Determination of the Σ\Sigma--Λ\Lambda mixing angle from QCD sum rules

The $\Sigma$--$\Lambda$ mixing angle is calculated in framework of the QCD sum rules. We find that our prediction for the mixing angle is $(1.00\pm 0.15)^0$ which is in good agreement with the quark model prediction, and approximately two times larger than the recent lattice QCD calculations.Comment: 5 pages, no figures, LaTeX formatte

Study of the Λb→N∗ℓ+ℓ−\Lambda_{b} \to N^\ast \ell^+ \ell^- decay in light cone sum rules

The form factors of the $\Lambda_{b} \to N^\ast \ell^+ \ell^-$ decay are calculated in the framework of the light cone QCD sum rules. In the calculations the contribution of the negative parity $\Lambda_b^\ast$ baryon is eliminated by constructing the sum rules for different Lorentz structures. Furthermore the branching ratio of the semileptonic $\Lambda_b \to N^\ast \ell^+ \ell^-$ decay is calculated. The numerical study for the branching ratio of the $\Lambda_{b} \to N^\ast \ell^+ \ell^-$ decay indicates that it is quite large and could be measurable at future planned experiments to be conducted at LHCb.Comment: 21 pages, 2 figures, LaTeX formatte

Magnetic dipole moments of the heavy tensor mesons in QCD

The magnetic dipole moments of the ${\cal D}_2$, and ${\cal D}_{S_2}$, ${\cal B}_2$, and ${\cal B}_{S_2}$ heavy tensor mesons are estimated in framework of the light cone QCD sum rules. It is observed that the magnetic dipole moments for the charged mesons are larger than that of its neutral counterpart. It is found that the $SU(3)$ flavor symmetry violation is about 10\% in both $b$ and $c$ sectors.Comment: 16 pages, 6 figures, LaTeX formatte

Radiative decays of the p-wave charmed heavy baryons

The radiative decays of the p-wave charmed heavy baryons to the ground state baryon states are studied in the framework of the light cone QCD sum rules method. Firstly, the transition form factors that describe these transitions are estimated, and then using these form factors the corresponding decay widths are calculated. A comparison of our results on the decay widths with those predicted by the other approaches existing in literature is performed

Analysis of the radiative decays ΣQ→ΛQγ\Sigma_Q \to \Lambda_Q \gamma and ΞQ′→ΞQγ\Xi^\prime_Q \to \Xi_Q \gamma in light cone sum rules

The light cone sum rules method is used in studying the radiative decays $\Sigma_Q \to \Lambda_Q \gamma$ and $\Xi^\prime_Q \to \Xi_Q \gamma$. Firstly, the sum rules for the form factor $F_2(Q^2=0)$ responsible for these transitions is constructed. Using this result the decay widths of the above--mentioned decays are calculated and analyzed. A comparison of our predictions on the decay widths of considered transitions with the predictions of the other approaches is presented.Comment: 13 pages, no figures, LaTeX formatte

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