On the existence of the "classical trajectories" of atoms in the   Stern-Gerlach experiment
  The widely accepted interpretation of the Stern-Gerlach experiment assumes the objective atomic trajectories (the "classical trajectories") in front of the screen. Following this interpretation, we perform an {\it ab initio} analysis of the experiment and conclude that the objective trajectories do not physically exist. The alternative to our conclusion is substantially to change the model of the experiment. 
M. Dugic, M. Arsenijevic, J. Jeknic-Dugic