  The high density effective theory formalism (HDET) is employed to describe
high density QCD with two massive flavors (2SC). The gap equation is derived
and explicitly solved for the gap parameter. The parameters associated to the
pseudo Nambu-Goldstone boson of $U(1)_A$ are evaluated in the limit
$\mu\to\infty$ and $m/\mu$ fixed. In particular we find for the velocity of the
NG boson the relation
$v^2=\sqrt{\mu_1^2-m_1^2}\sqrt{\mu_2^2-m_2^2}/3\mu_1\mu_2$.
