Repository logo
 

Natural selection rules: new positivity bounds for massive spinning particles

Published version
Peer-reviewed

Change log

Authors

Davighi, J 
You, T 

Abstract

We derive new effective field theory (EFT) positivity bounds on the elastic 2→2 scattering amplitudes of massive spinning particles from the standard UV properties of unitarity, causality, locality and Lorentz invariance. By bounding the t derivatives of the amplitude (which can be represented as angular momentum matrix elements) in terms of the total ingoing helicity, we derive stronger unitarity bounds on the s- and u-channel branch cuts which determine the dispersion relation. In contrast to previous positivity bounds, which relate the t-derivative to the forward-limit EFT amplitude with no t derivatives, our bounds establish that the t-derivative alone must be strictly positive for sufficiently large helicities. Consequently, they provide stronger constraints beyond the forward limit and can be used to constrain dimension-6 interactions with a milder assumption about the high-energy growth of the UV amplitude.

Description

Keywords

Effective Field Theories, Scattering Amplitudes

Journal Title

Journal of High Energy Physics

Conference Name

Journal ISSN

1029-8479
1029-8479

Volume Title

2022

Publisher

Springer Science and Business Media LLC
Sponsorship
EPSRC (EP/T017481/1)