ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2007, vol. 98, p. -
Observation of a charmoniumlike state produced in association with a J/ψ in e+e- annihilation at s 10.6GeV
We report the first observation of a charmoniumlike state recoiling from the J/ψ in the inclusive process e+e-→J/ψ+anything at a mass of (3.943±0.006±0.006)GeV/c2. We also observe the decay of this state into D*D̄ and determine its intrinsic width to be less than 52MeV/c2 at the 90% C.L. These results are obtained from a 357fb-1 data sample collected with the Belle detector near the Υ(4S) resonance, at the KEKB asymmetric-energy e+e- collider. © 2007 The American Physical Society.