Related papers: Allowable Low-Energy E_6 Subgroups from Leptogenes…
We provide a minimal alternative gauged U(1)$_{\rm B-L}$ model in which three right-handed neutrinos with charges of (5,-4,-4) and only one B-L Higgs field with charge 1 are introduced. Consistent active neutrino masses and mixings can be…
It is shown that a supersymmetric SO(10) model extended with fermion singlets can accommodate the observed neutrino masses and mixings as well as generate the desired lepton asymmetry in concordance with the gravitino constraint. A…
The effective Lagrangian for the seesaw model is derived. Besides the usual dimension-5 operator responsible for light neutrino masses, a dimension-6 operator is included which, for three or less heavy neutrino generations, provides a…
We present a supersymmetric model of leptogenesis in which the right-handed neutrinos have weak scale masses and O(10-2-10-3) yukawa couplings. The model employs an R-symmetry at the weak scale that forces neutrino masses to be proportional…
The $SU(3)_c\otimes SU(3)_L\otimes U(1)_N$ model of Pisano and Pleitez extends the Standard Model in a particularly nice way, so that for example the anomalies cancel only when the number of generations is divisible by three. The original…
We study the most promising signals for supersymmetry at LEPII in the context of two well motivated supergravity models: (i) the minimal $SU(5)$ supergravity model including the stringent constraints from proton stability and a not too…
We investigate the possibility that quarks and leptons are unified at a low energy scale much smaller than the grand unified scale. A simple theory for quark-lepton unification based on the gauge group SU(4)_C X SU(2)_L X U(1)_R is…
We extend the results of a previous analysis of ours showing that, when both heavy and light flavour effects are taken into account, successful minimal (type I + thermal) leptogenesis with SO(10)-inspired relations is possible. Barring fine…
Working within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking (SUGRA), we map out regions of parameter space explorable by experiments at LEP2, for center of mass…
We consider an extended supersymmetric SO(10) seesaw model with only doublet Higgs scalars, in which neutrino masses are suppressed by the scale of D-parity violation. Leptogenesis can occur at the TeV scale through the decay of a singlet…
We suppose that the lightest supersymmetric particle (LSP) in the minimal supersymmetric standard model (MSSM) is the dark matter. The bino-like LSP can decay through the SO(10) gauge interactions, if one right-handed (RH) neutrino…
Assuming that the Standard Model arises from the $E_8\times E_8$ Heterotic Superstring, we try to solve the discrepancy between the unification scale predicted by this theory ($\approx g_{GUT}\times 5.27\cdot 10^{17}$ GeV) and the value…
We show that in supersymmetric models with gauged B-L symmetry, there is a new source for cosmological lepton asymmetry. The Higgs bosons responsible for B-L gauge symmetry breaking decay dominantly into right-handed sneutrinos \tilde{N}…
In the minimal left-right symmetric theory, the dark matter candidate is usually ascribed to the lightest right-handed neutrino. Here we present an alternative decaying dark matter candidate in this model in terms of the lightest neutral…
Low-scale leptogenesis is an attractive explanation for the observed baryon asymmetry of our universe that can be tested at a variety of laboratory experiments. In these proceedings, we review some recent advances in this field. In…
We study thermal leptogenesis in a broad class of supersymmetric SO(10) models with a left-right symmetric seesaw mechanism, taking into account flavour effects and the contribution of the next-to-lightest right-handed neutrino…
Extending the Minimal Supersymmetric Standard Model with three right-handed neutrino superfields is one of the best motivated scenarios for physics beyond the Standard Model. However, very little is known from observations about the high…
Various hints on the neutrino masses namely, ({\em i}) the solar neutrino deficit ({\em ii}) the atmospheric neutrino deficit ({\em iii}) the need for the dark matter and/or ({\em iv}) the non-zero neutrinoless double beta decay…
It is well-known that thermal leptogenesis through the decays of the lightest right-handed neutrinos encounters serious difficulties when SO(10)-inspired mass conditions are imposed on the Dirac neutrino mass matrix and light neutrino…
We embed the minimal left-right model SU(2)_L*SU(2)_R* U(1)_{B-L} into an SU(4)_W gauge group, and break the unified group via five-dimensional S^1/(Z_2*Z_2) orbifolding. Leptons are fitted into SU(4)_W multiplets and located on a symmetry…