Five-point spinor-helicity Compton amplitudes in gauge theory and gravity

Abstract

We calculate the five-point tree-level Compton amplitudes for minimally coupled spinning matter in gauge theory and gravity in the massive spinor-helicity formalism, using BCFW recursion and KLT relations. The results are written in terms of symmetrized spinor products and are simultaneously valid for a range of matter spins, which directly generalizes the amplitudes of Arkani-Hamed, Huang, and Huang to the five-point case. Unlike the three- and four-point cases, each amplitude can be a sum of two or more distinct spin structures. Spurious poles are manifestly canceled through a mechanism that holds for all massive spins $s\le 1$ in gauge theory and $s\le 2$ in gravity. While we keep the amplitudes exact, their classical limits are expected to be relevant for binary systems of Kerr black holes in the post-Minkowskian expansion.

67 pages, 42 figures