  We develop a method for detecting the inhomogeneity of the pion-emitting
sources produced in ultra-relativistic heavy ion collisions, through
event-by-event two-pion Bose-Einstein correlations. The root-mean-square of the
error-inverse-weighted fluctuations between the two-pion correlation functions
of single and mixed events are useful observables for the detection. By
investigating the root-mean-square of the weighted fluctuations for different
impact parameter regions people may hopefully determine the inhomogeneity of
the particle-emitting in the coming Large Hadron Collider (LHC) heavy ion
experiments.
