  We calculate the Meissner screening mass of gluons 4--7 in two-flavor quark
matter at nonzero temperature. To this end, we study the effective potential of
the 2SC/g2SC phases including a vector condensate $<gA_z^6>$ and calculate the
Meissner mass from the potential curvature with respect to $<gA_z^6>$. We find
that the Meissner mass becomes real at the critical temperature which is about
the half of the chemical potential mismatch. The phase diagram of the neutral
two-flavor color superconductor is presented in the plane of temperature and
coupling strength. We indicate the unstable region for gluons 4--7 on the phase
diagram.

High Energy Physics - Phenomenology