First principles calculations of nucleon and pion form factors: Understanding the building blocks of nuclear matter from lattice QCD

Abstract

Lattice QCD is an essential complement to the current and anticipated DOE-supported experimental program in hadronic physics. In this paper we address several key questions central to our understanding of the building blocks of nuclear matter, nucleons and pions. Firstly, we describe progress at computing the electromagnetic form factors of the nucleon, describing the distribution of charge and current, before considering the role played by the strange quarks. We then describe the study of transition form factors to the Delta resonance. Finally, we present recent work to determine the pion form factor, complementary to the current JLab experimental determination and provding insight into the approach to asymptotic freedom. © 2005 IOP Publishing Ltd.