A measurement of the electronic widths Γ_ee of the Υ{hooked}(1 S), Υ{hooked}(2 S), and Υ{hooked}(4 S) resonances, and of the total decay width Γ of the Υ{hooked}(4 S)

The partial decay width into electrons, Γ_ee, of the Υ{hooked}(1 S) and Υ{hooked}(2 S) resonances have been measured with the detector ARGUS at the e⁺e^- storage ring DORISII of DESY. Applying the formula of Kuraev and Fadin for the radiative corrections we find: Γ_ee(Υ{hooked}(1 S))= (1.32±0.04±0.03) keV and Γ_ee(Υ{hooked}(2 S))=(0.52±0.03±0.01) keV. The total decay width of the Υ{hooked}(4 S) resonance and its partial width into electrons have been determined as well. Fitting the data with a generalized Breit-Wigner function with an energy dependent decay width Γ(s) and a mass shift function m(s), we obtain the following resonance parameters: Γ(M²)=(10.0±2.8±2.7) MeV, Γ_ee=(0.28±0.05±0.01)keV and B_ee=(2.77±0.50±0.49)·10^-5. We argue that the disagrecment of this result with the world average originates from our more adequate parametrization of the observed Υ{hooked}(4 S) resonance cross section.