The role of sterile neutrinos in cosmology and astrophysics

We present a comprehensive overview of an extension of the Standard Model that contains three right-handed (sterile) neutrinos with masses below the electroweak scale [the Neutrino Minimal Standard Model (vMSM)]. We consider the history of the Universe from the inflationary era through today and demonstrate that most of the observed phenomena beyond the Standard Model can be explained within the framework of this model. We review the mechanism of baryon asymmetry of the Universe in the vMSM and discuss a dark matter candidate that can be warm or cold and that satisfies all existing constraints. From the viewpoint of particle physics, the model provides an explanation for neutrino flavor oscillations. Verification of the vMSM is possible with existing experimental techniques. Copyright © 2009 by Annual Reviews. All rights reserved.

The nuMSM, inflation, and dark matter

Igor Tkachev

We show how to enlarge the νMSM (the minimal extension of the Standard Model by three right-handed neutrinos) to incorporate inflation and provide a common source for electroweak symmetry breaking and for right-handed neutrino masses. In addition to inflation, the resulting theory can explain simultaneously dark matter and the baryon asymmetry of the Universe; it is consistent with experiments on neutrino oscillations and with all astrophysical and cosmological constraints on sterile neutrino as a dark matter candidate. The mass of inflaton can be much smaller than the electroweak scale. © 2006 Elsevier B.V. All rights reserved.

2006

The nuMSM, dark matter and baryon asymmetry of the universe

We show that the extension of the standard model by three right-handed neutrinos with masses smaller than the electroweak scale (the νMSM) can explain simultaneously dark matter and baryon asymmetry of the universe and be consistent with the experiments on neutrino oscillations. Several constraints on the parameters of the νMSM are derived. © 2005 Elsevier B.V. All rights reserved.

2005

Dark matter, baryogenesis and neutrino oscillations from right-handed neutrinos

Laurent Canetti, Marco Drewes, Tibor Frossard

We show that, leaving aside accelerated cosmic expansion, all experimental data in high energy physics that are commonly agreed to require physics beyond the Standard Model can be explained when completing the model by three right-handed neutrinos that can be searched for using present-day experimental techniques. The model that realizes this scenario is known as the Neutrino Minimal Standard Model (nu MSM). In this article we give a comprehensive summary of all known constraints in the nu MSM, along with a pedagogical introduction to the model. We present the first complete quantitative study of the parameter space of the model where no physics beyond the nu MSM is needed to simultaneously explain neutrino oscillations, dark matter, and the baryon asymmetry of the Universe. The key new point of our analysis is leptogenesis after sphaleron freeze-out, which leads to resonant dark matter production, thus evading the constraints on sterile neutrino dark matter from structure formation and x-ray searches. This requires one to track the time evolution of left-and right-handed neutrino abundances from hot big bang initial conditions down to temperatures below the QCD scale. We find that the interplay of resonant amplifications, CP-violating flavor oscillations, scatterings, and decays leads to a number of previously unknown constraints on the sterile neutrino properties. We furthermore reanalyze bounds from past collider experiments and big bang nucleosynthesis in the face of recent evidence for a nonzero neutrino mixing angle theta(13). We combine all our results with existing constraints on dark matter properties from astrophysics and cosmology. Our results provide a guideline for future experimental searches for sterile neutrinos. A summary of the constraints on sterile neutrino masses and mixings has appeared in Canetti et al. [Phys. Rev. Lett. 110, 061801 (2013)]. In this article we provide all details of our calculations and give constraints on other model parameters.

Amer Physical Soc2013

Dark matter, baryogenesis and neutrino oscillations from right-handed neutrinos

Laurent Canetti, Marco Drewes, Tibor Frossard

Amer Physical Soc2013