Related papers: Lepton Asymmetries in Heavy Baryon Decays of $\Lam…

Semi-leptonic and leptonic decays of B-mesons are important probes for testing SM and theories beyond it because of their relative cleanliness and far less theoretical uncertainties. In semi-leptonic decays based on quark level transition…

The exclusive (B -> K_2 l^+ l^-) decay is studied using the most general, model independent four-fermion interaction. The sensitivity of the ratio of the decay widths when K_2 meson is longitudinally and transversally polarized, the…

We study the forward-backward and the CP-violating asymmetries (both time-independent and time-dependent) in rare semileptonic $B_d\to\rho^0 l^+l^-$, $B_s\to\phi l^+l^-$, and radiative leptonic $B_{d,s}\to \gamma l^+l^-$ decays and…

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…

In the presence of an electric dipole coupling of t-tbar to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- --> t tbar results in modified polarization of the top and anti-top. This polarization…

The angular asymmetry in decays of polarized muons and tau leptons is discussed. Both the standard $V-A$ Fermi model and the general parameterization via Michel parameters are considered. Numerical importance of contributions suppressed by…

We calculate the amplitudes involved in the heavy baryon nonleptonic decay $\Lambda_b \rar \Lambda J/\psi$ using perturbative QCD factorization theorem, which are expressed as convolutions of hard $b$ quark decay amplitudes with the…

We analyze the weak decay of doubly-heavy baryon decays into anti-triplets $\Lambda_Q$ with light-cone sum rules. To calculate the decay form factors, both bottom and charmed anti-triplets $\Lambda_b$ and $\Lambda_c$ are described by the…

In this work we study the implication of the fourth generation standard model (SM4) to the single and double lepton polarization asymmetries in the $B\rightarrow K^{\ast}\ell^{+}\ell^{-}$, $(l=\mu,\tau)$ decay. To see the variation in the…

Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons…

In the standard model, we study CP violating rate asymmetries in the decay b->d l^+ l^- when one of the leptons is polarised. We find an asymmetry of (5 -- 15)% in the polarised decay spectrum which is comparable to known results for the…

We study the decay B --> K l^+ l^- for l = e,mu,tau with a softly recoiling kaon, that is, for high dilepton invariant masses sqrt{q^2} of the order of the b-quark mass. This kinematic region can be treated within an operator product…

We analyze rare charm baryon decays within the standard model and beyond. We identify all null test observables in unpolarized $\Lambda_c \to p \ell^+ \ell^-$, $\ell=e, \mu$ decays, and study the new physics sensitivities. We find that the…

Using the general, model independent form of the effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for (l^-) and (l^+) and combinations of them for the exclusive (B -> K l^+…

We investigate the Lambda_b polarization problem in the inclusive semileptonic decays of a polarized Lambda_b baryon, using the modified perturbative QCD formalism which includes Sudakov suppression. According to HQEFT, we show that, at the…

The forward-backward asymmetries of the processes e+e- -> Z -> b bbar and e+e- -> Z -> c cbar were measured from a sample of hadronic Z decays collected by the DELPHI experiment between 1993 and 1995. Enriched samples of b bbar and c cbar…

We calculate the invariant and helicity amplitudes for the nonleptonic decay Lambda_b -> Lambda + J/psi, psi(2S) in the covariant confined quark model. We discuss joint angular decay distributions in the cascade decay Lambda_b -> Lambda(->…

The longitudinal polarization, the transverse polarization, and the forward-backward asymmetry of Lambda baryons have been measured using a sample of 4.34 million hadronic Z^0 decays collected with the OPAL detector at LEP between 1990 and…

We reconsider the calculation of ${\cal O}(\Lambda^2_{QCD}/m^2_b)$ nonperturbative corrections to $\bar B\to X_sl^+l^-$ decay. Our analysis confirms the results of Ali et al. for the dilepton invariant mass spectrum, which were in…

A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay is presented. Systematically studied are the experimentally measured quantities, such as, branching ratio, forward-backward asymmetry, longitudinal polarization of…