We apply black-box methods, i.e. where the performance of the method does not depend upon initial guesses, to extract excited-state energies from Euclidean-time hadron correlation functions. In particular, we extend the widely used effective-mass met
hod to incorporate multiple correlation functions and produce effective mass estimates for multiple excited states. In general, these excited-state effective masses will be determined by finding the roots of some polynomial. We demonstrate the method using sample lattice data to determine excited-state energies of the nucleon and compare the results to other energy-level finding techniques.
Dynamical electroweak symmetry breaking (DEWSB) has been a viable option for the completion of the standard model for over thirty years. Precision electroweak studies indicate that the new strong interactions that break EW symmetry cannot be a scaled
-up copy of QCD. Building viable models of DEWSB is difficult without a detailed understanding of such non-QCD gauge theories which still confine and break chiral symmetry. We review past difficulties of studying these theories using lattice methods and describe recent progress, focusing on the role of approximate infrared conformal symmetry.
