Heavy baryon--light vector meson couplings in QCD

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

Lepton polarization correlations in B→K∗τ−τ+B \to K^* \tau^- \tau^+

In this work we will study the polarizations of both leptons ($\tau$) in the decay channel $B\to K^* \tau^- \tau^+$. In the case of the dileptonic inclusive decay $B\to K^* \ell^- \ell^+$, where apart from the polarization asymmetries of single lepton $\ell$, one can also observe the polarization asymmetries of both leptons simultaneously. If this sort of measurement is possible then we can have, apart from decay rate, FB asymmetry and the six single lepton polarization asymmetries (three each for $\ell^-$ and $\ell^+$), nine more double polarization asymmetries. This will give us a very useful tool in more strict testing of SM and the physics beyond. We discuss the double polarization asymmetries of $\tau$ leptons in the decay mode $B\to K^* \tau^- \tau^+$ within the SM and the Minimal Supersymmetric extensions of it.Comment: 21 pages, 21 figures; version to match paper to appear in PR

Analysis of \Lambda_b \rar \Lambda \ell^+ \ell^- transition in SM4 using form factors from Full QCD

Using the responsible form factors calculated via full QCD, we analyze the $\Lambda_{b}\rightarrow \Lambda \ell^{+}\ell^{-}$ transition in the standard model containing fourth generation quarks (SM4). We discuss effects of the presence of $t'$ fourth family quark on related observables like branching ratio, forward-backward asymmetry, baryon polarization as well as double lepton polarization asymmetries. We also compare our results with those obtained in the SM as well as with predictions of the SM4 but using form factors calculated within heavy quark effective theory. The obtained results on branching ratio indicate that the $\Lambda_{b}\rightarrow \Lambda \ell^{+}\ell^{-}$ transition is more probable in full QCD comparing to the heavy quark effective theory. It is also shown that the results on all considered observables in SM4 deviate considerably from the SM predictions when $m_{t'}\geq 400 GeV$.Comment: 22 Pages and 21 Figure

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

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

B_s ---> \gamma \gamma decay in the model III and 3HDM(O_2) with CP violating effects

We analyse the CP asymmetry for B_{s} -->\gamma\gamma in the two Higgs doublet model with tree level flavor changing currents (model III) and three Higgs doublet model with O_2 symmetry in the Higgs sector, including O_{7} type long distance effects. Further, we study the dependencies of the branching ratio Br(B_{s} --> \gamma\gamma)$ and the ratio of CP-even and CP-odd amplitude squares, R=|A^{+}|^2/|A^{-}|^2, on the CP parameter sin \theta. We found that, there is a weak CP asymmetry, at the order of 10^{-4}. Besides, the branching ratio Br(B_{s} --> \gamma\gamma), and also R ratio, is not sensitive to the CP parameter for |\frac{\bar{\xi}^{U}_{N,tt}}{\bar{\xi}^{D}_{N,bb}}|<1.Comment: 17 pages, 11 figure

Heavy χQ2\chi_{Q_2} tensor mesons in QCD

The masses and decay constants of the ground state heavy $\chi_{Q2}(Q=b,c)$ 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

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

Mixing angle of doubly heavy baryons in QCD

We calculate the mixing angles between the spin--1/2, $\Xi_{bc}$--$\Xi^\prime_{bc}$ and $\Omega_{bc}$--$\Omega^\prime_{bc}$ states of doubly heavy baryons within the QCD sum rules method. It is found that the mixing angles are large and have the values $\varphi_{\Xi_{bc}} = 16^0 \pm 5^0$ and $\varphi_{\Omega_{bc}} = 18^0 \pm 6^0$, respectively. The mixing angles are slightly smaller compared to the predictions of the non--relativistic quark model, $\varphi_{\Xi_{bc}} = 25.5^0$ and $\varphi_{\Omega_{bc}} = 25.9^0$.Comment: 6 Page

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

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

Strong transitions of decuplet to octet baryons and pseudoscalar mesons

The strong coupling constants of light pseudoscalar $\pi$, $K$ and $\eta$ mesons with decuplet--octet baryons are studied within light cone QCD sum rules, where $SU(3)_f$ 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 $SU(3)_f$ symmetry breaking effects are switched into the game.Comment: 21 Pages, 2 Figures and 3 Table