2005/07/31 by The Belle Collaboration, K. Abe · 1 citation
Physics and Astronomy · #hep-ex
paper · pdf · doi:10.1103/physrevlett.98.082001
published as Phys.Rev.Lett.98:082001,2007 · BELLE-CONF-0517
arxiv created 2005/11/08 · arxiv updated 2010/03/26
We report the first observation of a new charmonium state at a mass of (3.943 ± 0.006 ± 0.006) GeV/c2. This state, called X(3940), is observed in the process e+ e- → J/ψX(3940) in the spectrum of masses recoiling against a reconstructed J/ψ. We also observe the decay of the X(3940) into D^* D and measure the intrinsic width of this state to be less than 52 MeV/c2 at the 90% C.L. These results are obtained from a 350 fb-1 data sample collected with the Belle detector near the Υ(4S) resonance, at the KEKB asymmetric energy e+ e- collider.