Study of e+e-→π+π-J/ψ and Observation of a Charged Charmoniumlike State at Belle
Abstract
The cross section for e+e-→π+π-J/ψ between 3.8 and 5.5 GeV is measured with a 967fb-1 data sample collected by the Belle detector at or near the Υ(nS) (n=1,2,…,5) resonances. The Y(4260) state is observed, and its resonance parameters are determined. In addition, an excess of π+π-J/ψ production around 4 GeV is observed. This feature can be described by a Breit-Wigner parametrization with properties that are consistent with the Y(4008) state that was previously reported by Belle. In a study of Y(4260)→π+π-J/ψ decays, a structure is observed in the M(π±J/ψ) mass spectrum with 5.2σ significance, with mass M=(3894.5±6.6±4.5)MeV/c2 and width Γ=(63±24±26)MeV/c2, where the errors are statistical and systematic, respectively. This structure can be interpreted as a new charged charmoniumlike state.
- Publication:
-
Physical Review Letters
- Pub Date:
- June 2013
- DOI:
- 10.1103/PhysRevLett.110.252002
- Bibcode:
- 2013PhRvL.110y2002L
- Keywords:
-
- 14.40.Rt;
- 13.25.Gv;
- 13.66.Bc;
- 14.40.Pq;
- Decays of J/psi Upsilon and other quarkonia;
- Hadron production in e<sup>-</sup>e<sup>+</sup> interactions