# Transverse spectrum of bremsstrahlung in finite condensed media

Feal, X. (Departamento de Física de Partículas & Instituto Galego de Física de Altas Enerxías Universidade de Santiago de Compostela, 15782 Santiago, Spain) ; Vazquez, R. A. (Departamento de Física de Partículas & Instituto Galego de Física de Altas Enerxías Universidade de Santiago de Compostela, 15782 Santiago, Spain)

03 January 2019

Abstract: A formalism is presented in which the radiation of photons off high energy electrons during a multiple scattering process with finite condensed media can be evaluated for a general interaction. We show that the arising Landau-Pomeranchuk-Migdal suppression for finite size targets saturates at some characteristic photon energy. Medium coherence effects in the photon dispersion relation can be also considered leading to a dielectric suppression or transition radiation effects in the soft part of the spectrum. The main results of our formulation are presented for a Debye screened interaction and its well-known Fokker-Planck approximation, showing that for finite size targets or for the angular distributions of the final particles the differences between both scenarios cannot be reconciled into a single redefinition of the medium transport parameter ($\stackrel{^}{q}$). Our predictions are in very good agreement with the experimental data collected at SLAC.

Published in: Physical Review D 99 (2019)