Sterile neutrinos

Abstract

Neutrino masses are usually described by adding to the Standard Model some SU(2)-singlet fermions that have the Yukawa couplings, as well as some Majorana mass terms. The number of such fields and the scales of their Majorana masses are not known. Several independent observations point to the possibility that some of these singlets may have masses well below the electroweak scale. A sterile neutrino with mass of a few keV can account for cosmological dark matter. The same particle would be emitted anisotropically from a cooling neutron star born in a supernova explosion. This anisotropy can be large enough to explain the observed velocities of pulsars. A lighter sterile neutrino, with mass of the order of eV, is implied by the LSND results; it can have profound implications for cosmology. We review the physics of sterile neutrinos and the roles they may play in astrophysics and cosmology.

11 pages, 1 figure; invited talk at the "12th Mexican School on particles and fields" and the "6th Latin American Symposium on high energy physics" (VI-Silafae/XII-MSPF)

Cited by in corpus (13)

• First results from DAMA/LIBRA and the combined results with DAMA/NaI
• The DAMA/LIBRA apparatus
• A lower bound on the mass of Dark Matter particles
• Constraints on dark matter particles from theory, galaxy observations and N-body simulations
• Clustering properties of a sterile neutrino dark matter candidate
• Signatures of heavy sterile neutrinos at long baseline experiments
• The dark matter transfer function: free streaming, particle statistics and memory of gravitational clustering
• Free streaming in mixed dark matter
• Production of a sterile species via active-sterile mixing: an exactly solvable model
• Consequences of a Pati-Salam unification of the electroweak-scale active ${\nu }_R$ model
• Unsterile-Active Neutrino Mixing: Consequences on Radiative Decay and Bounds from the X-ray Background
• Low Scale Leptogenesis from Non-Leptonic CP-Phases
• Production of a sterile species: quantum kinetics