Measurement of ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{e}^{+}{e}^{-}$ and ${\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}{\mu }^{+}{\mu }^{-}$

Abstract

Based on a sample of 225.3 million J/ψevents accumulated with the BESIII detector at the BEPCII, the decays of η' to pi+pi-l+l- are studied via J/ψto γη'. A clear η' signal is observed in the pi+pi-e+e- mass spectrum, and the branching fraction is measured to be \BR(η' to pi+pi-e+e-) = (2.11\pm0.12 (stat.)\pm0.15 (syst.))\times10^{-3}, which is in good agreement with theoretical predictions and the previous measurement, but is determined with much higher precision. No η' signal is found in the pi+ pi- mu+ mu- mass spectrum, and the upper limit is determined to be \BR(η' to pi+ pi- mu+ mu-)<2.9\times10^{-5} at the 90% confidence level.

7 pages, 7 figures

References in corpus (2)

• Study of ${\chi }_{cJ}$ radiative decays into a vector meson
• eta, eta-prime --> pi+ pi- l+ l- in a chiral unitary approach

Cited by in corpus (18)

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• Search for the weak decays $J/\psi \to D_s^{(\ast )}e{\nu }_e$
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