QSES's and the Quantum Jump

The stochastic methods in Hilbert space have been used both from a fundamental and a practical point of view. The result we report here concerns only the idea of applying these methods to model the evolution of quantum systems and does not enter into the question of their fundamental or practical status. It can be easily stated as follows: Once a quantum stochastic evolution scheme is assumed, the incompatibility between the Markov property and the notion of quantum jump is rapidly established.Comment: LaTeX2e, 3 pages, no figures. Included in the Proceedings of the 3rd Workshop on Mysteries, Puzzles and Paradoxes in Quantum Mechanics, Gargnano, Italy, September 17-23, 200