Salah Nasri

A Model for neutrino masses and dark matter

Department of PhysicsSyracuse UniversitySyracuse, NY 13244-1130, USA(Dated: February 1, 2008)We propose a model for neutrino masses that simultaneously results in a new dark matter can-didate, the right-handed neutrino. We derive the dark matter abundance in this model, show howthe hierarchy of neutrino masses is obtained, and verify that the model is compatible with existingexperimental results. The model provides an economical method of unifying two seemingly separatepuzzles in contemporary particle physics and cosmology.

Radion stabilization in compact hyperbolic extra dimensions

We consider radion stabilization in hyperbolic brane-world scenarios. We demonstrate that in the context of Einstein gravity, matter fields which stabilize the extra dimensions must violate the null energy condition. This result is shown to hold even allowing for Friedmann-Robertson-Walker-like expansion on the brane. In particular, we explicitly demonstrate how one putative source of stabilizing matter fails to work, and how others violate the above condition. We speculate on a number of ways in which we may bypass this result, including the effect of Casimir energy in these spaces. A brief discussion of supersymmetry in these backgrounds is also given.

Three-loop model of neutrino mass with dark matter

Laboratoire de Physique Theorique, ES-SENIA University, DZ-31000 Oran, Algeria(Received 27 April 2014; published 22 July 2014)We propose a model in which the origin of neutrino mass is dependent on the existence of dark matter.Neutrinos acquire mass at the three-loop level and the dark matter is the neutral component of a fermiontriplet. We show that experimental constraints are satisfied and that the dark matter can be tested in futuredirect-detection experiments. Furthermore, the model predicts a charged scalar that can be within reach ofcollider experiments like the LHC.

A Model of Radiative Neutrino Mass: with or without Dark Matter

A bstractWe present a three-loop model of neutrino mass whose most-general Lagrangian possesses a softly-broken accidental Z2 symmetry. In the limit that a single parameter vanishes, λ →0, the Z2 symmetry becomes exact and the model contains a stable dark-matter candidate. However, even for finite λ ≪1, long-lived dark matter is possible, giving a unified solution to the neutrino mass and dark matter problems that does not invoke a new symmetry. Taken purely as a neutrino mass model, the new physics can be at the TeV scale. When dark matter is incorporated, however, only a singlet scalar can remain this light, though the dark matter can be tested in direct-detection experiments.

A class of three-loop models with neutrino mass and dark matter

Abstract We study a class of three-loop models for neutrino mass in which dark matter plays a key role in enabling the mass diagram. The simplest models in this class have Majorana dark matter and include the proposal of Krauss, Nasri and Trodden; we identify the remaining related models, including the viable colored variants. The next-to-simplest models use either more multiplets and/or a slight modification of the loop-diagram, and predict inert N-tuplet scalar dark matter.

Light dark matter, light Higgs boson, and the electroweak phase transition

We propose a minimal extension of the Standard Model by two real singlet fields that could provide a good candidate for light Dark Matter, and give a strong first order electroweak phase transition. As a result, there are two CP even scalars; one is lighter than \sim 70 GeV, and the other one with mass in the range of 280-400 GeV; and consistent with electroweak precision tests. We show that the light scalar mass can be as small as 25 GeV while still being consistent with the LEP data. The predicted dark matter scattering cross section is large enough to accommodate CoGeNT and can be probed by future XENON experiment. We also show that for dark matter mass around 2 GeV, the branching fraction of the process (B^+\rightarrowK^++2(DM)) can be accessible in SuperB factories.

Radiative neutrino mass model at the

We study the phenomenology of a Standard Model (SM) extension with two charged singlet scalars and three right handed (RH) neutrinos at an electron-positron collider. In this model, the neutrino mass is generated radiatively at three-loop, the lightest RH neutrino is a good dark matter candidate; and the electroweak phase transition strongly first order as required for baryogenesis. We focus on the process

e^-e^+

e^{+}+e^{-}\rightarrow e^{-}\mu^{+}+E_{miss}

linear collider

, where the model contains new lepton flavor violating interactions that contribute to the missing energy. We investigate the feasibility of detecting this process at future

A radiative model for the weak scale and neutrino mass via dark matter

e^{-}e^{+}