Cross sections for the process e+e−→KS0KS0J/ψ
at center-of-mass energies from 4.128 to 4.950 GeV are measured using data
samples with a total integrated luminosity of 21.2 fb−1 collected by the
BESIII detector operating at the BEPCII storage ring. The Y(4230) state is
observed in the energy dependence of the e+e−→KS0KS0J/ψ cross section for the first time with a statistical significance of
26.0σ. In addition, an enhancement around 4.710 GeV, called the
Y(4710), is seen with a statistical significance of 4.2σ. There is no
clear structure around 4.484 GeV. Using a fit with a coherent sum of three
Breit-Wigner functions, we determine the mass and width of the Y(4230) state
to be 4226.9±6.6±21.9 MeV/c2 and 71.7±16.2±31.4 MeV,
respectively, and the mass and width of the Y(4710) state to be 4704.0±52.3±69.5 MeV/c2 and 183.2±114.0±90.8 MeV, respectively,
where the first uncertainties are statistical and the second are systematic. In
addition, the average Born cross section ratio of e+e−→KS0KS0J/ψ to e+e−→K+K−J/ψ is measured to be
0.388−0.028+0.035±0.016, or 0.426−0.031+0.038±0.018 if
three-body phase space is considered.Comment: Update draft based the comments from PRD refere