The massless S-matrix of integrable $\sigma$-models
High Energy Physics - Theory
2025-02-03 v2 High Energy Physics - Phenomenology
Exactly Solvable and Integrable Systems
Abstract
In contradistinction to the case of massive excitations, the connection between integrability and the tree-level massless scattering matrix of integrable -models is lost. Namely, in well-known 2-d integrable models the tree-level massless S-matrix exhibits particle production and fails to factorise. This is conjectured to happen due to IR ambiguities in the massless tree-level amplitudes. We present a definition of the massless S-matrix which has all the nice properties of integrable theories, there is no particle production and the S-matrix factorises. As an example, we present in detail the case of the principal chiral model (PCM).
Cite
@article{arxiv.2408.03673,
title = {The massless S-matrix of integrable $\sigma$-models},
author = {George Georgiou},
journal= {arXiv preprint arXiv:2408.03673},
year = {2025}
}
Comments
32 pages, minor changes, version published in JHEP