相关论文: Study of $\eta\rightarrow\pi^+\pi^-l^+l^-$

Using a sample of 10 billion $J/{\psi}$ events collected with the BESIII detector, the decays $\eta' \to \pi^{+}\pi^{-}\pi^{+}\pi^{-}$, $\eta' \to \pi^{+}\pi^{-}\pi^{0}\pi^{0}$ and $\eta' \to 4 \pi^{0}$ are studied via the process…

Based on a sample of 225.3 million J/\psi events accumulated with the BESIII detector at the BEPCII, the decays of \eta' to pi+pi-l+l- are studied via J/\psi to \gamma\eta'. A clear \eta' signal is observed in the pi+pi-e+e- mass spectrum,…

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…

With a sample of $(10087\pm44)\times10^{6}$ $J/\psi$ events accumulated with the BESIII detector, we analyze the decays $\eta'\rightarrow\pi^+\pi^-l^+l^-(l=e,$ $\mu)$ via the process $J/\psi\rightarrow\gamma\eta'$. The branching fractions…

The rare decay $\eta' \to \pi^+ \pi^- e^+ e^-$ is studied using a sample of $1.3 \times 10^9$ $J/\psi$ events collected with the BESIII detector at BEPCII in 2009 and 2012. The branching fraction is measured with improved precision to be…

Using $(1310.6 \pm 7.0) \times 10^{6}~J/\psi$ events acquired with the BESIII detector at the BEPCII storage rings, the decay $\eta^\prime\rightarrow\pi^+\pi^-\mu^+\mu^-$ is observed for the first time with a significance of 8$\sigma$ via…

Based on a sample of $ (10.087\pm 0.044)\times 10^{9} J/\psi$ events collected by the BESIII detector at the BEPCII collider, we perform the first search for the lepton number violating decay $\eta \to \pi^+\pi^+ e^-e^- + \text{c.c.}$ No…

Using a sample of $(10087 \pm 44) \times 10^{6}$ $J/\psi$ events collected with the BESIII detector, an improved measurement of the decay $\eta^{\prime}\rightarrow e^{+}e^{-}\omega$, with $\omega\rightarrow\pi^{+}\pi^{-}\pi^{0}$ and…

Based on a sample of $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events collected at BESIII, the transition form factor of the $\eta$ meson is extracted by analyzing $J/\psi\to\gamma\eta',~\eta'\to\pi^+\pi^-\eta,~\eta\to\gamma l^+l^-$…

Using an $e^+e^-$ annihilation data sample corresponding to an integrated luminosity of $2.93\,\rm fb^{-1}$ collected at the center-of-mass energy of 3.773\,GeV with the BESIII detector, we measure the absolute branching fractions of…

Based on a sample of $1.31 \times 10^9$ $J/\psi$ events collected with the BESIII detector, an amplitude analysis of the isospin-violating decays $\eta^\prime \rightarrow \pi^+\pi^-\pi^0$ and $\eta^\prime \rightarrow \pi^0\pi^0\pi^0$ is…

The lepton number violation decay $\omega \to \pi^+ \pi^+ e^-e^- +c.c.$ is searched for via $J/\psi \to \omega\eta$ using a data sample of $(1.0087 \pm 0.0044) \times 10^{10}$ $J/\psi$ events collected by the BESIII detector at the BEPCII…

Based on a sample of 1.31 billion $J/\psi$ events collected with the BESIII detector, we perform a search for the rare decay $\eta'\rightarrow 4\pi^{0}$ via $J/\psi\rightarrow\gamma\eta'$. No significant $\eta'$ signal is observed in the…

Using $(1.0087\pm0.0044)\times10^{10}$ $J/\psi$ events collected by the BESIII detector at the BEPCII collider, we search for the lepton number violation decay $\phi \to \pi^+ \pi^+ e^- e^-$ via $J/\psi\to \phi\eta$. No signal is found and…

Using a data sample of $4.481\times 10^8 \psi^\prime$ events collected with the BESIII detector, we report the first observation of the four-lepton-decays $J/\psi\to e^+e^-e^+e^-$ and $J/\psi\to e^+e^-\mu^+\mu^-$ utilizing the process…