# SEMINAR

Three viable models of SM fermion mass generation
*Dr. Antonio Carcamo-Hernandez*
(**Universidad Federico Santa Maria**)

**Sala 2.8.3, IST, Dept. de FĂsica**

**Thursday, October 19th, 2017 at 04:30 PM**

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**Abstract**
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In the first part of my talk I will discuss the first model for radiatively generating the hierarchy of the Standard Model (SM) fermion masses: tree-level top quark mass; 1-loop bottom, charm, tau and muon masses; 2-loop masses for the light up, down and strange quarks as well as for the electron; and 4-loop masses for the light active neutrinos. That model is based on a softly-broken S3xZ2 discrete symmetry and has a scalar sector that consists only of the SM Higgs doublet and three electrically neutral SM-singlet scalars. The model features a viable scalar dark matter candidate.
The second part of my talk is devoted to the discussion of a predictive SU(3)CxSU(3)LxU(1)X (3-3-1) model with A4 family symmetry, consistent with the low energy fermion flavor data. In that model, the observed pattern of SM charged fermion masses and quark mixing angles arises from a Froggatt-Nielsen mechanism, whereas the light active neutrino masses are generated from a one loop level radiative inverse seesaw mechanism.
In the third part of my talk, I will discuss the first renormalizable extension of the 3-3-1 model, which explains the SM fermion mass hierarchy by a sequential loop suppression: tree level top and exotic fermion masses, 1 loop bottom, charm, tau and muon masses; 2-loop masses for the light up, down, strange quarks as well as for the electron; while the light active neutrino masses are generated from a combination of linear and inverse seesaw mechanisms at two loop level. The SU(3)CxSU(3)LxU(1)X gauge symmetry is extended by Z2xZ4 symmetries, which are spontaneously and softly broken, respectively. The model successfully explains the observed SM fermion mass and mixing pattern and has viable scalar dark matter candidates.
This talk is based on the works arXiv:1611.09797, arXiv:1705.05246 and arXiv:1705.09169. `

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