content_image/370944.jpg content_image/370945.jpg content_image/370947.jpg content_image/370948.jpg content_image/370946.jpg
stronger the smaller the factor ( y α s − y α b ) x$_{l}$v ′ / Λ ′ is. Note the v ′ / Λ ′ suppression due to the A$_{4}$ structure. This suppression makes the RH tau generically more composite ( c$_{τ}$ > − 1 / 2) than naively expected from its mass. What generically implies light leptonic resonances accessible at the LHC, as discussed in section V. The c$_{3}$ − c$_{1}$ difference also controls how the LH zero modes are split between the ζ$_{1}$$_{,}$$_{2}$ and ζ$_{3}$$_{,α}$ multiplets (see [37] for a related discussion). This becomes essential to protect the τ (LFV) couplings to the Z when it is near the IR brane. 

Let us now turn our attention to the neutrino sector. The matrix elements in Eq. (37) satisfy ‖M ν D ‖ ∼ O (TeV) ≪ ‖M ν M ‖ ≲ O ( M$_{Pl}$ ) for natural values of the model parameters. Then, integrating out the heavy RH neutrinos we obtain the standard see-saw type Majorana mass matrix for the LH neutrinos 

<img src='content_image/370944.jpg'>

where we have defined Δ = ϵ 2 s − ϵ 2 t and 2 2 c 2 

<img src='content_image/370945.jpg'>

In the last equality we have used the tree-level matching of the 5D and 4D gauge coupling constants (in the absence of brane kinetic terms) 

with g ≈ 0 . 65 the 4D SU (2)$_{L}$ coupling constant. If we choose c$_{1}$$_{,}$$_{3}$ ≥ 1 $_{2}$, c$_{3}$ > c$_{α}$ , we can take ι$_{α}$ ∼ = ι independent of α and then 

which can be diagonalized by the Harrison-Perkins-Scott matrix [26] 

<img src='content_image/370947.jpg'>

<img src='content_image/370948.jpg'>

<img src='content_image/370946.jpg'>

