# Haag-Ruelle scattering theory in presence of massless particles

December 20, 2004

Within the framework of local quantum physics we construct a scattering
theory of stable, massive particles without assuming mass gaps. This extension
of the Haag-Ruelle theory is based on advances in the harmonic analysis of
local operators. Our construction is restricted to theories complying with a
regularity property introduced by Herbst. The paper concludes with a brief
discussion of the status of this assumption.

Keywords:

scattering theory, massless models, Haag-Ruelle theory