Bose Einstein condensation of pions

Massimo Mannarelli, Gran Sasso Laboratory, L’Aquila, Italy

When the isospin chemical potential exceeds the pion mass, charged pions condense in the zero-momentum state forming a superfluid. We examine various aspects of the pion condensed phase within the chiral perturbation theory framework, deriving an analytic expression for the corresponding equation of state. We compare our results with lattice QCD simulations, showing the excellent agreement between the two approaches in the relevant isospin range.