Modern amplitude methods: the rise of massive effective field theories
File(s)
Author(s)
Momeni, Arshia
Type
Thesis
Abstract
Scattering amplitude methods are powerful tools to explore novel ideas in Quantum Field Theories and are of great phenomenological importance. These methods are useful across many areas in physics, from constraining the parameter space of low energy effective field theories (EFT) given assumptions about the UV, known as positivity bounds, to relating two different EFTs, known as the double copy. Most of these methods have been applied to EFTs with massless fields. Here, we focus on the application of these two modern amplitude methods to EFTs with massive spinning particles. To demonstrate the power of positivity bounds, we consider specific applications to different EFTs containing interacting massive spin-2 fields. These will determine whether these massive EFTs can have a crossing symmetric, local, unitary, and causal UV completion. An extension of the very well established double copy relation to massive particles is presented. To show the power of this formalism, various examples of massive double copy are explored such as the double copy of massive Yang-Mills and the double copy of topologically massive theories. Our formalism extends the range of applicability of the double copy framework and will guide our future effort to construct and understand massive EFTs.
Version
Open Access
Date Issued
2022-08
Date Awarded
2022-11
Copyright Statement
Creative Commons Attribution NonCommercial ShareAlike Licence
Advisor
Tolley, Andrew
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)