Evaluation of the $P({\bf E}\vert{\bf C})$

The $P({\bf E}\vert{\bf C})$ characterises the shape of the background and it depends critically on the type of the interaction mechanism. The crucial point for this unfolding procedure is the evaluation of the element $P({\bf E}\vert{\bf C})$. The implicit assumption that MC simulates well the interaction mechanism is, however, well justified from the experimental data as shown, for example, in figure 1.