Virtual Compton Scattering at Low Energy and the Generalized Polarizabilities of the Nucleon

摘要

Virtual Compton Scattering (VCS)(gamma)p(yields)(gamma)p at low CM energy gives access to the Generalized Polarizabilities of the nucleon. These observables generalize the concept of electromagnetic polarizabilities to the case of a virtual photon. Dedicated VCS experiments have been performed at MAMI, Jefferson Lab and MIT-Bates. The experimental status is reviewed, including analysis methods and physics results. The measurement of absolute (ep(yields) ep(gamma)) cross sections allows the extraction of the two unpolarized VCS structure functions P(sub LL)-P(sub TT)/(epsilon) and P(sub LT), which are combinations of the Generalized Polarizabilities of the proton. Future prospects in the field of VCS at low energy are also presented.