  Critical behaviors of quark-hadron phase transition in high-energy heavy-ion
collisions are investigated with the aim of identifying hadronic observables.
The surface of the plasma cylinder is mapped onto a 2D lattice. The Ising model
is used to simulate configurations corresponding to cross-over transitions in
accordance to the findings of QCD lattice gauge theory. Hadrons are formed in
clusters of all sizes. Various measures are examined to quantify the
fluctuations of the cluster sizes and of the voids among the clusters. The
canonical power-law behaviors near the critical temperature are found for
appropriately chosen measures. Since the temperature is not directly
observable, attention is given to the problem of finding observable measures.
It is demonstrated that for the measures considered the dependence on the
final-state randomization is weak. Thus the critical behavior of the measures
proposed is likely to survive the scattering effect of the hadron gas in the
final state.
