Search for the process $\mathbf{e^+e^- \toη}$

Abstract

A search for the rare decay $η\rightarrow e^+e^-$ is performed using the inverse process $e^+e^- \rightarrow η$ in the decay mode $η\toπ^0π^0π^0 $. We analyze data with an integrated luminosity of 654 nb$^{-1} $ accumulated at the VEPP-2000 $e^+e^-$ collider with the SND detector at the center-of-mass energy $E=m_ηc ^2\approx 548 $ MeV, and set the upper limit $ {\cal B} (η\rightarrow e^+ e^-) < 7 \times 10^{-7} $ at the 90\% confidence level.

9 pages, 4 figures