Statistical and dynamical fluctuations in heavy ion collisions: Role of conservation laws in event-by-event analysis

The analysis of the statistical and dynamical fluctuations in nucleus-nucle us collisions on an event-by-event basis strongly relies on a comparison wi th specially constructed artificial events where statistical fluctuations a nd kinematical correlations are under control. In this paper, we present a novel, analytical method of constructing reference events based on independ ent emission, modified by the energy/momentum constraint, which can lead to a better understanding of the nature of the observed final-state fluctuati ons. This approach can be easily used in the analysis of other topics in th e heavy ion field (e.g. flow, HBT etc.) allowing more precise measurements.