Related papers: Proton stability from a fourth family
We study in detail the mechanism of baryon and lepton asymmetry generation in the framework of the $\nu$MSM (an extension of the Standard Model by three singlet fermions with masses smaller than the electroweak scale). We elucidate the…
A minimal particle content supersymmetric model with a discrete Z_3 symmetry, allowing lepton number violating terms, is studied. Within this model, the neutrino masses and mixing can be generated by lepton number violating couplings.…
If the standard model of quarks and leptons is extended to include three singlet right-handed neutrinos, then the resulting fermion structure admits an infinite number of anomaly-free solutions with just one simple constraint. Well-known…
We call attention to that if assuming no conserved charges in the fundamental theory with fermions, which carry only a spin and interact with only the gravity, the dimensions $4, 12, 20,.....,$ as well as all odd dimensions, are excluded…
We argue that the fermion masses and mixings are organized in a specific pattern. The approximately equal hierarchies between successive generations, the sizes of the mixing angles, the heaviness of just the top quark, and the approximate…
We discuss F-theory SU(5) GUTs in which some or all of the quark and lepton families are assigned to different curves and family symmetry enforces a leading order rank one structure of the Yukawa matrices. We consider two possibilities for…
Gauged B-L is a popular candidate for the origin of the conservation of R parity, i.e. R = (-)^{3B+L+2j}, in supersymmetry, but it fails to forbid the effective dimension-five terms arising from the superfield combinations QQQL, uude, and…
A conventional graviton vertex operator is generated from the gauging of global supersymmetry. If the outgoing gravitino is replaced by a fermion-boson pair of like helicity, and if a new principle of equivalence associates supergravity…
The new quantum number \sigma is introduced. It is shown that the conservation of \sigma-number results in the conservation of difference between baryon and lepton numbers obtained earlier by Georgi and Glashow. The conservation of \sigma…
The minimal flipped $SU(5)$ unification with the right-handed neutrino Majorana mass scale generated as a two-loop effect is arguably one of the most constrained models of perturbative baryon and lepton number violation currently on the…
We show that most features of the mass and mixing pattern of the second and third SM fermion families can be accounted for without making use of flavour symmetries or other types of flavour dynamics. We discuss the implications for flavour…
Previous studies have shown how the three generations of the Standard Model fermions can arise from a single generation in more than four dimensions, and how off-diagonal neutral couplings arise for gauge-boson Kaluza-Klein recurrences.…
We discuss lepton flavour violating signals at the LHC in the framework of supersymmetric theories. We consider R-parity conserving as well as R-parity violating scenarios. In the case of R-parity conservation we show that in decays of…
Can the Large Hadron Collider explain the masses and mixings of the known fermions? A promising possibility is that these masses and mixings are determined by flavor symmetries that also govern new particles that will appear at the LHC. We…
We have investigated a flavour model [1] which inspired by small squared-mass difference measured in solar neutrino oscillation experiments and observability in neutrinoless double beta decay experiments. In our model, the $1^{\rm st.}$ and…
We propose a new possibility to realize simultaneously the sufficient proton stability and the interesting structure of neutrino mass matrix in superstring inspired $E_6$ models. In this model the leptons and Higgs fields are assigned to a…
A four dimensional Superstring is constructed starting from a twenty six dimensional bosonic string. Fermions are introduced by noting the Manselstam's proof of equivalence of two fermions to one boson in 1+1 dimensions. The action of the…
$U(1)_X$SSM is the extension of the minimal supersymmetric standard model(MSSM) and its local gauge group is $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. To obtain this model, three singlet new Higgs superfields and right-handed…
The family symmetry $SU(3)\otimes U(1)$ is proposed to solve flavor problems about fermion masses and flavor mixings. It's breaking is implemented by some flavon fields at the high-energy scale. In addition a discrete group $Z_{2}$ is…
Baryon number ($B$) conservation underlies the apparent stability of ordinary matter by forbidding the decay of nucleons, while lepton number ($L$) conservation plays a central role in the structure of lepton interactions and the possible…