The fate of axial U(1) in 2+1 flavor QCD towards the chiral limit

Understand

The region of the Columbia plot with two light quark flavors is not yet conclusively understood.

• Non-perturbative effects, e.g.
• the magnitude of the anomalous U(1) axial symmetry breaking, decides on the nature of the phase transition in this region.
• We report on our study of this region of the Columbia plot using lattice techniques.