Large-momentum effective theory

Abstract

It is an art to match partons defined in the infinite-momentum frame to QCD lattice simulations. Large-momentum effective theory relates properties of Feynman's partons to partons of finite momentum, using asymptotic freedom to match the former's properties in the ultraviolet. Finite-momentum partons are then directly matched to nonperturbative QCD quantities. While reviewing recent developments, this article demonstrates its use in extracting physics from $a\phantom{\rule{0}{0ex}}b$ $i\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}o$ lattice calculations.