10,460 research outputs found

    Heavy baryon--light vector meson couplings in QCD

    Get PDF
    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

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

    Get PDF
    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

    Exclusive B -> K^* l^+ l^- decay with polarized K^* and new physics effects

    Get PDF
    Using the most general, model independent effective Hamiltonian, the branching ratio of the (B -> K^* l^+ l^-) decay, when K^* meson is longitudinally or transversally polarized, is presented. The dependence of the branching ratio on the new Wilson coefficients, when K^* meson is polarized, is studied. It is observed that the branching ratio is very sensitive to the vector and tensor type interactions, which will be useful in search of new physics beyond the Standard Model.Comment: 13 pp, 6 figures (postscript formatted), LaTex formatte

    B to tensor meson form factors in the perturbative QCD approach

    Full text link
    We calculate the Bu,d,sTB_{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 BTB\to T form factors can be obtained from the BVB\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 BTB\to T form factors are smaller than the BVB\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 BTlνˉlB\to Tl\bar \nu_l decays and the branching fractions can reach the order 10410^{-4}.Comment: 13 pages, 3 figures, 6 tables, published versio

    Strong transitions of decuplet to octet baryons and pseudoscalar mesons

    Get PDF
    The strong coupling constants of light pseudoscalar π\pi, KK and η\eta mesons with decuplet--octet baryons are studied within light cone QCD sum rules, where SU(3)fSU(3)_f symmetry breaking effects are taken into account. It is obtained that all coupling constants under the consideration are described by only one universal function even if SU(3)fSU(3)_f symmetry breaking effects are switched into the game.Comment: 21 Pages, 2 Figures and 3 Table

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

    Full text link
    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

    General analysis of time evolution of decay spectrum in B^0 -> pi^+ pi^- l^+ l^-

    Full text link
    Using the general, model independent form of effective Hamiltonian, the decay spectrum of B^0 -> pi^+ pi^- l^+ l^- decay is studied. The sensitivity of experimentally measurable asymmetries to the new Wilson coefficients and time is studied. It is observed that different asymmetries are sensitive to the new Wilson coefficients and they can serve as an efficient tool for establishing new physics beyond SM.Comment: 15 pp, 4 figures (postscript formatted), LaTex formatte

    Heavy χQ2\chi_{Q_2} tensor mesons in QCD

    Get PDF
    The masses and decay constants of the ground state heavy χQ2(Q=b,c)\chi_{Q2}(Q=b,c) tensor mesons are calculated in the framework of the QCD sum rules approach. The obtained results on the masses are in good consistency with the experimental values. Our predictions on the decay constants can be verified in the future experiments.Comment: 7 Pages and one Tabl

    General analysis of lepton polarizations in rare B -> K^* l^+ l^- decay beyond the standard model

    Get PDF
    The general analysis of lepton polarization asymmetries in rare B -> K^* l^+ l^- decay is investigated. Using the most general, model independent effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for l^- and l^+ and combinations of them are presented. The dependence of lepton polarizations and their combinations on new Wilson coefficients are studied in detail. Our analysis shows that the lepton polarization asymmetries are very sensitive to the scalar and tensor type interactions, which will be very useful in looking for new physics beyond the standard model.Comment: 29 pp, 15 figure
    corecore