Helicity selection rules and noninterference for BSM amplitudes

Precision studies of scattering processes at colliders provide powerful indirect constraints on new physics. We study the helicity structure of scattering amplitudes in the standard model (SM) and in the context of an effective Lagrangian description of beyond-the-SM (BSM) dynamics. Our analysis rev...

Full description

Saved in:
Bibliographic Details
Published in:Physical review. D 2017-03, Vol.95 (6), Article 065014
Main Authors: Azatov, Aleksandr, Contino, Roberto, Machado, Camila S., Riva, Francesco
Format: Article
Language:English
Subjects:
Amplitudes
Field theory
Helicity
Operators
Scattering
Standard model (particle physics)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Precision studies of scattering processes at colliders provide powerful indirect constraints on new physics. We study the helicity structure of scattering amplitudes in the standard model (SM) and in the context of an effective Lagrangian description of beyond-the-SM (BSM) dynamics. Our analysis reveals a novel set of helicity selection rules according to which, in the majority of 2→2 scattering processes at high energy, the SM and the leading BSM effects do not interfere. In such situations, the naive expectation that dimension-6 operators represent the leading BSM contribution is compromised, as corrections from dimension-8 operators can become equally (if not more) important well within the validity of the effective field theory approach.
ISSN:2470-0010
2470-0029
DOI:10.1103/PhysRevD.95.065014