We analyze the neutrino mass spectrum and discuss the extra-dimensional interpretation of a three-site Pati-Salam model which i) unifies all families of quark and leptons, ii) provides a natural description of the Standard Model Yukawa couplings, iii) could account for the recent $B$-physics anomalies. The key feature of the model is a breaking of the Pati-Salam and electroweak gauge symmetries localized on opposite sites, communicated to the other sites in an attenuated manner via nearest-neighbor interactions. We show that in this context gauge-singlet fermions localized on each site, receiving hierarchical Majorana masses, can allow the implementation of an inverse seesaw mechanism leading to light anarchic neutrino masses consistent with data. The continuum limit of this three-site setup has a natural interpretation in terms of a warped extra dimension with three defects, where the required exponential hierarchies can be achieved from $mathcal{O}(1)$ differences in the bulk field masses.
In this paper, we consider a lopsided flavor texture compatible with thermal leptogenesis in partially composite Pati--Salam unification. The Davidson--Ibarra bound $M_{ u R1} gtrsim 10^9$ GeV for the successful thermal leptogenesis can be recast to the Froggatt--Nielsen (FN) charge of the lopsided texture. We found the FN charge $n_{ u1}$ of the lightest right-handed neutrino $ u_{R1}$ can not be larger than a upper bound, $n_{ u1} lesssim 4.5$. From the viewpoint of unification, the FN charges of the neutrinos $n_{ u i}$ should be the same to that of other SM fermions. Then, two cases $n_{ u i} = n_{qi} = (3,2,0)$ and $ n_{ u i} = n_{l i} = (n+1,n,n)$ are considered. Observations of PS model shows that the case of $n=0$, $n_{li} = n_{di} = (1,0,0)$ will be the simplest realization. To decrease the FN charges of these fermions from the GUT invariant FN charges $n_{qi} = (3,2,0)$, we utilize the partial compositeness. In this picture, the hierarchies of Yukawa matrices are a consequence of mixings between massless chiral fermions $f_{L}, f_{R}$ and massive vector fermions $F_{L,R}, F_{L,R}$. This is induced by the linear mixing terms $lambda^{f} bar f_{L} F_{R}$ and $lambda^{f} bar F_{L} f_{R}$. As a result of the partial compositeness, the decreases of FN charges require fine-tunings between mass and Yukawa matrices either for the increases of $lambda^{f, f}$ or for the decreases of $M_{F,F}$. Therefore, the case for $n=2$ and $n_{di} = n_{li} = (3,2,2)$, which requires only increases of FN charges will be appropriate to build a natural model.
We consider a supersymmetric (SUSY) Grand Unified Theory (GUT) based on the gauge group G_PS=SU(4)_C x SU(2)_L x SU(2)_R, which incorporates non-minimal chaotic inflation, driven by a quartic potential associated with the Higgs fields involved in the spontaneous breaking of G_PS. The inflationary model relies on renormalizable superpotetial terms and does not lead to overproduction of magnetic monopoles. It is largely independent of the one-loop radiative corrections and can become consistent with the current observational data on the inflationary observables, with the symmetry breaking scale of G_PS assuming its SUSY value. Within our model, the strong CP and the mu problems of the minimal supersymmetric standard model can be resolved via a Peccei-Quinn symmetry. Moreover baryogenesis occurs via non-thermal leptogenesis realized by the out-of-equilibrium decay of the right-handed neutrinos, which are produced by the inflatons decay. We consider t