4,424 research outputs found

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

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    The Σ\Sigma--Λ\Lambda mixing angle is calculated in framework of the QCD sum rules. We find that our prediction for the mixing angle is (1.00±0.15)0(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

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    The form factors of the Λb→N∗ℓ+ℓ−\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 Λb∗\Lambda_b^\ast baryon is eliminated by constructing the sum rules for different Lorentz structures. Furthermore the branching ratio of the semileptonic Λb→N∗ℓ+ℓ−\Lambda_b \to N^\ast \ell^+ \ell^- decay is calculated. The numerical study for the branching ratio of the Λb→N∗ℓ+ℓ−\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

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    The magnetic dipole moments of the D2{\cal D}_2, and DS2{\cal D}_{S_2}, B2{\cal B}_2, and BS2{\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)SU(3) flavor symmetry violation is about 10\% in both bb and cc sectors.Comment: 16 pages, 6 figures, LaTeX formatte

    Radiative decays of the p-wave charmed heavy baryons

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    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

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    The light cone sum rules method is used in studying the radiative decays ΣQ→ΛQγ\Sigma_Q \to \Lambda_Q \gamma and ΞQ′→ΞQγ\Xi^\prime_Q \to \Xi_Q \gamma. Firstly, the sum rules for the form factor F2(Q2=0)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

    Diagonal and transition magnetic moments of negative parity heavy baryons in QCD sum rules

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    Diagonal and transition magnetic moments of the negative parity, spin-1/2 heavy baryons are studied in framework of the light cone QCD sum rules. By constructing the sum rules for different Lorentz structures, the unwanted contributions coming from negative (positive) to positive (negative) parity transitions are removed. It is obtained that the magnetic moments of all baryons, except Λb0\Lambda_b^0, Σc+\Sigma_c^+ and Ξc′+\Xi_c^{\prime +}, are quite large. It is also found that the transition magnetic moments between neutral negative parity heavy ΞQ′0\Xi_Q^{\prime 0} and ΞQ0\Xi_Q^0 baryons are very small. Magnetic moments of the ΣQ→ΛQ\Sigma_Q \to \Lambda_Q and ΞQ′±→ΞQ± \Xi_Q^{\prime \pm} \to \Xi_Q^\pm transitions are quite large and can be measured in further experiments.Comment: 31 pages, 4 figures, LaTeX formatted. arXiv admin note: substantial text overlap with arXiv:1504.00172, arXiv:1504.0818
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