Confirmation of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Y</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>4260</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math>resonance production in initial state radiation

Using $13.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data taken in the $\ensuremath{\Upsilon}(1S\ensuremath{-}4S)$ region with the CLEO III detector at the CESR collider, a search has been made for the new resonance $Y(4260)$ recently reported by the BABAR Collaboration. The production of $Y(4260)$ in initial state radiation (ISR), and its decay into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$, are confirmed. A good quality fit to our data is obtained with a single resonance. We determine $M(Y(4260))=({4284}_{\ensuremath{-}16}^{+17}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}4(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, $\ensuremath{\Gamma}(Y(4260))=({73}_{\ensuremath{-}25}^{+39}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}5(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and ${\ensuremath{\Gamma}}_{ee}(Y(4260))\ifmmode\times\else\texttimes\fi{}\mathcal{B}(Y(4260)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=({8.9}_{\ensuremath{-}3.1}^{+3.9}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{syst}))\text{ }\text{ }\mathrm{eV}/{c}^{2}$.