LHC Missing-Transverse-Energy Constraints on Models with Universal Extra Dimensions

Understand

We consider the performance of the ATLAS and CMS searches for events with missing transverse energy, which were originally motivated by supersymmetry, in constraining extensions of the Standard Model based on extra dimensions, in which the mass differences between recurrences at the same level are generically smaller than the mass hierarchies in typical supersymmetric models.

• We consider first a toy model with pair-production of a single vector-like quark U1 decaying into a spin-zero stable particle A1 and jet, exploring the sensitivity of the CMS alphaT and ATLAS meff analysis to U1 mass and the U1-A1 mass difference.
• For this purpose we use versions of the Delphes generic detector simulation with CMS and ATLAS cards, which have been shown to reproduce the published results of CMS and ATLAS searches for supersymmetry.
• We then explore the sensitivity of these searches to a specific model with two universal extra dimensions, whose signal is dominated by the pair production of quark recurrences, including searches with leptons.