Lattice study on chiral dynamics of two-color six-flavors QCD

The electroweak symmetry breaking and origin of masses may be attributed to the breakdown of chiral symmetry due to a strong gauge dynamics. Among several candidates of such gauge systems, we focus on two-color QCD with $N_f=6$ massless Dirac fermions in the fundamental representation, and study on whether the dynamics of this gauge system trigger chiral symmetry breaking or not by simulating with Wilson fermions on lattices up to $L/a=32$. We show the result for the quark mass dependence and the volume dependence of some quantities such as the mass of the lightest pseudoscalar meson, decay constant, and give the three evidences supporting the absence of chiral symmetry breaking in the six-flavor theory.