Journal of High Energy Physics (May 2022)

Quantum off-shell recursion relation

  • Kanghoon Lee

DOI
https://doi.org/10.1007/JHEP05(2022)051
Journal volume & issue
Vol. 2022, no. 5
pp. 1 – 32

Abstract

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Abstract We construct off-shell recursion relations for arbitrary loop-level scattering amplitudes beyond the conventional tree-level recursion relations for ϕ 4-theory and the Yang-Mills theory. We define a quantum perturbiner expansion that includes loop corrections from the quantum effective action formalism by identifying the external source. Our method clearly shows how the perturbiner expansion becomes an off-shell current generating function. Instead of using the classical equations of motion in the conventional perturbiner method, we exploit the Dyson-Schwinger equation to derive the quantum off-shell recursion relation to arbitrary order of loop-level scattering amplitudes. We solve the recursion relation and reproduce the results which agree up to one-loop six-point scattering amplitudes for ϕ 4-theory. Furthermore, we construct the recursions for computing loop-level correlation functions by replacing the choice of the external source.

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