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Note here that for λ η > 0 and µ 2 η + λ $^{ηχ}$υ 2 χ + λ $^{ηψ}$υ 2 ψ + λ $^{ηϑ}$υ 2 ϑ > 0 the new Higgs doublet get a zero VEV, i.e., υ$_{η}$ = 0. For the equations ∂V /∂ϕ$_{i}$ to be consistent we can force the couplings λ Φ χ 2 , δ Φ ψ s and δ Φ ψ a to vanish. And by forcing δ $^{χϑψ}$, λ Φ χ 3 and δ ψχ to vanish, we obtain ∂V /∂χ$_{2}$$_{,}$$_{3}$ = 0, and in this case ∂V /∂ψ$_{1}$$_{,}$$_{3}$ = 0 are automatically satisfied. Then we left four independent equations for the four unknown parameters v , v$_{χ}$ , v$_{ψ}$ , and v$_{ϑ}$ : 

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There is another generic way to prohibit the problematic interactions terms by separating physically between ( χ, ϑ, ψ ) and (Φ , η ). Here we solve the vacuum alignment problem by extending the model with a spacial extra dimension y , the method was first introduced in Ref. [10]. We assume the fields live on the 4D brane at y = 0 and y = L as shown in Fig. 11. Heavy neutrino masses arise from local operators at y = 0, on the other hand, charged lepton masses and Yukawa neutrino interactions are realized by non-local effects involving both branes. A detailed explanation of this possibility is beyond the scope of this paper. Assuming that the trilinear couplings go to zero ( δ $^{ψ}$, δψχ and δ χϑψ → 0), then the potential 

<img src='content_image/364670.jpg'>

