Study of the transverse beam tails at LEP

The transverse beam profile in LEP has been studied. Non-Gaussian tails of the distribution have been limiting the maximum current that could safely be collided and are a potential source of backgroun d to the experiments. Scattering processes have been identified as a mechanism which launches particles to large amplitude. Simulations of the relevant scattering processes have been implemented in the tracking code DIMAD. Results from the tracking agree with measurement results for a single beam and for colliding beams with a low beam-beam tune shift. Tail measurements also helped in understandin g the dynamic aperture measurements at LEP.