  We explore the formation of diquark molecules and their Bose-Einstein
condensation (BEC) in the phase diagram of three-flavor quark matter at nonzero
temperature, T, and quark chemical potential, mu. Using a quark model with a
four-fermion interaction, we identify possible diquark excitations as poles of
the microscopically computed diquark propagator. The quark masses are obtained
by solving a dynamical equation for the chiral condensate and are found to
determine the stability of the diquark excitations. The stability of diquark
excitations is investigated in the T-mu plane for different values of the
diquark coupling strength. We find that bound diquark molecules appear at small
quark chemical potentials at intermediate coupling and that BEC of non-strange
diquark molecules occurs if the attractive interaction between quarks is
sufficiently strong.
