Eigenvalue distribution of the Dirac operator at finite temperature with (2+1)-flavor dynamical quarks using the HISQ action

We report on the behavior of the eigenvalue distribution of the Diracoperator in (2+1)-flavor QCD at finite temperature, using the HISQ action. Wecalculate the eigenvalue density at several values of the temperature close tothe pseudocritical temperature. For this study we use gauge fieldconfigurations generated on lattices of size $32^3 \times 8$ with two lightquark masses corresponding to pion masses of about 160 and 115 MeV. We findthat the eigenvalue density below $T_c$ receives large contributions fromnear-zero modes which become smaller as the temperature increases or the lightquark mass decreases. Moreover we find no clear evidence for a gap in theeigenvalue density up to 1.1$T_c$. We also analyze the eigenvalue density near$T_c$ where it appears to show a power-law behavior consistent with what isexpected in the critical region near the second order chiral symmetry restoringphase transition in the massless limit.