Abstract
We study initial-state radiation events, , with data collected with the BABAR detector. We observe an accumulation of events near in the invariant-mass spectrum of . Fits to the mass spectrum indicate that a broad resonance with a mass of about is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to , depending on the fit hypothesis.
- Received 28 June 2005
DOI:https://doi.org/10.1103/PhysRevLett.95.142001
©2005 American Physical Society