Dispersion relations and QCD factorization in hard reactions

TL;DR

This paper investigates the analytical properties of amplitudes in hard exclusive processes, revealing that QCD factorization leads to a subtracted dispersion relation with the D-term as the subtraction constant.

Contribution

It demonstrates that QCD factorization in certain hard processes results in a specific dispersion relation structure involving the D-term.

Findings

QCD factorization yields a subtracted dispersion relation.

The subtraction constant is given by the Polyakov-Weiss D-term.

Provides insight into the analytical structure of hard exclusive amplitudes.

Abstract

We study analytical properties of the hard exclusive process amplitudes. We found that QCD factorization for deeply virtual Compton scattering and hard exclusive vector meson production results in the subtracted dispersion relation with the subtraction constant determined by the Polyakov-Weiss $D$-term.