Abstract
The cross section for between threshold and is measured using of data on and off the resonance collected with the Belle detector at KEKB. Two resonant structures are observed in the invariant-mass distribution, one at with a width of , and another at with a width of , if the mass spectrum is parametrized with the coherent sum of two Breit-Wigner functions. These values do not match those of any of the known charmonium states.
- Received 25 July 2007
DOI:https://doi.org/10.1103/PhysRevLett.99.142002
©2007 American Physical Society