Analysis of $N^{\star}$ spectra using matrices of correlation functions   based on irreducible baryon operators
  We present results for ground and excited-state nucleon masses in quenched lattice QCD using anisotropic lattices. Group theoretical constructions of local and nonlocal straight-link irreducible operators are used to obtain suitable sources and sinks. Matrices of correlation functions are diagonalized to determine the eigenvectors. Both chi-square fitting and Bayesian inference with an entropic prior are used to extract masses from the correlation functions in a given channel. We observe clear separation of the excited state masses from the ground state mass. States of spin >= 5/2 have been isolated by use of G_2 operators. 
LHP Collaboration: S. Basak, I. Sato, S. Wallace (UMD), R. Edwards,   G.T. Fleming, D. Richards (JLab), R. Fiebig (FIU), U.M...