Total cross section for electron-positron annihilation into hadron final states in the upsilon energy region

Abstract

We report measurements made with the CLEO detector at the Cornell Electron Storage Ring (CESR) of the total cross section for ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons}$ at the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$, and in the nearby nonresonant continuum. We find $R=3.77\ifmmode\pm\else\textpm\fi{}0.06 (\mathrm{statistical}) \ifmmode\pm\else\textpm\fi{} 0.24 (\mathrm{systematic})$ for the ratio of the nonresonant hadronic cross section to the cross section for muon-pair production at a center-of-mass total energy $W=10.4$ GeV. For the leptonic decay widths ${\ensuremath{\Gamma}}_{\mathrm{ee}}$ of the $\ensuremath{\Upsilon}(1S)$, $\ensuremath{\Upsilon}(2S)$, and $\ensuremath{\Upsilon}(3S)$ we obtain 1.30\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.08, 0.52\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.04, and 0.42\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.03 keV, respectively.