The asymptotic behaviour of the ( [formula omitted]p-pp) forward amplitude

Abstract

We have investigated from a new point of view the crossing-odd amplitude F (−) using dispersion relations (DRs). It is shown that the existing data favour clearly asymptotic Regge behaviour which implies the validity of an unsubtracted DR although more complicated asymptotic behaviour involving odderon terms cannot be ruled out presently. Precise Coulomb interference data at ISR energies would constitute a crucial test. The DR applied at threshold leads to a sum rule between the pp and p p scattering lengths on one side and the cross-section data on the other side. It turns out that this sum rule is well satisfied.