Dispersion relation formalism for virtual Compton scattering and the generalized polarizabilities of the nucleon - art. no. 052201

A dispersion relation formalism for the virtual Compton scattering (VCS) re action on the proton is presented, which for the first time allows a disper sive evaluation of four generalized polarizabilities at a four-momentum tra nsfer Q(2)less than or equal to0.5 GeV2. The dispersive integrals are calcu lated using a state-of-the-art pion photo- and electroproduction analysis. The dispersion formalism provides a new tool to analyze VCS experiments abo ve pion threshold, thus increasing the sensitivity to the generalized polar izabilities of the nucleon.