Amine Ahriche

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.

What is the Criterion for a Strong First Order Electroweak Phase Transition in Singlet Models

It is widely believed that the existence of singlet scalars in some standard model extensions can easily make the electroweak phase transition strongly first order, which is needed for the electroweak baryogenesis scenario. In this paper, we will examine the strength of the electroweak phase transition in the simplest extension of the standard model with a real singlet using the sphaleron energy at the critical temperature. We find that the phase transition is stronger by adding a singlet; and also that the criterion for a strong phase transition Omega(T-c)/T-c greater than or similar to 1, where Omega=(upsilon(2)+(x-x(0))(2))(1/2) and x (x(0)) is the singlet vev in the broken (symmetric) phase, is not valid for models containing singlets, even though often used in the literature. The usual condition upsilon(c)/T-c greater than or similar to 1 is more meaningful, and it is satisfied for a large part of the parameter space for physically allowed Higgs masses.

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.

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^{+}

The scale-invariant scotogenic model

linear colliders at different center of mass energies:

A critical analysis of one-loop neutrino mass models with minimal dark matter

E_{CM}