  The mean field theory, in its different hues, form one of the most useful
tools for calculating the single-body physical properties of a many-body
system. It provides important information, like critical exponents, of the
systems that do not yield to an exact analytical treatment. Here we propose an
entanglement mean field theory (EMFT) to obtain the behavior of the two-body
physical properties of such systems. We apply this theory to predict the phases
in paradigmatic strongly correlated systems, viz. the transverse anisotropic
XY, the transverse XX, and the Heisenberg models. We find the critical
exponents of different physical quantities in the EMFT limit, and in the case
of the Heisenberg model, we obtain the Curie-Weiss law for correlations. While
the exemplary models have all been chosen to be quantum ones, classical
many-body models also render themselves to such a treatment, at the level of
correlations.
