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 $\left( 2.42\pm0.05_{stat.}\pm0.08_{syst.} \right) \times 10^{-3}$. In addition, the CP-violating asymmetry in the angle between the decay planes of the $\pi^+\pi^-$-pair and the $e^+e^-$-pair is investigated. A measurable value would indicate physics beyond the standard model; the result is $\mathcal{A}_{CP} = \left(1.6\pm2.0_{stat.}\pm0.6_{syst.} \right)\%$, which is consistent with the standard model expectation of no CP-violation. The precision is comparable to the asymmetry measurement in the $K^0_L\to...
As published in PRD RC; some numbers slightly changedWe present measurements of the branching fracti...
We present measurements of the branching fractions for B0-meson decays to η′K0 and ωK0, and of the b...
Based on a sample of $(1310.6 \pm 7.0) \times 10^6~J/\psi$ events collected with the BESIII detector...
The rare decay η′ → π+π−e+e− is studied using a sample of 1.3×109 J/ψ events collected with the BES...
We have studied the eta→pi+pi-e+e-(gamma) decay using about 1.7 fb−1 collected by the KLOE experimen...
Using data samples collected with the BESIII detector at center-of-mass energies $\sqrt{s}$=4.23,4.2...
<p>Based on a sample of 225.3 million J/psi events accumulated with the BESIII detector at the BEPCI...
We have studied the eta -> pi(+)pi(-)e(+)e(-)(gamma) decay using about 1.7 fb(-1) collected by the K...
We study the CP-violating asymmetry, which arises, in \eta\to\pi^+\pi^- e^+ e^-, from the angular co...
Based on a sample of 225.3 million J/\psi events accumulated with the BESIII detector at the BEPCII,...
We have studied the η→π+π−e+e− (γ ) decay using about 1.7 fb−1 collected by the KLOE experiment at t...
The authors present measurements of the branching fractions for B{sup 0} meson decays to {eta}{prime...
Based on a sample of 225.3 million J/psi events accumulated with the BESIII detector at the BEPCII, ...
As published in PRD RC; some numbers slightly changedWe present measurements of the branching fracti...
We present measurements of the branching fractions for B0-meson decays to η′K0 and ωK0, and of the b...
Based on a sample of $(1310.6 \pm 7.0) \times 10^6~J/\psi$ events collected with the BESIII detector...
The rare decay η′ → π+π−e+e− is studied using a sample of 1.3×109 J/ψ events collected with the BES...
We have studied the eta→pi+pi-e+e-(gamma) decay using about 1.7 fb−1 collected by the KLOE experimen...
Using data samples collected with the BESIII detector at center-of-mass energies $\sqrt{s}$=4.23,4.2...
<p>Based on a sample of 225.3 million J/psi events accumulated with the BESIII detector at the BEPCI...
We have studied the eta -> pi(+)pi(-)e(+)e(-)(gamma) decay using about 1.7 fb(-1) collected by the K...
We study the CP-violating asymmetry, which arises, in \eta\to\pi^+\pi^- e^+ e^-, from the angular co...
Based on a sample of 225.3 million J/\psi events accumulated with the BESIII detector at the BEPCII,...
We have studied the η→π+π−e+e− (γ ) decay using about 1.7 fb−1 collected by the KLOE experiment at t...
The authors present measurements of the branching fractions for B{sup 0} meson decays to {eta}{prime...
Based on a sample of 225.3 million J/psi events accumulated with the BESIII detector at the BEPCII, ...
As published in PRD RC; some numbers slightly changedWe present measurements of the branching fracti...
We present measurements of the branching fractions for B0-meson decays to η′K0 and ωK0, and of the b...
Based on a sample of $(1310.6 \pm 7.0) \times 10^6~J/\psi$ events collected with the BESIII detector...