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The Higgs-boson decay h -> gamma l+ l- for various lepton states l = (e, mu, tau) is analyzed. The differential decay width and forward-backward asymmetry are calculated as functions of the dilepton invariant mass in a model where the Higgs boson int eracts with leptons and quarks via a mixture of scalar and pseudoscalar couplings. These couplings are partly constrained from data on the decays to leptons, h -> l+ l-, and quarks h -> q bar{q} (where q = (c, b)), while the Higgs couplings to the top quark are chosen from the two-photon and two-gluon decay rates. Nonzero values of the forward-backward asymmetry will manifest effects of new physics in the Higgs sector. The decay width and asymmetry integrated over the dilepton invariant mass are also presented.
The branching ratio and other observables for the rare flavour-changing neutral current decay bar B_d^0 -> bar K*0 (-> K- pi+) e+ e- are studied below the bar{c} c threshold. The total amplitude for this decay includes the term coming from the standa rd model effective Hamiltonian and the term generated by the processes bar B_d^0 -> bar K*0 (-> K- pi+) V with intermediate low-lying vector resonances V = rho(770), omega(782), phi(1020) decaying into the e+ e- pair. The resonance contribution to the branching ratio, polarization fractions of the K* meson and coefficients in the angular distribution is calculated. The influence of the resonances on the integrated observables in the region of electron-positron invariant mass up to 1 GeV is studied in view of the planned measurements of the photon polarization at the LHCb.
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