On how classical uncertainties might affect the coherence properties of collisions processes, and how to control them

In principle, the quantum coherence properties of any collision experiment should be affected by unavoidable classical uncertainties. However, they seem to produce no observable effect. This mystery can be solved by introducing the concept of "coherence length" which, in addition, provides a way to control and modify the aforementioned quantum properties. Finally, we discuss different methods to achieve a transition between coherent and incoherent collisions, evaluating their strengths and weaknesses.