Nucleon Polarisabilities from Compton Scattering off the One- and Few-Nucleon System

Abstract

These proceedings sketch how combining recent theoretical advances with data from the new generation of high-precision Compton scattering experiments on both the proton and few-nucleon systems offers fresh, detailed insight into the Physics of the nucleon polarisabilities. A multipole-analysis is presented to simplify their interpretation. Predictions from Chiral Effective Field Theory with special emphasis on the spin-polarisabilities can serve as guideline for doubly-polarised experiments below 300 MeV. The strong energy-dependence of the scalar magnetic dipole-polarisability ${\beta }_{M1}$ turns out to be crucial to understand the proton and deuteron data. Finally, a high-accuracy determination of the proton and neutron polarisabilities shows that they are identical within error-bars. For details and a better list of references, consult the given references.

Comments: 10 pages LaTeX2e with 7 figures in 8 .eps files, using graphicx. Invited seminar given at the 26th Course of the International School of Nuclear Physics: Lepton Scattering and the Structure of Hadrons and Nuclei, Erice (Italy), 16th - 24th September 2004. To be published in Prog. Nucl. Part. Phys. 54, No. 2 as part of the proceedings