Radiative large-angle Bhabha scattering in collinear kinematics

The process of large-angle high energy electron-positron scattering with emission of one hard photon almost collinear to one of the charged particles momenta is considered. The differential cross section with radiative corrections due to emission of virtual and soft real photons calculated to a power accuracy is presented. Emission of two hard photons and total expressions for radiative correction are given in leading logarithmical approximation. The latter are illustrated by numeric estimates. A relation of the results with structure function formalism is discussed.Comment: 19 pp, LaTeX, uses epsfig package, 3 eps figs. Some small changes, including more explanations, addition of references and correction of misprints. Final version Accepted for publication, will appear on nuclear Physics B, issue 563 (1,2), cover date of the issue 6 December 199

Michel parameters in radiative muon decay

Radiative muon and tau lepton decays are described within the model-independent approach with the help of generalized Michel parameters. The exact dependence on charged lepton masses is taken into account. The results are relevant for modern and future experiments on muon and tau lepton decays.Comment: 10 pages, typos are corrected, references are update

On higher order radiative corrections to elastic electron-proton scattering

QED radiative corrections to elastic electron-proton scattering at low energies are discussed. Corrections to the electron line and effects due to vacuum polarization are computed. Higher order effects are estimated for the conditions of the experiment on the electric and magnetic proton form factors by A1 Collaboration. Calculations are performed within the next-to-leading approximation. Inclusion of the higher order effects can affect the value of the proton charge radius extracted from the experimental data.Comment: 6 pages, 3 figure