Study of the rare decay J/ψ → e+e−ϕ**Supported by National Natural Science Foundation of China (11375128, 11425525), Sino-German CRC 110 Symmetries and the Emergence of Structure in QCD (11261130311)

Abstract

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 compared 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 other leading mechanism contributing. This result will be tested by the BESIII experiment with a large J/ψ data sample.