Unitarity constraints on non-minimal universal extra dimensional model

We examine the unitarity constraints in the gauge and scalar sectors of the non-minimal universal extra dimensional model. We show that some of the tree-level two-body scattering amplitudes in the gauge and scalar sectors do not respect partial wave unitarity. Unitarity analysis of this model leads to an upper bound on the corresponding boundary-localized (BLT) parameter which depends on the maximum number of the Kaluza–Klein (KK) mode considered in the analysis. This upper bound of the relevant BLT parameter decreases with increasing KK-modes. The results are, in effect, independent of the inverse of the compactifiaction radius. The upper bound on BLT parameter also results in a lower bound on the gauge and scalar KK-masses. (paper)