An Overview of Meson-Nuclear Physics

This conference covers an extremely broad range of topics and in just a few pages it is impossible to even touch on all the areas which will be discussed. We have chosen to summarise just one area where there has recently been impressive progress, namely our quantitative understanding of strangeness in the nucleon. We also discuss a couple of examples where theoretical progress is of direct importance for future experiments as well as for the interpretation of hitherto anomalous results. Finally we make some remarks on meson and baryon spectroscopy and the exciting array of new facilities that are coming on-line in the near future.Comment: Invited talk at MENU201

The Pion Cloud: Insights into Hadron Structure

Modern nuclear theory presents a fascinating study in contrasting approaches to the structure of hadrons and nuclei. Nowhere is this more apparent than in the treatment of the pion cloud. As this discussion really begins with Yukawa, it is entirely appropriate that this invited lecture at the Yukawa Institute in Kyoto should deal with the issue.Comment: Invited talk at Yukawa Institute Kyot

Hadron structure after 25 years of QCD

We briefly review the status of our understanding of hadron structure based on QCD. This includes the role of symmetries, especially chiral symmetry, and the insights provided by lattice QCD. The main focus is on baryon structure and especially the nucleon, but this cannot be treated realistically without reference to spectroscopy. Our aim is to highlight recent insights and promising directions for future work.Comment: Invited talk presented at the 16th Int. Conf. on Few Body Problems (Taipei, March 6-10, 2000); 13 pages, 3 figure

QCD and a New Paradigm for Nuclear Structure

We review the reasons why one might choose to seriously re-examine the traditional approach to nuclear theory where nucleons are treated as immutable. This examination leads us to argue that the modification of the structure of the nucleon when immersed in a nuclear medium is fundamental to how atomic nuclei are built. Consistent with this approach we suggest key experiments which should tell us unambiguously whether there is such a change in the structure of a bound nucleon. We also briefly report on extremely promising recent calculations of the structure of nuclei across the periodic table based upon this idea.Comment: Invited talk at HIAS2015 (ANU

Equivalence of pion loops in equal-time and light-front dynamics

We demonstrate the equivalence of the light-front and equal-time formulations of pionic corrections to nucleon properties. As a specific example, we consider the self-energy of a nucleon dressed by pion loops, for both pseudovector and pseudoscalar pion-nucleon couplings. We derive the leading and next-to-leading nonanalytic behavior of the self-energy on the light-front, and show explicitly their equivalence in the rest frame and infinite momentum frame in equal-time quantization, as well as in a manifestly covariant formulation.Comment: 25 pages, 2 figures; typos corrected in Eqs. (A5), (A6), (A8

Deep inelastic scattering from light nuclei

We review recent developments in the study of deep inelastic scattering from light nuclei, focusing in particular on deuterium, helium, and lithium. Understanding the nuclear effects in these systems is essential for the extraction of information on the neutron structure function.Comment: 11 pages, 5 figures; talk given by W. Melnitchouk at the Workshop on Testing QCD through Spin Observables in Nuclear Targets, University of Virginia, April 200