Study ofe+e−→ωχcJat Center of Mass Energies from 4.21 to 4.42 GeV

M. Ablikim, M. N. Achasov, X. C. Ai, O. Albayrak, M. Albrecht, D. J. Ambrose, A. Amoroso, F. F. An, Q. An, J. Z. Bai, R. Baldini Ferroli, Y. Ban (+397 others)
2015 Physical Review Letters  
Based on data samples collected with the BESIII detector at the BEPCII collider at 9 center-of-mass energies from 4.21 to 4.42 GeV, we search for the production of e^+e^-→ωχ_cJ (J=0, 1, 2). The process e^+e^-→ωχ_c0 is observed for the first time, and the Born cross sections at √(s)=4.23 and 4.26 GeV are measured to be (55.4± 6.0± 5.9) and (23.7± 5.3± 3.5) pb, respectively, where the first uncertainties are statistical and the second are systematic. The ωχ_c0 signals at the other 7 energies and
more » ... ^+e^-→ωχ_c1 and ωχ_c2 signals are not significant, and the upper limits on the cross sections are determined. By examining the ωχ_c0 cross section as a function of center-of-mass energy, we find that it is inconsistent with the line shape of the Y(4260) observed in e^+ e^-→π^+π^-J/ψ. Assuming the ωχ_c0 signals come from a single resonance, we extract mass and width of the resonance to be (4230±8±6) MeV/c^2 and (38±12±2) MeV, respectively, and the statistical significance is more than 9σ.
doi:10.1103/physrevlett.114.092003 pmid:25793804 fatcat:vi7vgd2bhbcu5dzz4hogdy24q4