Speaker
Barbara Pasquini
(University of Pavia)
Description
We review the dispersion analysis of deeply virtual Compton scattering and present a dispersive representation of the D-term form factor for hard exclusive reactions.
We use unsubtracted $t$-channel dispersion relations, where
the $t$-channel unitarity relation is saturated with the contribution of two-pion intermediate states, using the two-pion distributions amplitude for the $\gamma^*\gamma\rightarrow \pi\pi$ subprocess
and reconstructing the $\pi\pi\rightarrow N\bar N$ subprocess from available information on pion-nucleon partial-wave helicity amplitudes.
Results for the D-term form factor as function of $t$ as well as at $t=0$ are discussed in comparison with available model predictions and phenomenological parametrizations.
Author
Barbara Pasquini
(University of Pavia)
Co-authors
Prof.
Marc Vanderhaeghen
(University of Mainz)
Prof.
Maxim Polyakov
(Ruhr U., Bochum)
