Spin polarizabilities and polarizabilities of the nucleon studied by free and quasi-free Compton scattering at MAMI (Mainz)

In addition to the E2/M1 ratio of the N->$\mathrm{\Delta }$ transition, the electromagnetic polarizabilities and spin-polarizabilities are important structure constants of the nucleon which serve as sensitive tests of chiral perturbation theory and of models of the nucleon. Recently, these quantities have been investigated experimentally at MAMI (Mainz) by high-precision Compton scattering using hydrogen and deuterium targets, where for the latter the method of quasi-free scattering has been applied.