The 43rd International Symposium on Lattice Field Theory (Lattice 2026)

The fate of $U(1)_A$ symmetry in finite temperature QCD

Jul 28, 2026, 11:30 AM

30m

Colony Ballroom (Room 2203) (Adele H. Stamp Student Union)

Plenary talk QCD at nonzero temperature and density Plenary session

Speaker

Antonio Smecca (INFN - Sezione di Roma Tre)

Description

The $U(1)_A$ symmetry is explicitly broken by the axial anomaly, but it may be effectively restored at finite temperature. Over the years lattice QCD studies presented contradictory evidence as to whether this restoration occurs near the chiral transition temperature. In this talk I will review recent theoretical and numerical developments on the fate of $U(1)_A$ in hot QCD, including results that point to restoration well above the chiral transition. I will present the current status of the field and discuss the open questions that remain.

Presentation materials

AS_U1A.pdf