Radiative dileptonic decays of B-meson in the general two Higgs doublet model

We investigate the exclusive $B\to \gamma \ell^+ \ell^-$ decay in the general two Higgs doublet model (model III) including the neutral Higgs boson effects with an emphasis on possible CP-violating effects. For this decay, we analyse the dependencies of the forward-backward asymmetry of the lepton pair, $A_{FB}$, CP-violating asymmetry, $A_{CP}$, and the CP-violating asymmetry in forward-backward asymmetry, $A_{CP}(A_{FB})$, on the model parameters and also on the neutral Higgs boson effects. We have found that $A_{FB}\sim 10^{-1}, 10^{-2}$, $A_{CP}\sim 10^{-2}, 10^{-1}$ and $A_{CP}(A_{FB}) \sim 10^{-2}, 10^{-1}$ depending on the relative magnitude of the Yukawa couplings $\bar{\xi}_{N,tt}^{U}$ and $\bar{\xi}_{N,bb}^{D}$ in the model III. We also observe that these physical quantities are sensitive to the model parameters and neutral Higgs boson effects are quite sizable for some values of the coupling $\bar{\xi}_{N,\tau \tau}^{D}$.Comment: 29 pages, 18 eps figures, requires appolb.cls (included

The analysis of Bd−>(η,η′)ℓ+ℓ−B_{d} -> (\eta, \eta^{\prime}) \ell^+ \ell^- decays in the standard model

We study the differential branching ratio, branching ratio and the CP-violating asymmetry for the exclusive $B_{d}->(\eta, \eta^{\prime}) \ell^+ \ell^-$ decays in the standard model. We deduce the $B_{d}->(\eta, \eta^{\prime})$ form factors from the form factors of $B -> \pi$ available in the literature, by using the $SU(3)_F$ symmetry. We observe that these decay modes, which are within the reach of forthcoming B-factories, are very promising to observe CP-violation.Comment: 12 pages, 8 figures, version to appear in Eur.Phys.J.

Isovector axial-vector form factors of octet baryons in QCD

We compute the diagonal isovector axial-vector as well as induced pseudoscalar form factors of nucleon, $\Sigma$ and $\Xi$ baryons by employing the light-cone QCD sum rules to leading order in QCD and including distribution amplitudes up to twist 6. Extrapolating our sum-rules results to low-momentum transfers, we make a comparison with experimental and lattice-QCD results where we can achieve a nice qualitative and quantitative agreement.Comment: 9 pages, 3 figure

The exclusive Bs−>ϕℓ+ℓ−B_s->\phi \ell^+ \ell^- decay in the two Higgs doublet models

We study the differential branching ratio, branching ratio and the forward-backward asymmetry for the exclusive $B_s->\phi \ell^+ \ell^-$ decay in the two Higgs doublet model. We analyze the dependencies of these quantities on the model parameters and show that these observables are highly sensitive to new physics and hence may provide powerful probe of the SM and beyond.Comment: 14 pages, 6 figures, version to appear in Eur.Phys.J.

Pseudoscalar-meson-octet-baryon coupling constants in two-flavor lattice QCD

We evaluate the πΝΝ, π∑∑, πΛ∑, KΛN and K∑N coupling constants and the corresponding monopole masses in lattice QCD with two flavors of dynamical quarks. The parameters representing the SU(3)-flavor symmetry are computed at the point where the three quark flavors are degenerate at the physical s-quark mass. In particular, we obtain α ≡ F/(F+D) = 0.395(6). The quark-mass dependences of the coupling constants are obtained by changing the u- and the d-quark masses. We find that the SU(3)-flavor parameters have weak quark-mass dependence and thus the SU(3)-flavor symmetry is brokenby only a few percent at each quark-mass point we consider.publisher versio