Lattice QCD with two dynamical flavors of domain wall fermions

We present results from the first large-scale study of two-flavor QCD using domain wall fermions (DWF), a chirally symmetric fermion formulation which has been proven to be very effective in the quenched approximation. We work on lattices of size ${16}^3\times 32$, with a lattice cutoff of $a^{-1}\approx 1.7\mathrm{GeV}$ and dynamical (or sea) quark masses in the range $m_{\mathrm{strange}}/2\lesssim m_{\mathrm{sea}}\lesssim m_{\mathrm{strange}}$. After discussing the algorithmic and implementation issues involved in simulating dynamical DWF, we report on the low-lying hadron spectrum, decay constants, static quark potential, and the important kaon weak matrix element describing indirect $CP$ violation in the standard model, $B_K$. In the latter case we include the effect of nondegenerate quark masses ($m_s\ne m_u=m_d$), finding $B_K^{\overline{MS}}(2\mathrm{GeV})=0.495(18)$.