127,913 research outputs found
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
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