Measurement of $\varphi$(1020) meson leptonic width with CMD-2 detector at VEPP-2M Collider

Abstract

The $\varphi$(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance ($\varphi \to K^{+}{K}^{-},K_L^0{K}_S^0,{\pi }^{+}{\pi }^{-}{\pi }^0,\eta \gamma$) studied with the CMD-2 detector at the VEPP-2M $e^{+}{e}^{-}$ collider. The following value has been obtained: $\Gamma (\varphi \to e^{+}{e}^{-})=1.235\pm 0.006\pm 0.022$ keV. The $\varphi (1020)$ meson parameters in four main decay channels have been also recalculated: $B(\varphi \to K^{+}{K}^{-})=0.493\pm 0.003\pm 0.007$, $B(\varphi \to K_L{K}_S)=0.336\pm 0.002\pm 0.006$, $B(\varphi \to {\pi }^{+}{\pi }^{-}{\pi }^0)=0.155\pm 0.002\pm 0.005$, $B(\varphi \to \eta \gamma )=0.0138\pm 0.0002\pm 0.0002$.

14 pages, 3 figures