Session D5 - Recent Developments in Computational Nuclear Physics.
INVITED session, Saturday afternoon, May 01
Governor's Square 14, Adam's Mark Hotel
Lattice gauge calculations enable an ab initio exploration of QCD. In this talk, I review recent lattice results in hadronic physics, focusing on the computations of the moments of nucleon structure functions and generalized parton distributions (GPD's), and on the spectrum of excited resonances. I begin with an introduction to lattice QCD, outlining some of the theoretical and computational issues in lattice gauge calculations. I then proceed to describe some of the recent advances enabling computations to be performed at realistic values of the quark masses.
Structure functions and GPD's provide insight into the longitudinal and transverse structure of the nucleon, and their measurement is a crucial part of the hadronic physics experimental program. I describe how their moments are accessible to lattice calculation, and present the latest lattice results, studying in particular their dependence on the quark mass. Further insight into the dynamics of QCD is provided by a study of the spectrum. I review recent lattice results for the excited nucleon spectrum, and in particular for the Roper resonance and for the pentaquark, and describe how they might discriminate between different pictures of the nucleon. I conclude with prospects for future calculations.