1,941 research outputs found
Study light scalar meson property from heavy meson decays
In the SU(3) symmetry limit, the ratio is
equal to 1 if the scalar mesons are states, while it is 3 if these
mesons are tentraquark states. This ratio provides a model-independent way to
distinguish the descriptions for light scalar mesons . It also applies to the
and decays. The SU(3)
symmetry breaking effect is found to be under control, which will not spoil our
method. The branching fractions of the ,
and decays roughly have the order ,
and , respectively. The B factory experiments and ongoing
BEPC-II experiments are able to measure these channels and accordingly to
provide the detailed information of the scalar meson inner structure.Comment: 5 pages, talk given at 45th Rencontres de Moriond QCD and High Energy
Interactions, March 2010, La Thuile and XIII International Conference on
Hadron Spectroscopy, Florida, 200
Lepton flavor violating processes in unparticle physics
We study the virtual effects of unparticle physics in the lepton flavor
violating processes and scattering, where
denotes the pseudoscalar mesons: and
denote two different lepton flavors. For the decay of , there
is no constraint from the current experimental upper bounds on the vector
unparticle coupling with leptons. The constraint on the coupling constant
between scalar unparticle field and leptons is sensitive to the scaling
dimension of the unparticle . For the scattering process , there is only constraint from experiments on the vector unparticle
couplings with leptons but no constraint on the scalar unparticle. We study the
dependence of the cross section of with different values of
. If , the cross section is independent on the
center mass energy. For , the cross section increases with
.Comment: 8 pages, revtex4,with 2 figures, to appear in Phys. Rev.
to P-Wave Charmonia Transitions in Covariant Light-Front Approach
In the covariant light-front quark model, we investigate the form factors. The form factors are evaluated in space-like
kinematic region and are recasted to the physical region by adopting the
exponential parametrization. We also study the semileptonic decays and
find that branching fractions for the decays have the order while branching fractions for
are suppressed by one order. These
predictions will be tested at the forthcoming hadron colliders.Comment: 13 pages, 1 figure, published in Phys. Rev.
Transition Form Factors in the PQCD approach
Under two different scenarios for the light scalar mesons, we investigate the
transition form factors of mesons decay into a scalar meson in the
perturbative QCD approach. In the large recoiling region, the form factors are
dominated by the short-distance dynamics and can be calculated using
perturbation theory. We adopt the dipole parametrization to recast the
dependence of the form factors. Since the decay constants defined by the scalar
current are large, our predictions on the form factors are much larger
than the transitions, especially in the second scenario. Contributions
from various light-cone distribution amplitudes (LCDAs) are elaborated and we
find that the twist-3 LCDAs provide more than a half contributions to the form
factors. The two terms of the twist-2 LCDAs give destructive contributions in
the first scenario while they give constructive contributions in the second
scenario. With the form factors, we also predict the decay width and branching
ratios of the semileptonic and decays. The
branching ratios of channels are found to have the order of
while those of have the order of . These
predictions can be tested by the future experiments.Comment: 20 pages, 31 figure
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