N* Spectrum in Lattice QCD

Abstract

We investigate the mass of the parity partner $N^{\ast }(1/2^{-})$ of the nucleon $N(1/2^{+})$, in lattice QCD using a new lattice discretization scheme for fermions, domain wall fermions (DWF). DWF possess exact chiral symmetry and flavor symmetry, both of which are required for this problem, even at finite lattice spacing. Our calculation reproduces the large mass splitting between those two states, in good agreement with experiment. We also present preliminary results for the mass of the positive-parity excited state $N^{\prime }(1/2^{+})$.

Comments: Invited talk given at Jefferson Lab Workshop on The Physics of Excited Nucleons (NSTAR2000), Newport News, VA, Feb. 16-19, 2000, Latex, 10 pages, 3 figures