INT  Workshop  on


Institute for Nuclear Theory,  University of Washington,  Seattle

 June 11-16, 2001



Nuclear forces form the basis for our comprehension of nuclear structure and reactions. In the 50 years since the discovery of the pion, progress in understanding the two-nucleon interaction and consistent few-nucleon forces has been slow and difficult. In particular, the connection to the 25-year-old theory of the strong interaction, quantum chromodynamics (QCD), remains an enigma. However, the last few years have witnessed important advances that opened doors to a better understanding of the nuclear force.

Novel partial-wave analysis methods that incorporate the rich two-nucleon database can now be used as a sensitive tool to study small but important effects, such as those stemming from two-pion exchange and isospin violation. These methods have in the past inspired high-quality potentials that almost exactly reproduce the two-nucleon data, but which are not fully in accordance with chiral symmetry.

Few-body calculations are being performed to unprecedent precision and used as a genuine source of information about the nuclear force. In particular, they are now sensitive to both two-pion-exchange and short-range aspects of the three-body force. At the same time, the consistency of electromagnetic currents and the hunt for effects of the three-body force have become important issues in the few-nucleon field. Experiments have already suggested the need for three-body forces; more comprehensive efforts are underway in a number of laboratories.

Finally, an effective field theory (EFT) approach is being developed to allow systematic expansions consistent with QCD. Such an approach incorporates chiral symmetry and overcomes the renormalizability problems encountered in the fifties, removing at the same time the off-shell arbitrariness that plagues few-nucleon calculations to this day. The connections between EFT and potential models are not yet fully clarified, and important features like the most efficient power counting remain to be determined by further confrontation with data.

The workshop will focus on our current understanding of nuclear forces, in particular:

  1. The two-pion exchange component of the two-nucleon force and its relation to low-energy pion-nucleon and pion-pion scattering: implications of chiral symmetry; the role of the Delta isobar; the nature of the ``sigma'' meson.
  2. Short-range aspects of the nuclear force: contact interactions versus bosons; regularization issues.
  3. Few-body constraints on the nuclear force: ab initio calculations of light nuclei and nucleon-deuteron and nucleon-triton scattering; towards consistent three-nucleon interactions and incorporating relativity correctly.
  4. Isospin violation in the nuclear force: strong and electromagnetic effects.
  5. Formulation of consistent meson-exchange currents.


  • B.R. Barrett (Arizona): ``The No-Core Shell-Model Approach and Its Application to Few-Nucleon Systems''
  • S.R. Beane (Washington): ``Perturbative theories of nuclear forces''
  • P.F. Bedaque (LBL)
  • J.A. Carlson (LANL): ``Challenges in Few- to Many-Nucleon Physics''
  • J.-W. Chen (Maryland): ``Calibrating SNO and the Sun''
  • T.D. Cohen (Maryland): ``Systematic Expansions of QCD and Nuclear Physics''
  • D.R. Entem (Idaho)
  • A.C. Fonseca (IFM): ``Four-nucleon scattering: a sensitive theoretical laboratory to study the NN force''
  • J.L. Friar (LANL): ``The Endgame in Traditional Few-Nucleon Physics''
  • R.J. Furnstahl (Ohio State): ``Workshop Summary''
  • B.F. Gibson (Los Alamos)
  • H.W. Griesshammer (Munich): ``Nucleon Properties by Probing the Deuteron at Low Energies''
  • F. Gross (William and Mary): ``Covariant Effective Field Theories''
  • H.-W. Hammer (Ohio State): ``Three-body nuclear physics in EFT''
  • N. Kalantar (KVI): ``Few-Body Physics Activities at KVI''
  • D.B. Kaplan (INT)
  • T. Luu (Washington): ``The Shell Model as an Effective Theory''
  • R. Machleidt (Idaho): ``Developing an accurate NN potential based upon chiral perturbation theory''
  • U.-G. Meissner (Juelich): ``Few-nucleon systems: New results from chiral effective field theory''
  • G.A. Miller (Washington): ``Light-Front Treatment of the NN System''
  • V.R. Pandharipande (Illinois): ``Standard Model of Nuclear Physics: Concept and Prospects''
  • M.T. Pena (IST): ``Meson production and models for three-nucleon forces''
  • D.R. Phillips (Ohio): ``Higher-order chiral perturbation theory calculations of electromagnetic reactions on deuterium''
  • M.J. Savage (Washington): ``m_q Dependence''
  • R. Schiavilla (Old Dominion): ``Nuclear Standard Model versus EFT: a Case Study in Weak Transitions''
  • J. Sowinski (IUCF): ``Few-Nucleon Physics at IUCF: Past, Present and Not Too Much Future''
  • J.J. de Swart (Nijmegen): TBA
  • R.G.E. Timmermans (KVI)
  • W. Tornow (TUNL): ``Unsolved Problems in 2N and 3N Physics from an Experimentalist's Point of View''
  • J.A. Tjon (Utrecht): ``The NN interaction and pp bremsstrahlung''
  • U. van Kolck (Arizona): ``Three-Nucleon Forces''
  • S.J. Wallace (Maryland): ``Equal-time relativistic formalism: bound states, currents and boosts''
  • R.B. Wiringa (ANL): ``Evolution of nuclear spectra from bare two- and three-nucleon forces''
  • (The number of participants is limited to facilitate intense discussion.)

    A schedule exists.

    The INT posts scanned transparencies of all talks presented during its programs or workshops. If you will be speaking during the workshop, please remember to submit your talk either in hardcopy or electronic format.
    Hardcopy submission: Hand in your transparencies to the INT program assistant, Andrea Partel, as soon as possible after you have given your talk. They will be scanned in by the INT staff and posted on our web site. The process usually takes 1-2 days. Please inform Andrea if you are planning to leave within a day or two of giving your talk so that we can try to accommodate your schedule.
    Electronic submission: You can submit your talk in electronic format by email. We currently accept the following formats: 1) Postscript: Either as one big postscript file with all your transparencies on it OR as several separate files, each file with one transparency on it and named,, ... ...; 2) TIFF or pnm: Each transparency as a separate file named 01.TIFF, 02.TIFF ... 10.TIFF ... OR 01.pnm, 02.pnm ... 10.pnm ...
    If you are submitting more than one file please tar and gzip your files together and name the file as: "lastname"_"INT-01-20W".tar.gz

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