  We study forward-backward charge fluctuations to probe the correlations among
produced particles in ultra relativistic heavy ion collisions. We develop a
model that describes the forward-backward dynamical fluctuations and apply it
to interpret the recent PHOBOS data. Within the present model, the dynamical
fluctuations are related to the particle production mechanism via cluster decay
and to long range correlations between the forward and backward rapidity
hemispheres. We argue that with a tight centrality cut, PHOBOS may see a strong
decrease of the dynamical fluctuations. Within the present model, this
deterioration of the correlation among the produced hadrons can be interpreted
as a sign for the production of a hot, dense and interacting medium.
