QCD topology and axion's properties from Wilson twisted mass lattice simulations

Understand

We present the results on topological susceptibility and chiral observables in $N_f=2+1+1$ QCD for temperature range $120<T<600$ MeV.

• The lattice simulations are performed with Wilson twisted mass fermions at physical pion, strange and charm masses.
• In high-$T$ region $T\gtrsim 300$ MeV the chiral observables are shown to follow leading order Griffith analyticity, and the topological susceptibility follows a power-law decay as in the instanton dilute gas models.
• The measured topological susceptibility is used to estimate the mass of QCD axion.