Related papers: A gluonic mechanism for B --> D eta'
The E2/M1 ratio (EMR) of the $\Delta$(1232) is extracted from the world data in pion photoproduction by means of an Effective Lagrangian Approach (ELA).This quantity has been derived within a crossing symmetric, gauge invariant, and chiral…
We analyse the CP asymmetry of the B --> phi K and B --> eta' K processes in general supersymmetric models. We consider both gluino and chargino exchanges in a model independent way by using the mass insertion approximation method. We adopt…
Elastic scattering of charm (c) and bottom (b) quarks via D- and B-meson resonance states in an expanding, strongly interacting quark-gluon plasma is investigated. Drag and diffusion coefficients are calculated from an effective model based…
We point out that the recent Belle measurements of the $B_{d/s} \to J/\Psi \eta^{(')}$ decays imply large pseudoscalar glueball contents in the $\eta^{(\prime)}$ meson. These decays are studied in the perturbative QCD (PQCD) approach,…
Traditional Stueckelberg Mechanism is shown equivalent to set up a gauged U(1) chiral Lagrangian and fix special gauge. With this mechanism, the original electro-weak chiral Lagrangian is inlarged by including an extra U(1) symmetry to…
Given a resonance of known mass, width, and J^{PC}, we can determine its gluonic branching fraction, b(R->gg), from data on its production in radiative vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to be…
The decays eta, eta-prime --> pi+ pi- l+ l- (with l = e, mu) are investigated within a chiral unitary approach which combines the chiral effective Lagrangian with a coupled-channels Bethe-Salpeter equation. Predictions for the decay widths…
The $\eta'$ which is an $SU(3)_F$ singlet state can contain a pure gluon component, gluonium. We examine this possibility by analysing all available experimental data. It is pointed out that the $\eta'$ gluonic component may be as large as…
Using the recently proposed $gg --> eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in $pA$ collisions. We show that measuring $\eta'$ production cross-section at moderate $x_{\eta'}$ yields direct…
We report the observation of B0bar --> D0 eta' and the first observation of B0bar --> D*0 eta', using 140 fb-1 of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric energy e+ e- collider. We find the…
It is interesting to determine the fraction of the gluonium component in $\eta$ and $\eta'$ which has been under serious discussion for many years. Measurements on different decay and/or production modes were employed in literatures, thus…
We present measurements of the B->eta K gamma branching fractions and upper limits for the B->eta' K gamma branching fractions. For B->eta K+ gamma we also measure the time-integrated charge asymmetry. The data sample, collected with the…
We study the $\eta$ and $\eta'$ distribution amplitudes (DAs) in the context of a nonlocal SU(3)_L x SU(3)_R chiral quark model. The corresponding Lagrangian allows to reproduce the phenomenological values of pseudoscalar meson masses and…
Using the latest data pertaining to \bar u-\bar d asymmetry and the spin polarization functions, detailed implications of the possible values of the coupling strength of the singlet Goldstone boson \eta' have been investigated in the…
An extensive and systematic study of the recent eta photoproduction data up to 1.2 GeV is presented within a chiral constituent quark model. A model embodying all known nucleonic resonances shows clear need for a yet undiscovered third S11…
A detailed investigation of the low-energy chiral expansion is presented within a model truncation of QCD. The model dependence of the chiral coefficients is tested for several forms of the quark-quark interaction by varying the form of the…
The charged current (anti)neutrino induced eta production from the nucleons is studied in a model based on the effective Lagrangians to evaluate the contribution from the nonresonant and resonant diagrams. The contribution from the…
Rare weak decays of $\eta^\prime\to K\pi$ have been investigated in the framework of the $U(3)$ chiral perturbation theory at the leading order. Our study shows that the branching ratio ${\cal B}(\eta^\prime\to K\pi)$ is of the order of…
Semileptonic and leptonic B decays are analyzed in the framework of the relativistic quark model. Special attention is payed to the decays involving $\tau$ lepton. It is found that the calculated particular decay branching fractions are…
The mass matrix for $\eta-\eta^\prime$ is derived in the flavor basis at ${\cal O}(p^4)$ of the chiral Lagrangian using the large $N$ approximation. Under certain assumptions, the mixing angle $\phi=41.4^\circ$ and the decay constants ratio…