Meson and baryon masses for light Kogut-Susskind quarks on a large lattice

Abstract

We calculate meson and baryon masses in quenched QCD for the small quark masses of phenomenological interest on a 10 3 × 16 lattice. We use Kogut-Susskind fermions which possess an explicit continuous chiral symmetry. We verify that this chiral symmetry is spontaneously broken and that for the physics involved our lattice is effectively of infinite volume at the quark masses we calculate. We verify m π 2 ∼ m q, which is what one expects for a Goldstone pion. For Λ mom = 200 MeV, which appears to be the consistent scale of quenched QCD, we find m q ≈ 7 MeV and the hadron masses m ϱ = (730 ± 90) MeV, m A1 = (1190 ± 90) MeV, m ϵ = (660 ± 50) MeV and m N = (920 ± 100) MeV. We also extract f π ≈ 134 MeV. In physical units our lattice is 3 fermi across.