  We derive an effective theory for dense, cold and massive quark matter. To
this end, we employ a general effective action formalism where antiquarks and
quarks far from the Fermi surface, as well as hard gluons, are integrated out
explicitly. We show that the resulting effective action depends crucially on
the projectors used to separate quarks from antiquarks. If one neglects the
quark masses in these projectors, the Feynman rules of the effective theory
involve quark mass insertions which connect quark with antiquark propagators.
Including the quark masses into these projectors, mass insertions do not appear
and the Feynman rules are identical to those found in the zero-mass limit.
