  We investigate two-quark correlations in hot and dense quark matter. To this
end we use the light front field theory extended to finite temperature $T$ and
chemical potential $\mu$. Therefore it is necessary to develop quantum
statistics formulated on the light front plane. As a test case for light front
quantization at finite $T$ and $\mu$ we consider the NJL model. The solution of
the in-medium gap equation leads to a constituent quark mass which depends on
$T$ and $\mu$. Two-quark systems are considered in the pionic and diquark
channel. We compute the masses of the two-body system using a $T$-matrix
approach.
