Particle yield fluctuations and chemical nonequilibrium in Au-Au collisions at $\sqrt{s_NN}$ = 200 GeV

We study particle yield fluctuations within the statistical hadronization model, considering both chemical equilibrium and non-equilibrium. Considering both the particle yield ratios and the yield fluctuations we show that it is possible to differentiate the chemical freeze-out conditions. As an example of the procedure we consider the relative yield ratio $\Lambda/K^-$ together with the normalized net charge fluctuation $\ave{\Delta Q^2}/\ave{\Nch}$. We determine quantitatively how these variables constrain the chemical conditions at freeze-out.