Confirmation of the Y(4260) Resonance Production in ISR

TL;DR

This paper confirms the production of the Y(4260) resonance in initial state radiation events using CLEO III data, providing precise measurements of its mass, width, and electronic decay width times branching ratio.

Contribution

It provides the first independent confirmation of the Y(4260) resonance production and decay, with detailed measurements of its properties.

Findings

Y(4260) production confirmed in ISR

Measured mass approximately 4284 MeV/c^2

Determined resonance width around 73 MeV

Abstract

Using 13.3 fb^-1 of e+e- collision data taken in the Upsilon(1S-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 pi+pi-J/psi are confirmed. A good quality fit to our data is obtained with a single resonance. We determine M(Y(4260))=(4284+17-16(stat)+-4(syst)) MeV/c^2, Gamma(Y(4260))=(73+39-25(stat)+-5(syst)) MeV/c^2, and Gamma_ee(Y(4260))xBr(Y(4260)->pi+pi-J/psi)=(8.9+3.9-3.1(stat)+-1.9(syst)) eV/c^2.