Investigation of Decay Process Psi(2s) right arrow pi^+ pi^- and Branching Ratio Calculation

According to the existing particle data group (pdg) information, the branching ratio for ψ(2s)→ п^+ п^- is(80 ± 5) ×10^-5 [1].two differenet values for this decay namely (0.8±0.8±0.2) × 10^-5 ,0.84 ± 0.55 (+16,_0.35)× 10^are reported by exprementalists. in this pape it is attempted to study ψ-decay process theoretically via feynman diagrams and it is concluded that the only effective way that ψ can decay into п^+ and п^- mesonsis via one photon emission in an electromagnetic process. this conclusion is based upon the fact that color conservationis violated in one-gluon mechanism and charge conjugation is violated in two-gluon mechanism and gparityand isospin is violated in three-gluon mechanism. by presenting the feynman diagram, the branching ratio of ψ-decay is calculated. the calculated value is in good agreement with the recently reported experimental data.