Semileptonic decays of pseudoscalar mesons to scalar "f_0" meson

The transition form factors of (D_s -> f_0 l nu), (D -> f_0 l nu) and (B_u -> f_0 l nu) decays are calculated in 3-point QCD sum rule method, assuming that "f_0" is a quark-antiquark state with a mixture of strange and light quarks. The branching ratios of these decays are calculated in terms of the mixing angle.Comment: 12 pages, 4 figures, LaTeX formatte

Octet baryon magnetic moments in light cone QCD sum rules

Octet baryon magnetic moments are calculated in framework of the light cone QCD sum rules. The analysis is carried for the general form of the interpolating currents for octet baryons. A comparison of our results on the magnetic moments of octet baryons with the predictions of other approaches and experimental data is presented.Comment: 20 pages, 10 figures, 1 Table, LaTeX formatte

Fourth generation effects in processes induced by "b -> s" transition

We study the effects of sequential fourth quark generation in rare "B -> K(K*) l^+ l^-" decays induced by "b -> s" transition and in "B_s^0 - bar{B}_s^0" mixing. Using the experimental values on branching ratios of the "B -> X_s gamma" and "B -> K(K*) l^+ l^-" decays, the allowed regions for \vel V_{tb} V_{ts}^\ast\ver and "|V_{t'b} V_{t's}*| are determined as a function of the (t') quark mass.Comment: 18 pages, 8 figures, LaTeX formatte

Double-lepton polarizations in (B -> l^+ l^- gamma) decay

Double-lepton polarization asymmetries in the (B -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian including all possible forms of the interaction. The dependencies of the asymmetries on new Wilson coefficients are investigated. The detectability the averaged double-lepton polarization asymmetries at LHC is also discussed.Comment: 20 pages, 7 PostScript figures, LaTeX formatte

New physics effects in (Lambda_b -> Lambda l^+ l^-) decay with lepton polarizations

We study lepton polarization asymmetries in the (Lambda_b -> Lambda l^+ l^-) decay using the most general model independent effective Hamiltonian. The dependence of the lepton polarizations and their combinations on the new Wilson coefficients are studied in detail. It is observed that there is a region for the new Wilson coefficients for which the branching ratio coincides with the standard model prediction, while lepton polarizations show considerable departure from standard model.Comment: 18 pages, 11 figures, LaTeX formatte

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

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