Tidal effects for spinning particles

• Main Authors: Rafael Aoude, Kays Haddad, Andreas Helset
• Format: Article
• Language: English
• Published: SpringerOpen 2021-03-01
• Series: Journal of High Energy Physics
• Subjects: Effective Field Theories; Scattering Amplitudes; Black Holes
• Online Access: https://doi.org/10.1007/JHEP03(2021)097

Abstract Expanding on the recent derivation of tidal actions for scalar particles, we present here the action for a tidally deformed spin-1/2 particle. Focusing on operators containing two powers of the Weyl tensor, we combine the Hilbert series with an on-shell amplitude basis to construct the tidal action. With the tidal action in hand, we compute the leading-post-Minkowskian tidal contributions to the spin-1/2–spin-1/2 amplitude, arising at O $$ \mathcal{O} $$ (G 2). Our amplitudes provide evidence that the observed long range spin-universality for the scattering of two point particles extends to the scattering of tidally deformed objects. From the scattering amplitude we find the conservative two-body Hamiltonian, linear and angular impulses, eikonal phase, spin kick, and aligned-spin scattering angle. We present analogous results in the electromagnetic case along the way.