Non-Perturbative Study of 16-Flavor QCD

It is well known that the SU(3) gauge theory with the fundamental 16-flavor fermion is governed by a non-trivial infrared fixed point in the 2-loop perturbation theory, while the theory has not been well investigated by non-perturbative lattice gauge simulations. We investigate properties of 16-flavor QCD by lattice simulation with highly improved actions(HISQ/tree) at wide range of the lattice spacing. We present the Polyakov loop in the spatial direction at several values of β at fixed lattice size and fermion mass. From the result we find that the finite size effect might be large at β = 12, where the lattice bare coupling is almost same as the coupling at the perturbative fixed point. We discuss the finite-size hyperscaling of the mass of pseudoscalar meson to estimate the mass anomalous dimension γ, while the results might have large finite size effect. It is encouraging that the estimated γ is consistent with the perturbative value, although our estimate has large uncertainty.