I argue that in addition to the confined and de-confined phase of QCD, there may be a third confined phase of high density baryonic matter which may exist up to energy densities of order $N_c^2$ times that of $Lambda_{QCD}^4$. In the large $N_c$ limit, the three phases are characterized by baryon number density and confinement. The quarkyonic phase consists of a quasi-free fermi gas of quarks and confined mesons and glueballs. I argue this from general considerations in large $N_c$, and also show it explicitly in a Polyakov loop, NJL model. I conjecture possible relationships between chiral symmetry restoration and the quarkyonic phase.

Brookhaven