Natural selection rules: new positivity bounds for massive spinning particles

A bstract 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 repre...

Full description

Saved in:
Bibliographic Details
Published in:The journal of high energy physics 2022-02, Vol.2022 (2), p.167-49, Article 167
Main Authors: Davighi, Joe, Melville, Scott, You, Tevong
Format: Article
Language:English
Subjects:
Amplitudes
Angular momentum
Causality
Classical and Quantum Gravitation
Conventions
Effective Field Theories
Elementary Particles
Field theory
Helicity
High energy physics
Physics
Physics and Astronomy
Quantum Field Theories
Quantum Field Theory
Quantum Physics
Regular Article - Theoretical Physics
Relativity Theory
Scattering Amplitudes
String Theory
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:A bstract 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 can provide stronger constraints beyond the forward limit which can be used to constrain dimension-6 interactions with a milder assumption about the high-energy growth of the UV amplitude.
ISSN:1029-8479
1029-8479
DOI:10.1007/JHEP02(2022)167