6,998 research outputs found

    Heavy baryon--light vector meson couplings in QCD

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    The strong coupling constants of heavy baryons with light vector mesons are calculated in the framework of the light cone QCD sum rules using the most general form of the interpolating currents for the heavy baryons. It is shown that the sextet--sextet, sextet--antitriplet and antitriplet--antitriplet transitions are described by one invariant function for each class of transitions. The values of the electric and magnetic coupling constants for these transitions are obtained.Comment: 16 Pages, 4 Figures and 7 Table

    B to tensor meson form factors in the perturbative QCD approach

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    We calculate the Bu,d,s→TB_{u,d,s}\to T form factors within the framework of the perturbative QCD approach, where TT denotes a light tensor meson with JP=2+J^P=2^+. Due to the similarities between the wave functions of a vector and a tensor meson, the factorization formulas of B→TB\to T form factors can be obtained from the B→VB\to V transition through a replacement rule. As a consequence, we find that these two sets of form factors have the same signs and correlated q2q^2-dependence behaviors. At q2=0q^2=0 point, the B→TB\to T form factors are smaller than the B→VB\to V ones, in accordance with the experimental data of radiative B decays. In addition, we use our results for the form factors to explore semilteptonic B→TlνˉlB\to Tl\bar \nu_l decays and the branching fractions can reach the order 10−410^{-4}.Comment: 13 pages, 3 figures, 6 tables, published versio

    Strong coupling constants of heavy spin--3/2 baryons with light pseudoscalar mesons

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    The strong coupling constants among members of the heavy spin--3/2 baryons containing single heavy quark with light pseudoscalar mesons are calculated in the framework of the light cone QCD sum rules. Using symmetry arguments, the structure independent relations among different correlation functions are obtained. It is shown that all possible transitions can be described in terms of one universal invariant function whose explicit expression is Lorenz structure dependent.Comment: 16 Pages, 1 figure and 1 Tabl

    Double-lepton polarization asymmetries in the (B -> K l^+ l^-) decay beyond the Standard Model

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    General expressions for the double-lepton polarizations in the (B -> K l^+ l^-) decay are obtained, using model independent effective Hamiltonian, including all possible interactions. Correlations between the averaged double-lepton polarization asymmetries and the branching ratio, as well as, the averaged single-lepton polarization asymmetry are studied. It is observed that, study of the double-lepton polarization asymmetries can serve as a good test for establishing new physics beyond the Standard Model.Comment: 21 pages, 18 figures, LaTeX formatte

    The Strong g_B(**)BPi Coupling Constant in full QCD

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    To leading order in alpha_s, the leading and non-leading 1/m_b corrections to the excited g_B^(**) meson coupling g_B^(**)BPi is calculated in the framework of QCD spectral moment sum rules in the full theory. Our prediction is in good agreement=20 with the light-cone QCD sum rule result.Comment: 7 pages,LaTeX formatte

    Magnetic moments of JP=32−J^P = {3\over 2}^- baryons in QCD

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    The magnetic moments of the low lying, negative parity, spin-3/2 baryons are calculated within the light cone QCD sum rules method. The contributions coming from the positive parity, spin-3/2 baryons, as well as from the positive and negative parity spin-1/2 baryons are eliminated by constructing combinations of various invariant amplitudes corresponding to the coefficients of the different Lorentz structures.Comment: 12 pages, 1 figure, LaTeX formatte

    Penguin induced (B -> eta) transition form factor in light cone QCD

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    We calculate the penguin form factor for the (B -> eta l^+ l^-) decay. This form factor is calculated in light cone QCD sum rules, including contributions from wave functions up to twist-4, as well as mass corrections of the light (eta) meson.Comment: 9 pages, 2 figures, LaTeX formatte
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