Equation of state in two-, three-, and four-color QCD at nonzero temperature and density
Abstract
We calculate the equation of state at nonzero temperature and density from first principles in two-, three-, and four-color QCD with two fermion flavors in the fundamental and two-index, antisymmetric representation. By matching low-energy results (from a "hadron resonance gas") to high-energy results from (resummed) perturbative QCD, we obtain results for the pressure and trace anomaly that are in quantitative agreement with full lattice-QCD studies for three colors at zero chemical potential. Our results for nonzero chemical potential at zero temperature constitute predictions for the equation of state in QCD-like theories that can be tested by traditional lattice studies for two-color QCD with two fundamental fermions and four-color QCD with two two-index, antisymmetric fermions. We find that the speed of sound squared at zero temperature can exceed 1 /3 , which may be relevant for the phenomenology of high-mass neutron stars.
- Publication:
-
Physical Review D
- Pub Date:
- July 2015
- DOI:
- 10.1103/PhysRevD.92.014019
- arXiv:
- arXiv:1412.6712
- Bibcode:
- 2015PhRvD..92a4019G
- Keywords:
-
- 21.65.Qr;
- 12.39.-x;
- 12.38.-t;
- Quark matter;
- Phenomenological quark models;
- Quantum chromodynamics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Lattice;
- Nuclear Theory
- E-Print:
- 16 pages, 8 figures