  The central-arbitrary bin and forward-backward bin multiplicity correlation
patterns for Au+Au collisions at $\sqrt{s_{NN}} $= $7.7-62.4$ GeV are
investigated within a multi-phase transport (AMPT) model. An interesting
observation is that for $\sqrt{s_{NN}} <19.6$ GeV Au+Au collisions, these two
correlation patterns both have an increase with the pseudorapidity gap, while
for $\sqrt{s_{NN}} >19.6$ GeV Au+Au collisions, they decrease. We mainly
discuss the influence of different evolution stages of collision system on the
central-arbitrary bin correlations, such as the initial conditions, partonic
scatterings, hadronization scheme and hadronic scatterings. Our results show
that the central-arbitrary bin multiplicity correlations have different
responses to partonic phase and hadronic phase, which can be suggested as a
good probe to explore the dynamical evolution mechanism of the hot dense matter
in high-energy heavy-ion collisions.
