QCD at Finite Isospin Density
Abstract
QCD at finite isospin chemical potential μ_{I} has no fermion sign problem and can be studied on the lattice. We solve this theory analytically in two limits: at low μ_{I}, where chiral perturbation theory is applicable, and at asymptotically high μ_{I}, where perturbative QCD works. At low isospin density the ground state is a pion condensate, whereas at high density it is a Fermi liquid with Cooper pairing. The pairs carry the same quantum numbers as the pion. This leads us to conjecture that the transition from hadron to quark matter is smooth, which passes several tests. Our results imply a nontrivial phase diagram in the space of temperature and chemical potentials of isospin and baryon number.
 Publication:

Physical Review Letters
 Pub Date:
 January 2001
 DOI:
 10.1103/PhysRevLett.86.592
 arXiv:
 arXiv:hepph/0005225
 Bibcode:
 2001PhRvL..86..592S
 Keywords:

 High Energy Physics  Lattice;
 High Energy Physics  Phenomenology;
 Nuclear Theory
 EPrint:
 4 pages, 1 figure, version to appear in PRL