Instantons and the anomalous U(1)_A symmetry in high temperature QCD

December 2, 2024
3:00pm to 4:00pm

IFT Seminar Room/Red Room

Theoretical Physics, general interest
Speaker: 
Tamás Kovács
Institution: 
Eötvös U.
Location&Place: 

IFT Seminar Room/Red Room

Abstract: 

I present a new way of understanding how chiral symmetry is realized in the high temperature phase of QCD. I show that a simple instanton model provides an excellent description of the lowest part of the spectrum of the Dirac operator, the part that dominates physical quantities related to chiral symmetry. Remarkably in a strongly interacting theory, this part of the spectrum can be understood in terms of a gas of non-interacting instantons. The model I present also indicates a possible way of resolving a long-standing debate about the fate of the anomalous U(1)_A symmetry at high temperature.