Perturbative thermodynamics at nonzero isospin density for cold QCD

We use next-to-leading order in perturbation theory to investigate the effects of a finite isospin density on the thermodynamics of cold strongly interacting matter. Our results include nonzero quark masses and are compared to lattice data.

Figure 1

Cartoon of the phase diagram of QCD at finite temperature and isospin chemical potential based on results from Refs. [14, 28].

Figure 2

Comparison of the ratio of energy density to ${(\text{isospin density})}^{4/3}$ versus the isospin density with lattice results from Ref. [26].

Figure 3

Comparison of the isospin chemical potential versus the isospin density with lattice results from Ref. [26].

Figure 4

Energy density normalized by the isospin-related Stefan-Boltzmann (SB) form versus ${\mu }_I/m_{\pi }$. Lattice results from Ref. [26].

Figure 5

Rescaled energy density by an isospin-related factor of 16 (see text for details) versus ${\mu }_I/m_{\pi }$. The pQCD results approach the SB limit related to the quark chemical potential for two flavors as the strange quark is not appearing in the calculation.

Figure 6

Equation of state compared to the ideal case.