Double-Copy Structure of One-Loop Open-String Amplitudes.

Carlos R Mafra,Oliver Schlotterer

doi:10.1103/physrevlett.121.011601

Abstract

In this Letter, we provide evidence for a new double-copy structure in one-loop amplitudes of the open superstring. Their integrands with respect to the moduli space of genus-one surfaces are cast into a form where gauge-invariant kinematic factors and certain functions of the punctures-so-called generalized elliptic integrands-enter on completely symmetric footing. In particular, replacing the generalized elliptic integrands by a second copy of kinematic factors maps one-loop open-string correlators to gravitational matrix elements of the higher-curvature operator R^{4}.

Highlights

Introduction.—Recent investigations of scattering amplitudes revealed a variety of hidden relations between field theories of seemingly unrelated particle content
Their integrands with respect to the moduli space of genus-one surfaces are cast into a form where gauge-invariant kinematic factors and certain functions of the punctures—so-called generalized elliptic integrands—enter on completely symmetric footing
It has been recently discovered that tree-level amplitudes of the open superstring admit a double-copy representation [7] which mimics the field-theory version of the KLT formula [8]: Gauge-theory trees are double copied with moduli-space integrals whose expansion in the inverse string tension α0 suggests an interpretation as scattering amplitudes in effective scalar field theories [9]

Summary

Introduction

Introduction.—Recent investigations of scattering amplitudes revealed a variety of hidden relations between field theories of seemingly unrelated particle content. In this Letter, we provide evidence for a new double-copy structure in one-loop amplitudes of the open superstring. Their integrands with respect to the moduli space of genus-one surfaces are cast into a form where gauge-invariant kinematic factors and certain functions of the punctures—so-called generalized elliptic integrands—enter on completely symmetric footing.

Results

Conclusion