Abstract

We use the formulation of conformal higher spin (CHS) theories in twistor space to study their tree-level scattering amplitudes, finding expressions for all three-point MHV¯ amplitudes and all MHV amplitudes involving positive helicity conformal gravity particles and two negative helicity higher spins. This provides the on-shell analogue for the covariant coupling of CHS fields to a conformal gravity background. We discuss the restriction of the theory to a ghost-free unitary subsector, analogous to restricting conformal gravity to general relativity with a cosmological constant. We study the flat-space limit and show that the restricted amplitudes vanish, supporting the conjecture that in the unitary sector the S-matrix of CHS theories is trivial. However, by appropriately rescaling the amplitudes we find non-vanishing results which we compare with chiral flat-space higher spin theories.

Details

Title
Conformal higher spin scattering amplitudes from twistor space
Author
Adamo, Tim 1 ; Hähnel Philipp 2 ; McLoughlin Tristan 2 

 Blackett Laboratory, Imperial College, London, U.K. (GRID:grid.7445.2) (ISNI:0000 0001 2113 8111) 
 School of Mathematics, Trinity College Dublin, Dublin 2, Ireland (GRID:grid.8217.c) (ISNI:0000 0004 1936 9705) 
Publication year
2017
Publication date
Apr 2017
Publisher
Springer Nature B.V.
e-ISSN
10298479
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
1884064395
Copyright
© The Author(s) 2017. This work is published under https://creativecommons.org/licenses/by/4.0 (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.