Natural selection rules: new positivity bounds for massive spinning particles
Publication Date
2022-02-21Journal Title
Journal of High Energy Physics
Publisher
Springer Berlin Heidelberg
Volume
2022
Issue
2
Language
en
Type
Article
This Version
VoR
Metadata
Show full item recordCitation
Davighi, J., Melville, S., & You, T. (2022). Natural selection rules: new positivity bounds for massive spinning particles. Journal of High Energy Physics, 2022 (2) https://doi.org/10.1007/jhep02(2022)167
Abstract
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 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.
Keywords
Regular Article - Theoretical Physics, Effective Field Theories, Scattering Amplitudes
Identifiers
jhep02(2022)167, 17852
External DOI: https://doi.org/10.1007/jhep02(2022)167
This record's URL: https://www.repository.cam.ac.uk/handle/1810/337558
Rights
Licence:
http://creativecommons.org/licenses/by/4.0/
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