Finite size effects on the phase diagram and the baryon fluctuations via momentum space constraints

The effect of the finite system size on the QCD phase diagram was studied with various momentum space constraints within a mean-field quark–meson model. On the one hand side, the choice of the scenario – low-momentum cutoff and discretization with periodic or antiperiodic boundary conditions – and the presence of the vacuum fluctuations were found to strongly affect the volume dependence of the CEP. On the other hand, its location is significantly shifted in each case for linear sizes below L ≈ 10 fm. This is also reflected in the conserved charge fluctuations, which were investigated along the phase boundary using multiple scenarios for the finite size effects.