Multiplicity fluctuations and temperature fluctuations

We argue that specific fluctuations observed in high-energy nuclear collisions can be attributed to intrinsic fluctuations of temperature of the hadronizing system formed in such processes and therefore can be described by the same nonextensivity parameter $q$ characterizing Tsallis statistics describing such systems (for $q \to 1$ one recovers the usual Boltzmann-Gibbs approach). It means that $|q-1|$, which is a direct measure of temperature fluctuations, can also be expressed by the observed mean multiplicity, $<N>$, and by its variance, $Var(N)$. This allows to deduce from the experimental data the system size dependence of parameter $q$ with $q = 1$ corresponding to an infinite, thermalized source with a fixed temperature, and with the observed $q > 1$ corresponding to a finite source in which both the temperature and energy fluctuate.