Related papers: Mixing effects of $\eta-\eta'$ in $\Lambda_b\right…
We present preliminary measurements of branching fractions and charge asymmetries for the B meson decays B -> eta(')K*, B -> eta(')rho, and B+ -> eta' pi+. The data were recorded with the BaBar detector at PEP-II and correspond to 89 x 10^6…
We report the first measurements of the branching fractions: $B(\psi(2S) -> \gamma \eta') = (1.54 \pm 0.31 \pm 0.23) x 10^{-4}$ and $B(\psi(2S) -> \gamma \eta) = (0.53 \pm 0.31 \pm 0.08) x 10^{-4}$. The $\psi(2S)$ to $\gamma \eta'$ result…
In perturbative QCD approach, based on the first order of isospin symmetry breaking, we study the direct $CP$ violation in the decay of $\bar{B}_s^0\to\rho(\omega )K^{*0}\to {\pi^+}{\pi^-}K^{*0}$. An interesting mechanism is applied to…
A large number of new experimental data on $B$ decay into two light pesudoscalar ($P$) mesons have been collected by the LHCb collaboration. Besides confirming information on $B_{u,d} \to PP$ decays obtained earlier by B-factories at KEK…
We propose a new eta-eta' mixing scheme where we start from the quark flavor basis and assume that the decay constants in that basis follow the pattern of particle state mixing. On exploiting the divergences of the axial vector currents -…
The observation of a sizable direct CP asymmetry in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, this asymmetry is below 1% in magnitude. In extensions of the Standard Model with new…
A phenomenological analysis on various decay processes is performed using an energy-dependent $\eta-\eta'$ mixing angle scheme. Special attention is given to the radiative couplings between lowest-lying vector and pseudoscalar mesons. The…
We extract $\eta$-$\eta^\prime$ mixing angle and the ratios of decay constants of light pseudoscalar mesons $\pi^0$, $\eta$ and $\eta^\prime$ using recently available BaBar measurements on $\eta$-photon and $\eta^\prime$-photon transition…
The branching ratio of the electromagnetic rare decays $\eta\to\pi^0\gamma\gamma$ and $\eta^\prime\to (\pi^0,\eta)\gamma\gamma$ are analysed in terms of scalar and vector meson exchange contributions using the frameworks of the Linear Sigma…
In this paper we study the semileptonic decays of $B_c^- \to (\eta_c,J/\psi)l^-\bar\nu_l$. We firstly evaluate the $B_c \to (\eta_c,J/\Psi)$ transition form factors $F_0(q^2)$, $F_+(q^2)$, $V(q^2)$ and $A_{0,1,2}(q^2)$ by employing the pQCD…
In this work we estimate the helicity suppressed decay rates of $\eta_b$ resonances into baryon pairs due to instanton-induced effects by rescaling the corresponding partial widths of the experimentally measured branching ratios for the…
In this proceedings we present a measurement of mixing, and searches for direct and indirect CP asymmetries in the charm sector using the full \babar data sample of $469 \invfb$. Searches for direct CP asymmetries have been performed in the…
We study the decays $\Lambda_{c}^{+}\to\Lambda\eta\pi^{+}$ and $\Sigma(1385)^{+}\eta$ based on $\Lambda_{c}^{+}\bar{\Lambda}_{c}^{-}$ pairs produced in $e^+e^-$ collisions at a center-of-mass energy of $\sqrt{s}=4.6~\mbox{GeV}$,…
We derive model-independent bounds on the form factors for the decay $B_c^+ \to \eta_c\, \ell^+\, \nu$ including full mass effects, i.e. $\ell = e,\, \mu, \text{ and } \tau$. The bounds are obtained by using the BGL parameterization for the…
Using 15.1 pb^{-1} of data collected by CMD-2 in the phi-meson energy range, the branching ratios of the following conversion decays have been measured: B(\phi\to\eta e^+e^-) = (1.14\pm0.10\pm0.06)\cdot10^{-4}, B(\eta\to e^+e^-\gamma) =…
Motivated by systematic observations of $ B_c $ decays at LHCb, we analyze $B_c^+ \to J/\psi (A, T)$ decays (where $A$ denotes axial-vector mesons $a_1(1260)^+$, $b_1(1235)^+$, and $T$ denotes tensor mesons $a_2(1320)^+$, $K_2^*(1430)^+$)…
In a sample of 19 million produced B mesons we have observed decays B -> eta K*, and improved our previous measurements of B -> eta' K. The branching fractions we measure for these decay modes are B(B+ -> eta K*+) = (27.3 +9.6 -8.2 (stat)…
Nonleptonic two body $B_c$ decays including radially excited $\psi(2S)$ or $\eta_c(2S)$ mesons in the final state are studied using the perturbative QCD approach based on $k_T$ factorization. The charmonium distribution amplitudes are…
We present a lattice QCD computation of $\eta$ and $\eta^\prime$ masses and mixing angles, for the first time controlling continuum and quark mass extrapolations. The results for the eta mass 551(8)(6) MeV (first error statistical, second…
Due to the heavy-quark symmetry of Non-Relativistic Quantum Chromodynamics (NRQCD), the cross-section for the production of $\eta_c$ can be predicted. This NRQCD prediction when confronted with data from the LHCb is seen to fail miserably.…