Quantum deformation of the angular distributions of synchrotron   radiation. Emission of particles in the first excited state
  The exact expressions for the characteristics of synchrotron radiation of charged particles in the first excited state are obtained in analytical form using quantum theory methods. We performed a detailed analysis of the angular distribution structure of radiation power and its polarization for particles with spin 0 and 1/2. It is shown that the exact quantum calculations lead to results that differ substantially from the predictions of classical theory. 
V. G. Bagrov, A. N. Bourimova, D. M. Gitman, A. D. Levin
quant-ph hep-th