It was shown that different mechanisms of perturbation of spontaneous decay
constant: inelastic interaction of emitted particles with particle detector,
decay onto an unstable level, Rabi transition from the final state of decay
(electromagnetic field domination) and some others are really the special kinds
of one general effect - perturbation of decay constant by dissipation of the
final state of decay. Such phenomena are considered to be Zeno-like effects and
general formula for perturbed decay constant is deduced.Comment: LaTeX 2.09 file, 11 pages, no figures. Accepted in Physics Letters
