Hadron Spectroscopy and Structure from Lattice QCD

Lattice QCD is a theoretical tool that allows us to study the nonperturbative regime of QCD directly with full systematic control. The approach is based on regularizing QCD on a finite four-dimensional Euclidean spacetime lattice and is often studied using numerical computations of QCD correlation functions in the path-integral formalism using national-scale supercomputers. To make contact with experimental data, the numerical results are extrapolated to the continuum (with lattice spacing a→0) and infinite-volume (L→∞) limits. When the calculation is done using heavier-than-physical quark masses (to save computational time), one also has to take the m_q→m^phys_q limit. In the past decade, there has been significant progress in the development of efficient algorithms for the generation of ensembles of gauge-field configurations and tools for extracting relevant information from lattice-QCD correlation functions. Lattice-QCD calculations have reached a level where they not only complement, but also guide current and forthcoming experimental programs. In this lecture, we will briefly describe the methodology of lattice calculations on the topics of hadron spectroscopy and structure. (author)