Hadron structure at small momentum transfer

Abstract

Giving three examples, the form factors of the nucleon, the polarisability of the charged pion and the interference of the $S_{11}(1535)$ with the $D_{13}(1520)$ excitation of the nucleon in the $\eta p$-decay channel, it is argued that the hadron structure at low momentum transfer is highly significant for studying QCD.

Comments: 7 pages, 9 figures. Contribution to the International School of Nuclear Physics, 29th Ccourse, "Quarks in Hadrons and Nuclei", Erice, Sicily, 16 - 24 September 2007