  It is shown that the inclusion of hadronic interactions, and in particular
nuclear potentials, in simulations of heavy ion collisions at the SPS energy
range can lead to obvious correlations of protons. These correlations
contribute significantly to an intermittency analysis as performed at the NA61
experiment. The beam energy and system size dependence is studied by comparing
the resulting intermittency index for heavy ion collisions of different nuclei
at beam energies of $40A$, $80A$ and $150A$ GeV. The resulting intermittency
index from our simulations is similar to the reported values of the NA61
collaboration, if nuclear interactions are included. The observed apparent
intermittency signal is the result of the correlated proton pairs with small
relative transverse momentum $\Delta p_{t}$, which would be enhanced by
hadronic potentials, and this correlation between the protons is slightly
influenced by the coalescence parameters and the relative invariant
four-momentum $q_{inv}$ cut.
