1,625 research outputs found
Determination of mixing angle from QCD sum rules
By assuming that the and mesons are mixed states of the
two-quark - tetraquark, the mixing angle between them is estimated within QCD
sum rules method, and it is obtained that the mixing angle is . Our prediction on mixing angle can be checked in further
experiments which can shed light on choosing the "right" structure of and
mesons
The mass and residues of radially and orbitally excited doubly heavy baryons in QCD
The mass and residues of the first radial and orbital excitations of
baryons containing two heavy quarks (b or c) are calculated
within the QCD sum rules method. In calculations, the general forms of the
interpolating currents with symmetric and anti-symmetric forms with respect to
the exchange of heavy quarks have been used. Our results on the spectroscopic
parameters of doubly heavy baryons are compared with the predictions of other
theoretical approaches
Are the new excited baryons negative parity states?
We calculate the mass and residue of the newly observed and
states with quantum numbers and
within QCD sum rules. Our predictions on masses are in good
agreement with the experimental results.Comment: 12 pages, 7 figures; typos corrected, appendix is adde
Properties of excited states in QCD
The mass and leptonic decay constants of recently observed two new excited
states at LHC are studied within the QCD sum rules. Considering the
contributions of the ground and radially excited states, the mass and residues
of the excited states of pseudoscalar and vector mesons are calculated in the
framework of two different approaches of the QCD sum rules, namely, linear
combinations of the corresponding sum rules and its derivatives as well as QCD
sum rules with the incorporation of the least square fitting method. The
obtained results on mass and
are in good agreement with the
experimental data. Our predictions for the decay constants of these states are:
and , which can be checked at future experiments to be conducted at
the LHC. Comparison of our results with the predictions of the other approaches
on mass and residues is also presented.Comment: 11 pages, 4 figures Misprints are corrected and reference list has
been update
Light-Cone Distribution Amplitudes of Light Tensor Mesons in QCD
We present a study for two-quark light-cone distribution amplitudes for the
light tensor meson states with quantum number . Because
of the G-parity, the chiral-even two-quark light-cone distribution amplitudes
of this tensor meson are antisymmetric under the interchange of momentum
fractions of the quark and antiquark in the SU(3) limit, while the chiral-odd
ones are symmetric. The asymptotic leading-twist LCDAs with the strange quark
mass correction are shown. We estimate the relevant parameters, the decay
constants and , and first Gegenbauer moment , by
using the QCD sum rule method. These parameters play a central role in the
investigation of meson decaying into the tensor mesons.Comment: 18 pages, 3 Figure
Light-Cone Distribution Amplitudes of Light Tensor Mesons in QCD
We present a study for two-quark light-cone distribution amplitudes for the
light tensor meson states with quantum number . Because
of the G-parity, the chiral-even two-quark light-cone distribution amplitudes
of this tensor meson are antisymmetric under the interchange of momentum
fractions of the quark and antiquark in the SU(3) limit, while the chiral-odd
ones are symmetric. The asymptotic leading-twist LCDAs with the strange quark
mass correction are shown. We estimate the relevant parameters, the decay
constants and , and first Gegenbauer moment , by
using the QCD sum rule method. These parameters play a central role in the
investigation of meson decaying into the tensor mesons.Comment: 18 pages, 3 Figure
Constraints on Dark Photon from Neutrino-Electron Scattering Experiments
A possible manifestation of an additional light gauge boson , named
as Dark Photon, associated with a group is studied in neutrino
electron scattering experiments. The exclusion plot on the coupling constant
and the dark photon mass is obtained. It is shown
that contributions of interference term between the dark photon and the
Standard Model are important. The interference effects are studied and compared
with for data sets from TEXONO, GEMMA, BOREXINO, LSND as well as CHARM II
experiments. Our results provide more stringent bounds to some regions of
parameter space.Comment: 22 pages, 6 figures, 2 tables, text improved, fig.6 updated,
references adde
Charmed baryon and decays in light cone sum rules
The semileptonic and non-leptonic
, decays of
charmed baryon are studied within the light cone sum rules. The form
factors responsible for transitions are calculated using
the distribution amplitudes of baryon. With the obtained form
factors, the branching ratios of ,
, and decays are estimated. The results are compared with Belle data as well
as the findings of the other approaches
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