  With a substantial amount of simulations, we have explored the system across
a wide range of lattice scales. We have located a lattice artifact, first order
bulk transition, have studied its properties, and found that the flavor-singlet
scalar meson mass vanishes at the critical endpoint. We will discuss the
lattice phase diagrams and the continuum limits for both a spontaneous chiral
symmetry breaking phase and an infrared conformal phase, and compare results
with other groups.
