Measurement of e+e- -> pi+pi- cross section with CMD-2 around rho(770) meson

Abstract

In experiments with the CMD-2 detector at the VEPP-2M electron-positron collider at Novosibirsk about 150000 $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ events were recorded in the center-of-mass energy range from 0.61 up to 0.96 GeV. The result of the pion form factor measurement with a 1.4% systematic error is presented. The following values of the $\rho$-meson and $\rho -\omega$ interference parameters were found: $M_{\rho }=(775.28\pm 0.61\pm 0.20)MeV,{\Gamma }_{\rho }=(147.70\pm 1.29\pm 0.40)MeV,\Gamma (\rho \to e^{+}{e}^{-})=(6.93\pm 0.11\pm 0.10)keV,Br(\omega \to {\pi }^{+}{\pi }^{-})=(1.32\pm 0.23)$.

52 pages