Nonperturbative enhancement of superloop at strong coupling

TL;DR

This paper investigates the nonperturbative effects of scalar exchanges on superloop amplitudes at strong coupling in planar N=4 SYM, revealing a significant enhancement that parallels classical area contributions.

Contribution

It introduces a resummation of near-massless scalar exchanges in superloop calculations, showing their nonperturbative enhancement at strong coupling.

Findings

Scalar exchanges contribute equally with classical area at strong coupling.

Near-massless scalar exchanges factorize from massive particle exchanges.

Resummation of scalar exchanges reveals nonperturbative enhancement of superloop.

Abstract

We address the near-collinear expansion of NMHV six-particle scattering amplitudes at strong value of 't Hooft coupling in planar maximally supersymmetric Yang-Mills theory. We complement recent studies of this observable within the context of the Pentagon Operator Product Expansion, via the dual superWilson loop description, by studying effects of multiple scalar exchanges that accompany (or not) massive flux-tube excitations. Due to the fact that holes have a very small, nonperturbatively generated mass which is exponentially suppressed in 't Hooft coupling, their exchanges must be resummed in the ultraviolet limit. This procedure yields a contribution to the expectation value of the superloop which enters on equal footing with the classical area, --- a phenomenon which was earlier observed for MHV amplitudes. In all components, the near-massless scalar exchanges factorize from the ones of massive particles, at leading order in strong coupling.