  Event-by-event fluctuations of hadronic patterns in heavy-ion collisions are
studied in search for signatures of quark-hadron phase transition. Attention is
focused on a narrow strip in the azimuthal angle with small $\Delta y$. The
fluctuations in the gaps between particles are quantified by simple measures. A
scaling exponent $\alpha$ is shown to exist around $T_c$. An index $\xi$ is
shown to characterize the critical fluctuation; it is a numerical constant
$\xi=0.05\pm0.01$. All the measures considered in this gap analysis are
experimentally observable. Whether or not the theoretical predictions, based on
simulations using 2-dimensional Ising model, are realistic for heavy-ion
collisions, analysis of the experimental data suggested here should be carried
out, since the existence of a scaling behavior is of interest in its own right.
