  We analyze the quantum entanglement between opposite spin projection
electrons in the ground state of the Anderson impurity model. In this model, a
single level impurity with intralevel repulsion U is tunnel coupled to a free
electron gas. The Anderson model presents a strongly correlated many body
ground state with mass enhanced quasiparticle excitations. We find, using both
analytical and numerical tools, that the quantum entanglement between opposite
spin projection electrons is a monotonic universal function of the
quasiparticle mass enhancement Z. The mass enhancement, which is used to
quantify the correlations in quantum many body systems, could therefore be used
to quantify spin entanglement.
