Light-hadron spectrum in quenched lattice QCD with staggered quarks

Without chiral extrapolation, we achieved a realistic nucleon to ρ-meson mass ratio of $m_N{/m}_{\rho }=1.23\mathrm{}\pm 0.04\mathrm{}\left(\mathrm{stat}\right)\mathrm{}\pm 0.02\left(\mathrm{syst}\right)\mathrm{}$ in our quenched lattice QCD numerical calculation with staggered quarks. The systematic error is mostly from the finite-volume effect and the finite-spacing effect is negligible. The flavor symmetry breaking in the pion and ρ meson is no longer visible. The lattice cutoff is set at $3.63\pm 0.06\mathrm{GeV},$ the spatial lattice volume is $(2.59\mathrm{}\pm 0.05\mathrm{fm}{)}^3,$ and bare quark masses as low as 4.5 MeV are used. Possible quenched chiral effects in the hadron mass are discussed.