  In this paper, we introduce a freeze-out scheme for the dynamical models near
the QCD critical point through coupling the decoupled classical particles with
the order parameter field. With a modified distribution function that satisfies
specific static fluctuations, we calculate the correlated fluctuations of net
protons on the hydrodynamic freeze-out surface. A comparison with recent STAR
data shows that our model calculations could roughly reproduce energy dependent
cumulant $C_4$ and $\kappa \sigma^2$ of net protons through tuning the related
parameters. However, the calculated $C_2$ and $C_3$ with both Poisson and
Binomial baselines are always above the experimental data due to the positive
contributions from the static critical fluctuations. In order to qualitatively
and quantitatively describe the experimental data, the dynamical critical
fluctuations and more realistic non-critical fluctuation baselines should be
investigated in the near future.
