Event-by-event analysis of heavy ion collisions and thermodynamical fluctuations

An event-by-event analysis of heavy ions collisions is becoming possible with advent of large acceptance detectors. Such analysis can provide dynamical information which cannot be obtained from inclusive spectra. We identify some observables which can be related to the standard theory of thermodynamic fluctuations and which may provide information about the properties of hadronic matter at the freeze-out stage. Among those are fluctuations of "apparent temperature", or the p_t slope, and the population of different bins of the pion momentum distribution.