DPF - PHENO 2024

Equivalence theorems for KK gravitons in warped five-dimensional theories

16 May 2024, 14:30

15m

David Lawrence Hall 106 (University of Pittsburgh)

Other BSM Physics Beyond the Standard Model

Speaker

Xing Wang (UC San Diego)

Description

In this talk, I will discuss how the residual five-dimensional diffeomorphism symmetries of compactified gravitational theories with a warped extra dimension imply Equivalence theorems which ensure that the scattering amplitudes of helicity-0 and helicity-1 spin-2 Kaluza-Klein states equal (to leading order in scattering energy) those of the corresponding Goldstone bosons present in the `t-Hooft-Feynman gauge. We derive a set of Ward identities that lead to a transparent power-counting of the scattering amplitudes involving spin-2 Kaluza-Klein states. Power-counting for the Goldstone boson interactions establishes that the scattering amplitudes grow no faster than $\mathcal{O}(s)$, explaining the origin of the behavior previously shown to arise from intricate cancellations between different contributions to these scattering amplitudes in unitary gauge. Enabled by the Ward identities, I will also describe a robust method for computing the scattering amplitudes without large cancellations among the different diagrammatic contributions. I will also discuss how our results apply to more general warped geometries, including models with a stabilized extra dimension.

Presentation materials

Pheno2024_XingWang.pdf