Massive Scattering Amplitudes in Six Dimensions

TL;DR

This paper develops a spinor-helicity formalism for massive scattering amplitudes in six dimensions, enabling the calculation of amplitudes for particles with arbitrary spin and mass, and explores their high-energy behavior and recursion relations.

Contribution

It introduces a novel spinor-helicity formalism in six dimensions for massive particles, allowing systematic computation of scattering amplitudes with arbitrary spins and masses.

Findings

Fixed 3- and 4-point amplitudes for arbitrary masses and spins.

Analyzed high energy limits and Higgs mechanism within this formalism.

Made preliminary observations on massive BCFW recursion.

Abstract

We show that a natural spinor-helicity formalism that can describe massive scattering amplitudes exists in $D=6$ dimensions. This is arranged by having helicity spinors carry an index in the Dirac spinor {\bf 4} of the massive little group, $SO(5) \sim Sp(4)$. In the high energy limit, two separate kinds of massless helicity spinors emerge as required for consistency with arXiv:0902.0981, with indices in the two $SU(2)$'s of the massless little group $SO(4)$. The tensors of ${\bf 4}$ lead to particles with arbitrary spin, and using these and demanding consistent factorization, we can fix $3-$ and $4-$point tree amplitudes of arbitrary masses and spins: we provide examples. We discuss the high energy limit of scattering amplitudes and the Higgs mechanism in this language, and make some preliminary observations about massive BCFW recursion.