Baxter equation beyond wrapping

TL;DR

This paper develops an improved finite-difference equation for the spectrum of Wilson operators in supersymmetric Yang-Mills theory, accurately capturing effects beyond wrapping order and matching known Bethe Ansatz results.

Contribution

It introduces a self-consistent asymptotic finite-difference equation incorporating nonpolynomial effects, valid at all perturbation orders, extending the Baxter equation beyond wrapping corrections.

Findings

Exact solutions match asymptotic Bethe Ansatz results.

Computed anomalous dimensions for short operators beyond wrapping order.

Validated the improved equation's accuracy at higher perturbation orders.

Abstract

The Baxter-like functional equation encoding the spectrum of anomalous dimensions of Wilson operators in maximally supersymmetric Yang-Mills theory available to date ceases to work just before the onset of wrapping corrections. In this paper, we work out an improved finite-difference equation by incorporating nonpolynomial effects in the transfer matrix entering as its ingredient. This yields a self-consistent asymptotic finite-difference equation valid at any order of perturbation theory. Its exact solutions for fixed spins and twists at and beyond wrapping order give results coinciding with the ones obtained from the asymptotic Bethe Ansatz. Correcting the asymptotic energy eigenvalues by the Luescher term, we compute anomalous dimensions for a number of short operators beyond wrapping order.