The Search of the Process \({e^{+}e^{-}\to(\omega,\rho)\to\eta e^{+}e^{-}}\) at 680–820 MeV c.m. Energy Range with the CMD-3 Detector

Abstract

We report a search for the rare Dalitz decays \(\omega\to\eta e^{+}e^{-}\) and \(\rho\to\eta e^{+}e^{-}\) using data from the CMD-3 detector at the VEPP-2000 \(e^{+}e^{-}\) collider. These decays probe the electromagnetic structure of vector mesons and test the Vector Dominance Model (VDM) in low-energy QCD. A blind analysis technique, combined with kinematic constraints and multivariate methods, suppresses dominant backgrounds from \(\omega\to 3\pi\) and \(\omega\to\eta\gamma\) following with photon conversions. Preliminary results for the 2013 (12 pb\({}^{-1}\)) and 2018 (21 pb\({}^{-1}\)) datasets yield background estimates of \(N_{\text{bg}}=0.7\pm 0.4\) and \(1.9\pm 0.6\) events, respectively. This study demonstrates sensitivity to branching ratios at the \(10^{-6}\) level, establishing CMD-3 as a key instrument for precision tests of VDM predictions.