Boundary Localized Terms in Universal Extra-Dimensional Models through a Dark Matter perspective

Understand

In universal extra dimension (UED) models with one compactified extra dimension, a Z_2 symmetry, termed KK-parity, ensures the stability of the lightest Kaluza-Klein particle (LKP).

• This symmetry leads to two fixed points.
• In non-minimal versions of UED boundary-localised terms (BLT) for different fields are included at these fixed points and KK-parity may be violated.
• However, BLTs with same strength at both points induce a new Z_2 symmetry which restores the stability of the LKP.