QCD at small nonzero quark chemical potentials - art. no. 034007

We study the effects of small chemical potentials associated with the three light quark flavors in QCD. We use a low-energy effective field theory tha t solely relies on the symmetries of the QCD partition function. We find th ree different phases: a normal phase, a pion superfluid phase and a kaon su perfluid phase. The two superfluid phases are separated by a first order ph ase transition, whereas the normal phase and either of the superfluid phase s are separated by a second order phase transition. We compute the quark-an tiquark condensate, the pion condensate and the kaon condensate in each pha se, as well as the isospin density, the strangeness density, and the mass s pectrum.