Scattering amplitudes abandoning virtual particles

TL;DR

This paper demonstrates that scattering amplitudes can be constructed solely from on-shell tree subamplitudes using the Feynman-tree theorem and BCFW recursion, eliminating the need for virtual particles.

Contribution

It introduces a method to compute scattering amplitudes without virtual particles, simplifying calculations and providing new insights into on-shell methods.

Findings

Scattering amplitudes are constructible from on-shell subamplitudes.

The approach applies to a wide class of models at any order in coupling.

Virtual particles are not necessary in the amplitude construction.

Abstract

We emphasize that scattering amplitudes of a wide class of models to any order in the coupling are constructible by on-shell tree subamplitudes. This follows from the Feynman-tree theorem combined with BCFW on-shell recursion relations. In contrast to the usual Feynman diagrams, no virtual particles appear.