2017/03/31 by Diego Medrano Jimenez, Diego Medrano Jiménez, A. Sabio Vera +3
Mathematics · Physics and Astronomy · #Amplitude #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Field (mathematics) #Gauge theory #Geometry #Gravitation #Graviton #Mathematical physics #Mathematics #Particle physics theoretical and experimental studies #Physics #Planar #Pure mathematics #Quantum electrodynamics #Quantum mechanics #Scattering amplitude #Stereographic projection #hep-ph #hep-th
paper · pdf · doi:10.1007/jhep05(2017)011
published as JHEP 1705 (2017) 011 · 39 page, 5 figures. v2: typos corrected. It matches the version published in Journal of High Energy Physics
openalex publication_date 2017/05/01 · arxiv created 2017/05/04 · arxiv updated 2017/05/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the projective properties of planar zeros of tree-level scattering amplitudes in various theories. Whereas for pure scalar field theories we find that the planar zeros of the five-point amplitude do not enjoy projective invariance, coupling scalars to gauge fields gives rise to tree-level amplitudes whose planar zeros are determined by homogeneous polynomials in the stereographic coordinates labelling the direction of flight of the outgoing particles. In the case of pure gauge theories, this projective structure is generically destroyed if string corrections are taken into account. Scattering amplitudes of two scalars with graviton emission vanish exactly in the planar limit, whereas planar graviton amplitudes are zero for helicity violating configurations. These results are corrected by string effects, computed using the single-valued projection, which render the planar amplitude nonzero. Finally, we discuss how the structure of planar zeros can be derived from the soft limit behavior of the scattering amplitudes.