We correct 5 typos and add important information for our Phys. Rev. D 83, 094004 (2011) article. The solutions to the equations obtained using QCD sum rules, the results, and the conclusions in our original article are not modified.

We estimate the relative branching ratio of σ to 2π for the decay of the Ψ ′ (2S), which we have found to be a mixed charm and hybrid charmonium meson. The external field method and correlators from a previous calculation are used to estimate these decays. We find the σ to 2π branching ratio for Ψ ′ (2S) to the J/Ψ(1S) decay to be 0.98, in agreement with an experiment at IHEP-BES.