On-shell representation and further instances of the 2-split behavior of amplitudes

TL;DR

This paper presents a method to obtain on-shell representations of split scattering amplitudes across various theories, demonstrating the universal nature of the 2-split behavior and extending transmuting operators to higher-derivative theories.

Contribution

It introduces a way to derive on-shell split amplitudes in different theories, avoiding current ambiguities and confirming the universality of the 2-split behavior.

Findings

2-split behavior verified in gauge and gravity theories with higher-dimensional operators

On-shell representations obtained without ambiguity in current definitions

Transmuting operators generalized to higher-derivative theories

Abstract

The newly discovered splitting behavior of tree-level scattering amplitudes of particles and strings has been expressed in terms of currents containing one off-shell leg. In this work, we explain how to obtain on-shell representations of the split amplitudes in different theories, thereby avoiding any ambiguity involved in the definition of the currents. Furthermore, we show that this 2-split behavior is also verified in gauge and gravity theories involving higher-dimensional operators, thereby providing additional evidence to its universal character. As a byproduct, we also generalize the transmuting operators to amplitudes in higher-derivative theories.