U.S.-Japan Joint Seminar: Nuclear Chiral Dynamics

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

0207601 Bernstein This award supports the participation of American scientists in a U.S.-Japan seminar on nuclear chiral dynamics to be held in Honolulu, Hawaii from February 17-20, 2003. The co-organizers are Professor Aron Bernstein at the Massachusetts Institute of Technology and Professor Makoto Oka at the Tokyo Institute of Technology in Japan. The seminar will focus of two general areas. The first is on the structure of the nucleon and its interactions with the Goldstone Bosons. Specific topics include: 1) the deviations of the nucleon and it's first excited state from spherical symmetry as measured in electromagnetic pion production experiments; 2) the polarizabilities of the nucleon as measured in Compton scattering; 3) the question of isospin breaking, caused by the difference of up and down quark masses, in pi N scattering and electromagnetic pion production with polarized targets; and 4) electromagnetic kaon and eta production and scattering from nucleons. Theoretically these are treated by Chiral Perturbation Theory (ChPT) and dynamical meson-exchange models. The second general area to be discussed is the use of effective field theories for the nucleon-nucleon interactions and for few-nucleon physics. Here the experimental basis is much further developed although there are still important new measurements, particularly involving spin degrees of freedom and neutron properties, that need to be further explored. Research topics to be discussed are being actively pursued by theorists and experimentalists in the U.S. and Japan. In the U.S. there are new electromagnetic apparatus and facilities at Bates, Jefferson Lab and LEGS. In Japan there are the new Spring-8 photon facility and the Tohuku University electron ring. The project advances international human resources through the participation of a postdoc and graduate student. Through the exchange of ideas and technology, this project will broaden our base of basic knowledge and promote international understanding and cooperation. The researchers plan to publish proceedings of the seminar on their Web sites.