Planar radiation zeros in five-parton QCD amplitudes

TL;DR

This paper demonstrates the existence of planar radiation zeros in 5-parton QCD scattering processes, showing they occur under specific kinematic configurations and can be linked to BCJ relations and MHV formalism, with potential experimental observability.

Contribution

It reveals the existence of planar radiation zeros in 5-parton QCD amplitudes and connects these zeros to BCJ relations and MHV formalism, including non-planar configurations.

Findings

Radiation zeros occur in specific planar kinematic configurations.

Zeros are linked to BCJ relations and MHV formalism.

Potential observability in hadronic collisions via three-jet production.

Abstract

We demonstrate the existence of `planar', or `type-II', radiation zeros in 5-parton QCD scattering processes. That is, the Born amplitudes are shown to completely vanish for particular kinematic configurations, when all the particle 3-momenta lie in a plane. This result is shown to follow particularly simply from the known BCJ relations between the colour-ordered tree amplitudes, and the MHV formalism is used to express the additional kinematic constraint as a relatively simple expression in terms of only rapidity differences between the final-state partons. In addition, we find that zeros exist for non-planar configurations of the final-state partons, but for which the normal `type-I' conditions on the particle four-momenta do not generally apply. We present numerical results and comment on the possibility of observing planar radiation zeros in hadronic collisions, via central exclusive three-jet production.