The non-Gaussian fluctuations of conserved quantities, like net baryon number, were proposed recently as a tool for search of the critical end-point of strongly interacting matter. However, studies of the energy dependence of higher-order cumulants of net-protons in A + A collisions at RHIC and SPS have not revealed any convincing evidence of criticality. We argue that in the current analysis the non-dynamical contribution of trivial volume fluctuations are large, and we propose to use the reduced cumulants with the volume of interaction defined for each event.
G. A. Feofilov (Mon,) studied this question.