Wade Allison

Abstract:

To show that the principle of ionization cooling will work for muon beams we must be able to simulate energy loss and scattering in media reliably. We have three choices: we can use traditional calculations with their uncertainties; we can make measurements (MUSCAT) or, we can calculate the phenomena more carefully, looking afresh at the phenomena from first principles. In this paper we report on work following this third approach. We derive the double differential cross section for a collision with transverse momentum transfer P-t and longitudinal momentum transfer P-l from a knowledge of the UV and x-ray photoabsorption cross section of the medium, together with the known kinematics and dynamics of the scattering of point charges with screening. Distributions in energy loss and scattering may then be found by Monte Carlo techniques which take into account both correlations in scattering and energy loss, and the true effects of non-Gaussian tails in distributions of interest. Preliminary results are reported for molecular hydrogen. Further work is in progress.