  We consider in detail the possibility that the Higgs is wholly or partially
excluded from propagating into one otherwise universal extra dimension. This
exclusion of the Higgs from propagating into an otherwise universal extra
dimension violates tree-level Kaluza-Klein number conservation in the Yukawa
interactions. As a consequence, there is inter-mode mixing between fermions.
For example, zero-mode fermions mix with their associated Kaluza-Klein
excitations. This is in contrast to the original universal extra dimensions
scenario, in which conservation of Kaluza-Klein number prohibits such
inter-mode mixing. Inter-mode mixing is especially significant for the top
quark, since its mass (171.4 +/- 2.1 GeV) is approximately one-half the current
Tevatron mass bound (~350-400 GeV) for Kaluza-Klein excitations of quarks
propagating into universal extra dimensions. We compute the effects that mixing
among the zero-modes and lowest-lying Kaluza-Klein excitations has on the
lightest third-generation charge 2/3 quark mass eigenvalue in the non-universal
Higgs model with one otherwise universal extra dimension. Another consequence
of the inter-mode mixing is that the Kaluza-Klein excitations of the fermions
can decay to a zero-mode Higgs and a corresponding zero-mode fermion. As a
result, the pair production of Kaluza-Klein excitations of the top quark would
lead to two zero-mode Higgs bosons plus a zero-mode top quark/anti-quark pair.
We compute the cross section that the non-universal Higgs model contributes to
Higgs production at the Large Hadron Collider. The effect is quite large: For
example, the Kaluza-Klein contribution to Higgs production is comparable to or
larger than the Standard Model contribution, depending on the Higgs mass, for
compactification scales up to about 600 GeV.
