Neutrino masses from an A4 symmetry in holographic composite Higgs models Águila Giménez, Francisco Del Carmona Bermúdez, Adrián Santiago Pérez, José Neutrino physics Field theories in Higher dimensions Discrete and finite symmetries We show that holographic composite Higgs Models with a discrete A 4 symmetry can be built, which naturally predict hierarchical charged lepton masses and an approximate tri-bimaximal lepton mixing with the correct scale of neutrino masses and a characteristic phenomenology. They also satisfy current constraints from electroweak precision tests, lepton flavor violation and lepton mixing in a large region of parameter space. Two features arise in our model phenomenologically relevant. First, an extra suppression on the lepton Yukawa couplings makes the τ lepton more composite than naively expected from its mass. As a consequence new light leptonic resonances, with masses as low as few hundreds of GeV, large couplings to τ and a very characteristic collider phenomenology, are quite likely. Second, the discrete symmetry A 4 together with the model structure provide a double-layer of flavor protection that allows to keep tree-level mediated processes below present experimental limits. One-loop processes violating lepton flavor, like μ → eγ, may be however observable at future experiments. 2014-03-06T13:51:26Z 2014-03-06T13:51:26Z 2010 journal article Águila, F.; Carmona, A.; Santiago, J. Neutrino masses from an A4 symmetry in holographic composite Higgs models. Journal of High Energy Physics, 2010: 127 (2010). [http://hdl.handle.net/10481/30720] 1029-8479 doi: 10.1007/JHEP08(2010)127 arXiv:1001.5151v2 http://hdl.handle.net/10481/30720 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Scuola Internazionale Superiore di Studi Avanzati (SISSA)