Relative phase between strong and electromagnetic amplitudes in ψ(2S)→0−0− decays

With the known branching ratios of ψ(2S)→π+π− and ψ(2S)→K+K−, the branching ratio of ψ(2S)→K0SK0L is calculated as a function of the relative phase between the strong and the electromagnetic amplitudes of the ψ(2S) decays. The study shows that the branching ratio of ψ(2S)→K0SK0L is sensitive to the relative phase and a measurement of the K0SK0L branching ratio will shed light on the relative phase determination in ψ(2S)→0−0− decays.