Dmitrii Kouznetsov, Elementary Decay Process
“ Introduction The simplest quantum-mechanical model of the interaction of an atom with the electromagnetic field field, which still allows the spontaneous decay, was suggested a century ago [3] and then widely applied; in particular, to idealized 3-level systems [4] [5] [1] [2] . The original deduction by Weisscopf and Wigner of the rate of decay (and the resulting spectrum of the emitted photons) is rather euristic than rigorous. The Schroedinger equation for the quantum amplitude with excited atom and that with photons allows the solution in terms of generalized functions. ”
