Contrasting Supersymmetry and Universal Extra Dimensions at the CLIC Multi-TeV e+e- Collider

TL;DR

This paper compares supersymmetry and universal extra dimensions at a future multi-TeV electron-positron collider, proposing methods to distinguish these models through angular distributions, energy spectra, and cross-section measurements.

Contribution

It introduces specific discriminators such as muon angular distributions and photon energy spectra for differentiating supersymmetry from extra dimensions at a linear collider.

Findings

Angular distributions effectively distinguish models.

Energy spectra of radiative photons are discriminative.

Mass determination methods are accurate and feasible.

Abstract

Universal extra dimensions and supersymmetry have rather similar experimental signatures at hadron colliders. The proper interpretation of an LHC discovery in either case may therefore require further data from a lepton collider. In this paper we identify methods for discriminating between the two scenarios at the linear collider. We study the processes of Kaluza-Klein muon pair production in universal extra dimensions in parallel to smuon pair production in supersymmetry, accounting for the effects of detector resolution, beam-beam interactions and accelerator induced backgrounds. We find that the angular distributions of the final state muons, the energy spectrum of the radiative return photon and the total cross-section measurement are powerful discriminators between the two models. Accurate determination of the particle masses can be obtained both by a study of the momentum spectrum of the final state leptons and by a scan of the particle pair production thresholds. We also calculate the production rates of various Kaluza-Klein particles and discuss the associated signatures.