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One of the main purposes of SHiP experiment is to shed light on neutrino mass generation mechanisms like the so-called seesaw. We consider a minimal type-I seesaw neutrino mass mechanism model with two heavy neutral leptons (right-handed or sterile neutrinos) with arbitrary masses. Extremely high active-sterile mixing angle requires a correlation between the phases of the Dirac neutrino couplings. Actual experimental limits on the half-life of neutrinoless double beta decay 0 ν β β -rate on the active-sterile mixing angle are not significative in constraining the masses or the mixing measurable by SHiP. [ABSTRACT FROM AUTHOR]

Recently the authors of arXiv:hep-ph/0510321 propose a GUT model for fermion masses and mixings with spontaneously broken S3 discrete flavor symmetry, where S3 is the permutation group of three objects. The S3 breaking pattern in the quark sector is not studied and need further investigation. Since in such a model the number of free parameters is greater than the number of experimental observables, an analytical fit of all the parameters is impossible. To go forward with the model building and to deal with this problem we have used a statistical analysis. We have found that S3 is totally broken and the up-type quarks matrix is approximatively diagonal while down-type quarks matrix is not symmetric and it is parametrized by three couplings, gd, $g_L^d$ and $g_3^d$. It has been found that $g_L^d$ is slightly smaller than gd = 1 and it is of order one, while $g_3^d \sim \lambda^3$ where λ is the Cabibbo angle. An analytical study of the dependence of Vcb and Vub from the couplings $g_L^d$ and $g_3^d$ is also presented. [ABSTRACT FROM AUTHOR]

In third quantization the origin of fermion families is easy to understand: the electron field, the muon field and the tau field are identical fields in precisely the same sense as three electrons are identical and indistinguishable particles of a theory of second quantization. In both cases, the permutation of these fields or particles leaves the Lagrangian invariant. One can also extend the concept of family to gauge bosons. This can be obtained through the semidirect product of the gauge group with the group of permutations of n objects. In this paper we have studied the group $E_6^4 \rtimes S_4$. We explain why we have chosen E6 as fundamental gauge group factor and why we start with a model with four gauge boson/fermion families to accommodate and to fit the Standard Model with only three fermion families. We suggest a possible symmetry breaking pattern of $E_6^4 \rtimes S_4$ that could explain quark, lepton and neutrino masses and mixings. [ABSTRACT FROM AUTHOR]