Determination of f0−a00f_0 - a_0^0 mixing angle from QCD sum rules

By assuming that the $f_0$ and $a_0^0$ 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 $(6.03 \pm 0.08)^\circ$. Our prediction on mixing angle can be checked in further experiments which can shed light on choosing the "right" structure of $f_0$ and $a_0^0$ 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 $J=\frac{1}{2}$ 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 Ωc\Omega_c baryons negative parity states?

We calculate the mass and residue of the newly observed $\Omega_c(3000)$ and $\Omega_c(3066)$ states with quantum numbers $J^P = \frac{1}{2}^{-}$ and $\frac{3}{2}^{-}$ 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 BcB_c states in QCD

The mass and leptonic decay constants of recently observed two new excited $B_c$ 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 $m_{B_c^+}(2S) = 6.88 \pm 0.03~\rm{GeV}$ and $m_{B_c^{*+}}(2S) = 6.94 \pm 0.03~\rm{GeV}$ are in good agreement with the experimental data. Our predictions for the decay constants of these states are: $f_{B_c^+}(2S) = 0.42 \pm 0.02~\rm{GeV}$ and $f_{B_c^{*+}}(2S) = 0.46 \pm 0.01~\rm{GeV}$, 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 JPC=2−−J^{PC}=2^{--} Tensor Mesons in QCD

We present a study for two-quark light-cone distribution amplitudes for the $1^3D_2$ light tensor meson states with quantum number $J^{PC}=2^{--}$. 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 $f_T$ and $f_T^\perp$, and first Gegenbauer moment $a_1^\perp$, by using the QCD sum rule method. These parameters play a central role in the investigation of $B$ meson decaying into the $2^{--}$ tensor mesons.Comment: 18 pages, 3 Figure

Light-Cone Distribution Amplitudes of Light JPC=2−−J^{PC}=2^{--} Tensor Mesons in QCD

We present a study for two-quark light-cone distribution amplitudes for the $1^3D_2$ light tensor meson states with quantum number $J^{PC}=2^{--}$. 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 $f_T$ and $f_T^\perp$, and first Gegenbauer moment $a_1^\perp$, by using the QCD sum rule method. These parameters play a central role in the investigation of $B$ meson decaying into the $2^{--}$ 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 $A^\prime$, named as Dark Photon, associated with a group $U(1)_{\rm B-L}$ is studied in neutrino electron scattering experiments. The exclusion plot on the coupling constant $g_{\rm B-L}$ and the dark photon mass $M_{A^\prime}$ 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 Ωc0→Ω−l+νl\Omega_c^0 \rightarrow \Omega^- l^+ \nu_l and Ωc0→Ωc−π+(ρ+)\Omega_c^0 \rightarrow \Omega_c^- \pi^+ (\rho^+) decays in light cone sum rules

The semileptonic $\Omega_c^0 \rightarrow \Omega^- l \nu$ and non-leptonic $\Omega_c^0 \to \Omega^- \pi^+$, $\Omega_c^0 \to \Omega^- \rho^+$ decays of charmed $\Omega_c$ baryon are studied within the light cone sum rules. The form factors responsible for $\Omega_c \to \Omega$ transitions are calculated using the distribution amplitudes of $\Omega_c$ baryon. With the obtained form factors, the branching ratios of $\Omega_c^0 \to \Omega^- l^+ \nu_l$, $\Omega_c^0 \rightarrow \Omega^- \pi^+$, and $\Omega_c^0 \rightarrow \Omega^- \rho^+$ decays are estimated. The results are compared with Belle data as well as the findings of the other approaches