Masses, Widths, and Leptonic Widths of the Higher Upsilon Resonances

Abstract

The masses, total widths, and leptonic widths of three triplet $s$-wave $b\overline{b}$ states $\ensuremath{\Upsilon}(4S)$, $\ensuremath{\Upsilon}(5S)$, and $\ensuremath{\Upsilon}(6S)$ are determined from measurements of the ${e}^{+}{e}^{\ensuremath{-}}$ annihilation cross section into hadrons for $10.55<W<11.25$ GeV. The resonances are identified from potential model results and their properties are obtained with the help of a simplified coupled-channels calculation. We find $M(4S)=10.577$ GeV, $\ensuremath{\Gamma}(4S)=25$ MeV, ${\ensuremath{\Gamma}}_{\mathrm{ee}}(4S)=0.28$ keV; $M(5S)=10.845$ GeV, $\ensuremath{\Gamma}(5S)=110$ MeV, ${\ensuremath{\Gamma}}_{\mathrm{ee}}(5S)=0.37$ keV; $M(6S)=11.02$ GeV, $\ensuremath{\Gamma}(6S)=90$ MeV, ${\ensuremath{\Gamma}}_{\mathrm{ee}}(6S)=0.16$ keV.