Related papers: \eta\ transitions between charmonia with meson loo…

We report the first observation of $B^0 \to J/\psi \eta$ decay. These results are obtained from a data sample that contains 449 million $B\bar{B}$ pairs accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB…

This study focuses on the decay of the $B_c$ meson to S-wave charmonia. Starting with lattice inputs on $B_c\to J/\psi$ form factors, we have obtained the $B_c\to\eta_c$ form factors using heavy quark spin symmetry (HQSS) relations between…

Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and…

We present the first search for the rare decay of $\eta^\prime$ into $K^{\pm}\pi^{\mp}$ in $J/\psi\to\phi\eta^{\prime}$, using a sample of $1.3\times10^{9}$ $J/\psi$ events collected with the BESIII detector. No significant signal is…

We, using an effective Lagrangian approach, investigated the dipionic transition of the $Y(4500)$ newly well established in the process $e^+e^-\to K^+K^- J/\psi$. In this study, the $Y(4500)$ was considered as a mixture of the $\psi(5S)$…

We analyze the decay of $\eta\rightarrow \ell^+\ell^-(\ell=e, \mu)$ via $J/\psi\rightarrow\gamma\eta'$ and $\eta'\rightarrow\pi^+\pi^-\eta$, based on (10087 $\pm$ 44) $\times$ 10$^{6}$ $J/\psi$ events collected with the BESIII detector at…

Based on a sample of \etapr mesons produced in the radiative decay $J/\psi\to\gamma\eta^{\prime}$ in $1.31\times 10^9$ $J/\psi$ events collected with the BESIII detector, the decay $\eta^{\prime}\to\omega e^{+} e^{-}$ is observed for the…

The effects of intermediate charmed mesons on charmonium transitions with the emission of one pion or eta are studied systematically. Based on a non-relativistic effective field theory we show that charmed meson loops are enhanced compared…

Using a sample of $4.48\times10^{8}$ $\psi(3686)$ events collected with the BESIII detector at the BEPCII collider, we study the two-photon decays of the pseudoscalar mesons $\pi^0$, $\eta$, $\eta^\prime$, $\eta(1405)$, $\eta(1475)$,…

With the new measurements of $J/\psi$ and $\psi^\prime\to \gamma\eta_c \ (\gamma\eta_c^\prime)$ from CLEO and BES-III Collaboration, we re-investigate the intermediate meson loop (IML) contributions to these radiative decays in association…

By analyzing $(448.1\pm2.9)\times10^6$ $\psi(3686)$ events collected with the BESIII detector operating at the BEPCII collider, the decays of $\chi_{cJ} \to \Lambda\bar \Lambda \eta$ ($J=0$, 1 and 2) are observed for the first time with…

First evidence of the $B^0\to J/\psi\omega$ decay is found and the $B_{s}^0\to J/\psi\eta$ and $B_{s}^0\to J/\psi\eta^{\prime}$ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 $\mathrm{fb}^{-1}$ collected…

We report first observations of $B_s^0\to J/\psi\eta$ and $B_s^0\to J/\psi\eta'$. The results are obtained from 121.4 fb^{-1} of data collected at the $\Upsilon(5S)$ resonance with the Belle detector at the KEKB $e^+e^-$ collider. We obtain…

The decays $J/\psi\to\eta\Sigma^{+}\bar{\Sigma}{}^-$ and $\psi(3686)\to\eta\Sigma^{+}\bar{\Sigma}{}^-$ are observed for the first time, using $(10087 \pm 44)\times 10^{6}$ $J/\psi$ and $(448.1 \pm 2.9)\times 10^{6}$ $\psi(3686)$ events…

Using a sample of $1.06\times10^8$ $\psi^\prime$ mesons collected with the BESIII detector at the BEPCII $e^+e^-$ collider and $\chi_{cJ}$ mesons produced via radiative transitions from the $\psi^\prime$, we report the first observation for…

The $\eta$-$\eta^\prime$ mixing angle is deduced from an updated phenomenological analysis of $J/\psi$ decays into a vector and a pseudoscalar meson. Corrections due to non-ideal $\omega$-$\phi$ mixing are confirmed to be crucial to find…

Using $(2712\pm 14)$ $\times$ 10$^{6}$ $\psi(2S)$ events collected with the BESIII detector at the BEPCII collider, we search for the decays $\eta_{c}(2S)\to\omega\omega$ and $\eta_{c}(2S)\to\omega\phi$ via the process…

We describe new measurements of the inclusive and exclusive branching fractions for Psi(2S) transitions to J/Psi using e+e- collision data collected with the CLEO detector operating at CESR. All branching fractions and ratios of branching…

Branching fraction ratios between the decays $B^{0}_{(s)} \rightarrow J/\psi \eta^{(\prime)}$ are measured using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of $7$, $8$ and $13~\textrm{TeV}$,…

Measurements of branching fractions for nine different final states, based on a data sample of approximately 4 million psi(2S) events collected with the BESI detector at the BEPC, are reported. Using the same event sample, radiative decays…