Related papers: Universal 2-3 symmetry
We construct a simple model of fermion masses based on a spontaneously broken S3 X Z3 flavour group. At the leading order, in the neutrino sector S3 is broken down to a \nu_\mu-\nu_\tau parity subgroup that enforces a maximal atmospheric…
We study the implications of a large nu_mu - nu_tau mixing angle on flavour changing transitions of quarks and leptons in supersymmetric extensions of the standard model. Two patterns of supersymmetry breaking are considered, models with…
As neutrino experiments are starting to probe the detailed structure of the neutrino mass matrix, we present sumrules relating its matrix elements for a class of models with approximate $L_e-L_{\mu}-L_{\tau}$ symmetry and the observables in…
We investigate the potential (small) deviations from the unitarity of the mixing matrix that are expected to occur, because of mass splittings, in the Quantum Field Theory of non-degenerate coupled systems. We extend our previous analysis…
The recently announced Super-Kamiokande data on atmospheric neutrino oscillation seems to require a maximal mixing between the $\nu_{\mu}$ and $\nu_{\tau}$ within the conventional three neutrino picture. It is then tempting to suggest as…
We propose a new mechanism in which the generation of the supersymmetric $\mu $-term as well charged lepton masses is closely tied to R-parity violation involving heavy vector-like families . A realistic example based on $SU(3)_c\times…
The data on atmospheric neutrinos can be explained assuming the existence of oscillations between muon neutrinos and light sterile neutrinos with mixing close to maximal, and Delta_m^2 approximately equal to 3 E-3 (eV^2). This…
The $\mu\tau$-reflection symmetric neutrino mass matrix can accommodate all known neutrino mixing angles, with maximal atmospheric angle fixed, and predicts all the unknown CP phases of the lepton sector but is unable to predict the…
The $\mu$-$\tau$ reflection symmetry $(\nu_{e},\thinspace\nu_{\mu},\thinspace\nu_{\tau})\rightarrow(\overline{\nu}_{e},\thinspace\overline{\nu}_{\tau},\thinspace\overline{\nu}_{\mu})$ and the TM1 mixing (a PMNS matrix with the first column…
Models of neutrino masses are discussed capable of explaining in a natural way the maximal mixing between $\nu_{\mu}$ and $\nu_{\tau}$ observed by the Super-Kamiokande collaboration. For three generations of leptons two classes of such…
In the limit of an approximate $\mu-\tau$ symmetry in the neutrino mass matrix, we explore deviations to the Tri-Bi-Maximal mixing pattern in the neutrino sector. We consider two different ansatzes for the corrected pattern to predict the…
The atmospheric neutrino oscillations and the vacuum oscillation solution of the solar neutrino problem can be consistently described by a doubly or triply degenerate neutrino spectrum as long as the high level of degeneracy required is not…
We consider the Yukawa couplings for quarks and leptons in the context of Pati-Salam model using intersecting D-brane models where the Yukawa coupling matrices are rank one in a simple choice of family replication. The CKM mixings can be…
Assuming that the neutrino mass matrix is dominated by a term with the permutation symmetry $S_{\scriptscriptstyle 3}$ it is possible to explain neutrino data only if the masses are quasi-degenerate. A sub-dominant term with an approximate…
We diagonalize Majorana neutrino mass matrix with the help of PMNS matrix and obtain analytical relations between the mass matrix elements and mixing parameters, viz., three mixing angles- $\theta_{12}, \theta_{23}, \theta_{13}$ and Dirac…
We propose a renormalizable theory based on the $SU(3)_C\times SU(3)_L\times U(1)_X$ gauge symmetry, supplemented by the spontaneously broken $U(1)_{L_g}$ global lepton number symmetry and the $S_3 \times Z_2 $ discrete group, which…
We consider the flavor symmetry L_mu - L_tau for the neutrino mass matrix. The most general neutrino mass matrix conserving L_mu - L_tau predicts quasi-degenerate neutrino masses with one maximal and two zero mixing angles. The presence of…
I attempt to quantify how far from maximal one should expect the atmospheric mixing angle to be given a neutrino mass-matrix that leads, at zeroth order, to a nu_3 mass-eigenstate that is 0% nu_e, 50% nu_mu, and 50% nu_tau. This is done by…
Extrapolating the tau and b masses in the MSSM tends to give for their ratio at the GUT scale a number around 1.2, for most viable values \tan \beta, rather than the minimal SU(5) prediction of 1. We suggest that this may be due to large…
In drawing on an analogy with the flavor mixing observed in the quark sector we discuss a pattern of large flavor mixing angles in the lepton sector. Simple arguments based on a democratic symmetry and its violation in the lepton sector…