  We show that the Linear Sigma Model with quarks produces an effective
description of the QCD phase diagram and of the system's equilibrium
distribution properties that deviate from those of the Hadron Resonance Gas
Model. The deviation is due to the inclusion of plasma screening properties,
encoded in the contribution of the ring diagrams and thus to the introduction
of a key feature of plasmas near phase transitions, namely, long-range
correlations. After fixing the model parameters using input from LQCD for the
crossover transition at vanishing chemical potential, we study the location of
the Critical End Point in the effective QCD phase diagram. We use the model to
study baryon number fluctuations and show that in heavy-ion collisions, the CEP
can be located for collision energies $\sqrt{s_{NN}}\sim 2$ GeV, namely, in the
lowest NICA or within the HADES energy domain.
