Isospin breaking in image decays I: strong isospin breaking Original Research Article

The CP conserving amplitudes for the decays image are calculated in Chiral Perturbation Theory. The calculation is made at the next-to-leading order including strong and local electromagnetic isospin breaking. A comparison is made between the squared amplitudes with and without isospin violation to estimate the size of the effect. We find corrections of order five percent in the amplitudes.