We study the decay process of J/ψ→e+e−ϕ where the relatively clean electromagnetic (EM) transitions appear at leading order at tree level while the hadronic contributions only emerge via hadronic loop transitions. We include the low-lying scalar f0(980) and pseudoscalar η/η′ as the dominant contributions in the evaluation of the hadronic loop contributions. It is found that the hadronic effects are negligible comparing with the EM contributions. The decay width of J/ψ→e+e−ϕ is determined to be about 2.12×10−6 keV if there is no any other leading mechanism contributing, and this result will be tested by the BESIII experiment with a large data sample of J/ψ.
@article{arxiv.1512.04149,
title = {Study of the rare decay $J/\psi\rightarrow e^+e^- \phi$},
author = {Xing-Dao Guo and Si-Run Xue and Hong-Wei Ke and Xue-Qian Li and Qiang Zhao},
journal= {arXiv preprint arXiv:1512.04149},
year = {2016}
}