Multiparticle Flux Tube S-matrix Bootstrap

TL;DR

This paper develops a bootstrap approach for multi-particle scattering of flux tube excitations, deriving bounds that tightly constrain the space of consistent theories, including Yang-Mills flux tubes, through analyticity, crossing, and unitarity principles.

Contribution

It introduces the concept of branon jets and applies the S-matrix bootstrap to flux tube theories, establishing new bounds and revealing a small allowed parameter space.

Findings

Bounds on multi-particle sum rules are derived.

Yang-Mills flux tube lies within a tiny allowed region.

Allowed theories form a small 'island' in theory space.

Abstract

We introduce the notion of branon jets, states of collinear flux tube excitations. We argue for the analyticity, crossing and unitarity of the multi-particle scattering of these jets and, through the S-matrix bootstrap, place bounds on a set of finite energy multi-particle sum rules. Such bounds define a matrioska of sorts with a smaller and smaller allowed regions as we impose more constraints. The Yang-Mills flux tube, as well as other interesting flux tube theories recently studied through lattice simulations, lie inside a tiny island hundreds of times smaller than the most general space of allowed two-dimensional theories.