with Note that these profiles are not only flavor diagonal but flavor independent. We can now insert the former expressions in the general Yukawa Lagrangian, Eq. (20), and get the corresponding zero mode mass term with On the other hand, the UV brane term gives a Majorana mass contribution to the three RH neutrinos, so that the total zero mode mass Lagrangian writes with Assuming λ ≈ 1 and R/R ′ ≈ 10 − $^{16}$, the Majorana mass scale is in the range (10 − 2 − 10 − $^{5}$) /R ≈ 10 17 − 10 14 GeV for − 0 . 5 ≤ c$_{2}$ ≤ − 0 . 35. L m is already diagonal for charged leptons (see Eq. (34)). Furthermore, the localization parameters f − c$_{α}$ naturally explain a hierarchical pattern of charged lepton masses. 4 The electron and muon masses are easily obtained with the corresponding zero modes localized towards the UV brane. The tau mass induces some tension that requires c$_{1}$ and c$_{3}$ to be relatively close to 1 / 2, c$_{1}$$_{,}$$_{3}$ ≲ 0 . 6, and the RH tau to be somewhat localized towards the IR brane, c$_{τ}$ ≥ − 1 / 2. This tension is 4 The A 4 symmetry forces the LH charged leptons to share a common localization thus naturally explaining why the mass hierarchy in this sector is smaller than the one in the charge 2 / 3 quark sector [38]. 12 − L m = ¯ e$_{L}$ M e $_{D}$e$_{R}$ + ¯ ν$_{L}$ M ν $_{D}$ν$_{R}$ + 1 2 ν c R M ν $_{M}$ν$_{R}$ + h . c ., (37) M ν M ≡ f 2 − c 2 λR ′ ( R R ′ ) 2 c 2 ˆ θ$_{M}$ . (38) λ ≡ 1 + | y$_{s}$ | $_{2}$v ′ 2 η Λ ′ 2 f 2 − c 2 f 2 − c 1 . (32) − L Y = ¯ e$_{L}$ M e $_{D}$e$_{R}$ + ¯ ν$_{L}$ M ν $_{D}$ν$_{R}$ + h . c ., (33) ( M e $_{D}$)$_{αβ}$ = √$_{3}$$_{g}$$_{5}$$_{v}$$_{H}$$_{x}$$_{l}$ $_{2}$√$_{2}$$_{R}$ v ′ Λ ′ ( R R ′ ) c 3 − c 1 ( y α s − y α b ) f$_{c}$$_{1}$f − c$_{α}$ √ ι$_{α}$ρ$_{α}$ δ$_{αβ}$, (34) ( M ν $_{D}$)$_{αβ}$ = − g$_{5}$v$_{H}$v ′ η $_{2}$√$_{2}$$_{R}$$_{Λ}$$_{′}$ ( y$_{s}$ − y$_{b}$ ) f$_{c}$$_{1}$f − c 2 √$_{λι}$$_{α}$ δ$_{αβ}$. (35) − L M = 1 2 ν ′ c 2 $_{R}$ˆ θ$_{M}$ ν ′ 2 R ∣ R + h . c . (36)