3 two matched lattices to be -0.85(17) ( g ) and 0.042(9) ( q ) (these errors are not included in Fig. 2). Fig. 2 shows that for µ < ∼ µ$_{Q}$ the contribution of both quarks and gluons to T$_{µµ}$ is initially positive and in- creasing with µ ; here both quarks and gluons are con- tained within tightly-bound non-relativistic bosons, im- plying that ε > 3 p . For µ > ∼ µ$_{Q}$ , however, their be- haviour diverges sharply (see inset), which could possibly be explained by quark and gluon degrees of freedom now being governed by differing quantum statistics. In fact, the gluon data are very well approximated over the whole µ -range by a parabola, and ( T$_{µµ}$ )$_{g}$ accordingly becomes negative for µ > ∼ µ$_{D}$ . This change in sign has also been predicted using χ PT and the property of asymptotic free- dom [7] (another way of understanding the necessity for ( T$_{µµ}$ )$_{g}$ to change sign is that the plaquette must revert to its quenched value in the limit µ → ∞ where quantum corrections due to quarks are Pauli-blocked [6]). At the same point there is a very sharp change in the behaviour of ( T$_{µµ}$ )$_{q}$, which had been approximately constant for µ$_{Q}$ < ∼ µ < ∼ µ$_{D}$ . Fig. 2 shows that at large µ the quark contribution dominates, so that lim$_{µ}$$_{→∞}$ T$_{µµ}$ > 0. This behaviour is not predicted by χ PT (eg. Eqn. (5) and Ref. [7]), although the positivity of T$_{µµ}$ in this limit is consistent with three-loop perturbation theory [8]. in of degenerate matter then we identify a BEC/BCS crossover at µ$_{Q}$ ≈ 530MeV, corresponding to a quark density n$_{q}$ ≈ 4 − 5fm − $^{3}$, ie. roughly 10 times nuclear density. In order to specify these numbers with greater precision, as well as the statistical errors manifest in the error bars of Fig. 1 we need to establish control over lat- tice artifacts by taking the continuum limit a → 0. So far we have data from only two lattice spacings; results for n$_{q}$/n$_{SB}$ taken with a = 0 . 23fm plotted in Fig. 1 show that there is reasonable scaling for µ < ∼ 400MeV – in- deed, the small difference in the physical j between the two ensembles has maximal impact for µ ≈ µ$_{o}$ [5, 6]. The situation at larger µ will be discussed further below. In contrast to χ PT, the quark contribution to the en- ergy density ε$_{q}$ exceeds the free field value by almost a factor of 20 for µ > ∼ µ$_{o}$ , as shown in the inset of Fig. 1; it should be remarked here that unlike n$_{q}$ and p , ε is sub- ject to a multiplicative quantum correction known as a Karsch coefficient [12] which is still to be calculated for this system, though its renormalised value is unlikely to differ by more than 50%. In any case, since the Karsch coefficient is µ -independent, the shape of the curve will remain the same. Because of this unexpected behaviour at small µ , the energy per quark ε$_{q}$/n$_{q}$ exhibits a shallow but robust minimum for µ > µ$_{Q}$ , a feature completely absent in the model governed by Eqns. (2-6). Fig. 2 plots the conformal anomaly T$_{µµ}$ = ( T$_{µµ}$ )$_{g}$ + ( T$_{µµ}$ )$_{q}$, with where LCP denotes the beta-function is determined along a line of constant physics, and once again a vac- uum contribution must be subtracted. The required beta-functions are estimated from the parameters of the ( T$_{µµ}$ )$_{g}$ = − a ∂β $_{∂a}$∣ ∣ LCP × 3 β N$_{c}$ Tr 〈 ✷$_{t}$ + ✷$_{s}$ 〉 ; (10) ( T$_{µµ}$ )$_{q}$ = a ∂κ $_{∂a}$∣ ∣ LCP × κ − $^{1}$(4 N$_{f}$ N$_{c}$ − 〈 ¯ ψψ 〉 ) , (11) ε$_{g}$ = 3 β N$_{c}$ Tr 〈 ✷$_{t}$ − ✷$_{s}$ 〉 (12) FIG. 3: (Color online) Gluon energy density ε$_{g}$/µ 4 versus µ . Next consider the gluonic energy density given by (once again, a µ -independent Karsch coefficient is still to be determined). Fig. 3 plots the dimensionless com- bination ε$_{g}$/µ 4 against µ ; of course this quantity is not predicted either in χ PT or the free quark gas. While we therefore have no quantitative theory of the gluonic con- tribution to QC 2 D thermodynamics at µ = 0, we would expect its relative importance to increase across a decon- fining transition. In fact, the ratio is remarkably constant