where τ 2 acts on color indices and ϵ$_{ab}$ = − ϵ$_{ba}$ on flavor. The resulting BEC is composed of weakly interacting qq baryons with J P = 0 $^{+}$. For µ ≥ µ$_{o}$ leading-order χ PT predicts a smooth ro- tation of the chiral condensate 〈 ¯ ψψ 〉 into the superfluid condensate 〈 qq 〉 as µ increases [5]. In addition there is a quantitative prediction for quark density: where the parameters µ$_{o}$ and f$_{π}$ suffice to specify χ PT at this order. It is possible to develop the thermodynamics of the system at T = 0 more fully, to extract pressure and energy density [6]: Note that the trace of the stress-energy tensor ( T$_{µµ}$ )$_{χP T}$ < 0 for µ > √$_{3}$$_{µ}$$_{o}$$_{.}$ These model results should be contrasted with those of another paradigm for cold dense matter, namely a de- generate system of weakly interacting (thus presumably deconfined) quarks populating a Fermi sphere up to some maximum momentum k$_{F}$ ≈ E$_{F}$ = µ : In this picture superfluidity arises from condensation of diquark Cooper pairs from within a layer of thickness Δ centred on the Fermi surface; hence Since p$_{SB}$ eventually exceeds p$_{χP T}$ as µ increases, the degenerate system must be the more thermodynamically stable at high density. In fact, since both n$_{q}$ and ε are discontinuous at the point where p$_{SB}$ = p$_{χP T}$ , this naive treatment predicts the resulting deconfining transition is first order [6]. These considerations have motivated us to pursue lat- tice simulations of QC 2 D beyond the BEC regime, using N$_{f}$ = 2 flavors of Wilson fermion. The quark action is Fig. 1 shows results for quark density and pressure as functions of µ , plotted as ratios of the same quan- tities evaluated for free massless quarks on the same lat- tice [6]. In the j → 0 limit the onset is expected at µ$_{o}$a = 0 . 34 corresponding to µ$_{o}$ ≃ 360MeV; the obser- vation of n$_{q}$, p > 0 for µ < µ$_{o}$ is an artifact of working with j = 0. Beyond onset the ratio n$_{q}$/n$_{SB}$ rises to a peak at µ ≈ 400MeV, then falls to a plateau beginning at µ$_{Q}$ ≈ 530MeV, which continues until µ$_{D}$ ≈ 850MeV where it starts to rise again. If following the arguments presented above we associate the plateau with the setting Since Wilson fermions do not have a manifest chi- ral symmetry, we have little to say at this stage about this aspect of the physics, which at high quark density should be of secondary importance for phenomena near the Fermi surface; they do however carry a conserved baryon charge due to the U(1)$_{B}$ symmetry ψ ↦→ e $^{iα}$ψ , ¯ ψ ↦→ ¯ ψe − $^{iα}$. Our initial runs on a 8 3 × 16 lattice with β = 1 . 7, κ = 0 . 178 corresponding to lattice spacing a = 0 . 230(5)fm, m$_{π}$a = 0 . 79(1) and m$_{π}$/m$_{ρ}$ = 0 . 779(4) have been described in [6]. In this Letter we present data from runs on an approximately matched 12 3 × 24 lattice with β = 1 . 9, κ = 0 . 168 corresponding to a = 0 . 186(8)fm, m$_{π}$a = 0 . 68(1) and m$_{π}$/m$_{ρ}$ = 0 . 80(1). The physical scale is set by equating the observed string tension at µ = 0 to (440MeV) $^{2}$. Note that the physical temperature T is approximately 54(1)MeV for the smaller lattice, and 44(2)MeV for the larger. We used a standard HMC al- gorithm – the only novelty is the inclusion of a diquark source term (proportional to j in Eqn.(8)); this mitigates the impact of IR fluctuations in the superfluid regime and also enables the algorithm to change the sign of det M for a single flavor, thus maintaining ergodicity. All results presented here were obtained with ja = 0 . 04; ultimately the physical limit j → 0 must be taken. A conventional Wilson action was used for the glue fields. Further details can be found in [6]. M$_{xy}$ = δ$_{xy}$ − κ ∑ ν [ (1 − γ$_{ν}$ ) e µδ ν 0 U$_{ν}$ ( x ) δ$_{y,x}$ +ˆ ν + (1 + γ$_{ν}$ ) e − µδ ν 0 U † $_{ν}$( y ) δ$_{y,x}$$_{−}$ ˆ ν ] . (9) S = ∑ i =1 , 2 ¯ ψ$_{i}$Mψ$_{i}$ + κj [ ψ tr 2 ( Cγ 5 ) τ 2 ψ 1 − h.c. ] , (8) with n$_{q}$ ( µ ) = 8 N$_{f}$ f 2 $_{π}$µ ( 1 − µ 4 o µ 4 ) , (2) p$_{χP T}$ = ∫ µ µ o n$_{q}$dµ = 4 N$_{f}$f 2 π ( µ 2 + µ 4 o µ 2 − 2 µ 2 o ) ; (3) ε$_{χP T}$ = − p + µn$_{q}$ = 4 N$_{f}$f 2 π ( µ 2 − 3 µ 4 o µ 2 + 2 µ 2 o ) ; (4) ( T$_{µµ}$ )$_{χP T}$ = ε − 3 p = 8 N$_{f}$f 2 π ($_{−}$ µ 2 − 3 µ 4 o µ 2 + 4 µ 2 o ) . (5) n$_{SB}$ = N$_{f}$ N$_{c}$ 3 π 2 µ $^{3}$; ε$_{SB}$ = 3 p$_{SB}$ = N$_{f}$ N$_{c}$ 4 π 2 µ $^{4}$. (6) 〈 qq 〉 ∝ Δ µ $^{2}$. (7) FIG. 1: (Color online) n$_{q}$/n$_{SB}$ and p/p$_{SB}$ vs. µ for QC$_{2}$D. Inset shows ε$_{q}$/ε$_{SB}$ for comparison. 2