U_A(1) breaking at finite temperature from the Dirac spectrum with the dynamical HISQ action

Understand

We investigate $U_A(1)$ breaking above $T_c$ in terms of the Dirac spectrum on configurations with (2+1)-flavors, using the HISQ action.

• The strange quark mass is at its physical value.
• We use several light quark masses corresponding to the Goldstone pion masses in the range of about 115 -- 230 MeV on lattices of size 32$^3 \times$8 and 48$^3 \times$8.
• We calculate the 100 lowest-lying Dirac eigenvalues at temperatures below and above $T_c$.