Finite-width effects and subtraction corrections for the A2 → 3π decay

Effects of interference between ρ-meson poles in the different channels and of subtraction terms for the A₂->3π decay are estimated. Goldberg's formula for the interference correction is discussed and tested by numerical calculations. The FDR-FESR (finite dispersion relation-finite-energy sum rules) technique is used to estimate the correction due to the subtraction. It is found that the effect of a finite ρ width and also the subtraction effect lead to small corrections to the decay width.