependence of lepton polarizations and their combinations on
new Wilson coefficients are studied in detail. Our analysis shows that the
lepton polarization asymmetries are very sensitive to the scalar and tensor
type interactions, which will be very useful in looking for new physics beyond
the standard model.Comment: 29 pp, 15 figure
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