Light hadron spectrum and decay constants in quenched lattice QCD

We present results for light hadrons composed of both degenerate and nondegenerate quarks in quenched lattice QCD. We calculate masses and decay constants using 60 gauge configurations with an $O(a)$-improved fermion action at β=6.2. Using the ρ mass to set the scale we find hadron masses within two to three standard deviations of the experimental values (given in parentheses): m_K*=868_-8⁺⁹ MeV (892 MeV), m_φ=970_-10⁺²⁰ MeV (1020 MeV), mN=820_-60⁺⁹⁰ MeV (938 MeV), m_Δ=1300_-100⁺¹⁰⁰ MeV (1232 MeV), and m_Ω=1650_-50⁺⁷⁰ MeV (1672 MeV). Direct comparison with experiment for decay constants is obscured by uncertainty in current renormalizations. However, for ratios of decay constants we obtain fKf_π=1.20_-2⁺³(1.22) and f_φf_ρ=1.13_-3⁺²(1.22).