  Studies of the ultrarelativistic collisions of hadrons and nuclei at
different centrality and energy enable to explore the QCD phase diagram in a
wide range of temperature and baryon density. Long-range correlation studies
are considered as a tool, sensitive to the observation of phase transition and
the critical point. In the present work, a Monte Carlo model of proton-proton,
proton-nucleus, and nucleus-nucleus collisions is applied to heavy and light
ion collisions at the cms energy range from a few up to several hundred GeV per
nucleon. The model describes the nuclear collisions at the partonic level
through interaction of color dipoles and takes into account the effects of
string fusion, which can be considered as an alternative to relativistic
hydrodynamics way of describing the collective phenomena in heavy-ion
collisions. The implementing of both the string fusion and the finite rapidity
length of strings allowed to consider the particle production at non-zero
baryochemical potential. We calculated the long-range correlation functions and
correlation coefficients between multiplicities and transverse momentum at
several energies for different colliding systems and obtained predictions for
the experiment.
