Ginzburg-Landau phase diagram for dense matter with axial anomaly, strange quark mass, and meson condensation

Understand

We discuss the phase structure of dense matter, in particular the nature of the transition between hadronic and quark matter.

• Calculations within a Ginzburg-Landau approach show that the axial anomaly can induce a critical point in this transition region.
• This is possible because in three-flavor quark matter with instanton effects a chiral condensate can be added to the color-flavor locked (CFL) phase without changing the symmetries of the ground state.
• In (massless) two-flavor quark matter such a critical point is not possible since the corresponding color superconductor (2SC) does not break chiral symmetry.