Study of thee+e−→ηγprocess with Spherical Neutral Detector at the VEPP-2Me+e−collider

Abstract

In experiment with the SND detector at the VEPP-2M ${e}^{+}{e}^{\ensuremath{-}}$ collider the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\gamma}$ cross section was measured in the center-of-mass energy range $E=0.60--1.38\text{ }\text{ }\mathrm{GeV}$ with the integrated luminosity of $27.8\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. The measured cross section is well described by the vector meson dominance model with contributions from the $\ensuremath{\rho}(770)$, $\ensuremath{\omega}(783)$, $\ensuremath{\phi}(1020)$, ${\ensuremath{\rho}}^{\ensuremath{'}}(1465)$ resonances and agrees with results of previous measurements. The decay probabilities $\mathcal{B}(\ensuremath{\phi}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\gamma})$, $\mathcal{B}(\ensuremath{\omega}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\gamma})$ and $\mathcal{B}(\ensuremath{\rho}\ensuremath{\rightarrow}\ensuremath{\eta}\ensuremath{\gamma})$ were measured with the accuracies better than or comparable to the world averages.