All Tree Level Scattering Amplitudes in ChernSimons Theories with Fundamental Matter
Abstract
We show that BrittoCachazoFengWitten (BCFW) recursion relations can be used to compute all tree level scattering amplitudes in terms of 2 →2 scattering amplitude in U (N ) N =2 ChernSimons (CS) theory coupled to matter in the fundamental representation. As a byproduct, we also obtain a recursion relation for the CS theory coupled to regular fermions, even though in this case standard BCFW deformations do not have a good asymptotic behavior. Moreover, at large N , 2 →2 scattering can be computed exactly to all orders in 't Hooft coupling as was done in earlier works by some of the authors. In particular, for N =2 theory, it was shown that 2 →2 scattering is tree level exact to all orders except in the anyonic channel [K. Inbasekar et al., J. High Energy Phys. 10 (2015) 176, 10.1007/JHEP10(2015)176], where it gets renormalized by a simple function of 't Hooft coupling. This suggests that it may be possible to compute the all loop exact result for arbitrary higherpoint scattering amplitudes at large N .
 Publication:

Physical Review Letters
 Pub Date:
 October 2018
 DOI:
 10.1103/PhysRevLett.121.161601
 arXiv:
 arXiv:1710.04227
 Bibcode:
 2018PhRvL.121p1601I
 Keywords:

 High Energy Physics  Theory
 EPrint:
 RevTEX 4.1, 5 pages+6 Appendices, 7 figures