Radiative tail in (pi)(sub e2) decay and some comments to (mu)-e universality

摘要

The results of lowest order of perturbation theory calculations of photon and positron spectra in radiative (pi)(sub e2) decay are generalized to all orders of perturbation theory using the structure functions method. An additional source of radiative corrections to the ratio of positron and muon channels of pion decays, connected with emission of virtual and real photons and pairs is searched. It depends on details of detection of final particles and large enough in magnitude to be taken into account in theoretical estimations on the level of accuracy 0.1%. 4 refs. (Atomindex citation 28:002785)