Final analysis of KEDR data on J/ψ and ψ(2S) masses

Abstract We present the analysis of all KEDR data on the determination of J / ψ and ψ ( 2 S ) masses. The data comprise six scans of J / ψ and seven scans of ψ ( 2 S ) which were performed at the VEPP-4M e + e − collider in 2002–2008. The beam energy was determined using the resonance depolarization method. The detector and accelerator conditions during scans were very different that increases the reliability of the averaged results. The analysis accounts for partial correlations of systematic uncertainties on the masses. The following mass values were obtained: M J / ψ = 3096.900 ± 0.002 ± 0.006  MeV , M ψ ( 2 S ) = 3686.099 ± 0.004 ± 0.009  MeV . These results supersede our previous measurements published in 2003 and 2012.