Unitarity methods for scattering in two dimensions

TL;DR

This paper applies unitarity-cut methods to compute one-loop 2-to-2 scattering matrices in various two-dimensional models, including supersymmetric and non-supersymmetric integrable theories, revealing insights into their structure.

Contribution

It demonstrates the applicability of unitarity methods to two-dimensional models and provides evidence for cut-constructibility in supersymmetric integrable theories.

Findings

Supersymmetric models are cut-constructible at one loop.

Non-supersymmetric integrable models have missing rational terms interpreted as coupling shifts.

Method successfully computes scattering matrices in complex two-dimensional theories.

Abstract

The standard unitarity-cut method is applied to several massive two-dimensional models, including the world-sheet AdS$_5\times S^5$ superstring, to compute $2\to 2$ scattering S-matrices at one loop from tree level amplitudes. Evidence is found for the cut-constructibility of supersymmetric integrable models, while for models without supersymmetry (but integrable) the missing rational terms can be interpreted as a shift in the coupling.