$\theta$-dependence of QCD at Finite Isospin Density

Abstract

We probe the $\theta$-dependence of QCD at finite isospin chemical potential ${\mu }_I$ using the effective chiral Lagrangian approach. The phase diagram in the $\theta$, ${\mu }_I$ plane is constructed and described in detail in terms of chiral and pion condensates. The physics at $\theta \pi$ is investigated in both the normal and superfluid phase. Finally, the behaviour of the gluon condensate at finite ${\mu }_I$ is computed.

Comments: 14 pages, 2 figures