K-3π decay and K20-K10 mass difference on current-current picture

Some consequences of the current-current picture are considered in connection with K-3π decay and the K20-K10 mass difference. It is shown that this picture in boson pole approximation can explain both the decay rates and spectra for the 3π decay modes of K. The K20-K10 mass difference is considered in terms of a boson pole approximation and a two-pion intermediate state. The relevant weak-coupling constants are estimated on the current-current picture. It is shown that the sign of the mass difference (δm=δmK20-δmK10) is positive, which is in agreement with recent experimental indications. The magnitude is somewhat small but it is not excluded by the present experimental situation. © 1964 The American Physical Society.