Related papers: The gluonic B and J/psi decays into the eta' meson
The eta(1760) may be significantly produced in J/Psi radiative decay. We deduce from experimental data that its branching ratio to two gluons is bounded, 0.4 +- 0.3 < BR(eta(1760) -> gg) < 0.9 +- 0.3, consistent with gluonic admixture.…
The observed inclusive decay of B-mesons into eta' + X is interpreted as the consequence of the gluonic decay of the b-quark into an s-quark. As a result of the QCD anomaly this decay proceeds partly as the decay b ---> s + eta', similar to…
Estimates of the branching ratios for B_{d,s}->J/psi eta and B_{d,s}->eta l+l- are obtained by SU(3) relation to B_d->J/psi K and B_d->K l+l-, respectively, as functions of the eta mixing parameter, theta_P. Based on these estimates, a…
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,…
The decay psi(2S) --> eta J/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching…
We propose a mechanism which can explain the large BR(B-> X_s eta')~ 10^(-3) observed by CLEO. In this mechanism, eta' is produced by the fusion of two gluons, one from QCD penguin b->sg and the other one emitted by the light quark inside…
Exclusive hadronic B-meson decays into two-body final states consisting of a light pseudoscalar or vector meson along with an eta or eta' meson are of great phenomenological interest. Their theoretical analysis involves decay mechanisms…
Instead of the glueball-$\eta'$ mixing ansatz, the latest measured ratios of the branching fractions of $B_{(s)}^0\to J/\psi \eta^{(\prime)}$ decays by LHCb can be understood by including the contribution from the light quark annihilation…
Motivated by the experimental study of $J/\psi\to\gamma ~+$ invisible decay by the CLEO Collaboration, we analyze the process $J/\psi\to \gamma \nu\bar{\nu}$, as the standard model background for this invisible decay, at the lowest order.…
Motivated by recent interest in soft $J/\Psi$ production in B decays, we investigate ${B}^0 \to J/\Psi D^{(\star)}$ and $\eta_c D^{(\star)}$ decays in perturbative QCD. We find that, within that framework, these decays are calculable since…
The large mass of the $\eta'$ meson indicates that a sizeable gluon component is present in the meson wave function. However, the $\chi_{c0}$ and $\chi_{c2}$ decays to $\eta'$ mesons, which proceed via a purely gluonic intermediate state…
The $\eta$-$\eta^\prime$ pseudoscalar mixing angle and the gluonium content of the $\eta^\prime$ meson are deduced from an updated phenomenological analysis of $J/\psi$ decays into a vector and a pseudoscalar meson. The values for the…
The $B_{c}$ ${\to}$ $J/{\psi}{\pi}$, ${\eta}_{c}{\pi}$ decays are studied in the scheme of the QCD factorization approach. The branching ratios are calculated with the asymptotic distribution amplitude of the pion. The charm quark mass…
Using a sample of $(1310.6\pm7.0)\times10^6$ $J/\psi$ events recorded with the BESIII detector at the symmetric electron positron collider BEPCII, we report the observation of the decay of the $(1^1 S_0)$ charmonium state $\eta_c$ into a…
Exclusive charmless B decays to $\eta'$ and $\eta$ are studied in the standard effective Hamiltonian approach. The effective coefficients that take into account nonfactorizable effects in external and internal W-emission amplitudes are…
The decays psi'->gamma pi^0, gamma eta and gamma eta' are studied using data collected with the BESIII detector at the BEPCII e^+e^- collider. Processes psi'->gamma pi^0 and psi'->gamma eta are observed for the first time with signal…
A study of $B^0$~and $B^0_s$ meson decays into $J/\psi\eta$~and $J/\psi\eta^{\prime}$ final states is performed using a data set of proton-proton collisions at centre-of-mass energies of 7 and 8TeV, collected by the LHCb experiment and…
We present an improved measurement of the eta' meson energy spectrum in Upsilon(1S) decays, using 1.2 fb^{-1}} of data taken at the Upsilon(1S) center-of-mass energy with the CLEO III detector. We compare our results with models of eta'…
The composition of the eta and eta' mesons has long been a source of discussion and is of current interest with new experimental results appearing. We investigate what can be learnt from a number of different processes: V to P gamma and P…
In the decays of $\eta_c\to\gamma\gamma$ and $J/\psi\to\gamma\eta_c$, there are discrepancies between the theoretical calculations and the PDG experimental values, referred to as the charmonium QCD puzzle. We observe the decay…