Vacuum Stability Constraints and LHC Searches for a Model with a Universal Extra Dimension

Abstract

If the new boson is lying in the narrow mass range between 122 - 127 GeV is confirmed to be a Higgs boson, then stability of the electroweak vacuum in a minimal model with a universal extra dimension (mUED) will require a much lower cutoff for the theory than has been envisaged earlier. We show that this low cutoff would lead to important changes in much of the mUED phenomenology studied till now. In particular, prospects for LHC searches for n = 1 states are rather limited, while resonant n = 2 states may go completely undetected. Prospects for detection at the ILC and CLIC are less affected.