LHC Constraints on Resonant Kaluza-Klein Gravitons

Abstract

The signature prediction of extra-dimensional theories is the appearance of a tower of massive gravitons. In this work, we study the constraints on resonant heavy spin-2 particles at the Large Hadron Collider (LHC), with focus on the entire tower of gravitons, beyond the traditional single-resonance analysis. Since several states of the tower can lie within the same accessible mass window, the combined signal is enhanced, and the resulting constraints can be significantly stronger than those obtained from a single resonance alone. We first update the current constraints on single graviton searches stemming from diphoton and dilepton data from ATLAS and CMS, using datasets collected above $\sim 200\,{\rm GeV}$, and then consider the impact on the bounds of the full tower of states for different extra-dimensional scenarios. This allows us to extend the reach of current searches to lower mass regions than typically considered, paving the way for future analyses by experimental collaborations.