Production of new charmonium-like states in e+e -→J/Ψ D(-*)D(-*) at √s ≈ 10.6GeV
We present a study of the X(3940) state in the process e+e - → J/ Ψ D*)D. The X(3940) mass and width are measured to be (3942 +7-6±6)MeV/c2 and F = (37 +26 -15 ±8)MeV. In the process e+e- → J/ Ψ D*) +D*)- we have observed another charmonium-like state, which we denote as X(4160), in the spectrum of invariant masses of D*) +D*)- combinations. The X(4160) parameters are M =(4156 +25-20±15)MeV/c2 and F = (139 +111- 61±21)MeV. The analysis is based on a data sample with an integrated luminosity of 693 fb-1 recorded near the γ(4S) resonance with the Belle detector at the KEKB e +e- asymmetric-energy collider.