COMPLETE TREATMENT OF THE TIME EVOLUTION OF A SPONTANEOUSLY DECAYING ATOMIC STATE WITHOUT IGNORING VIRTUAL-TRANSITION EFFECTS

It is shown that the application of a self-consistent projection-operator method, developed recently by the author, makes a complete treatment of the sixty-year old problem of spontaneously decaying atomic state possible. In the present treatment all shortcomings of the Weisskopf-Wigner method (two-level atom, rotating-wave and Markov approximations, and the neglect of the term A2 and the retardation and electron-spin effects) are removed. After introducing a new physical real-transition interaction picture (in which the unobservable interaction of the free electron with the vacuum radiation field is eliminated), leading to a natural solution of the renormalization problem, explicit finite analytic results for the whole time evolution in the case of the Lyman-alpha spontaneous emission are obtained.