Cold keV dark matter from decays and scatterings

Abstract

We explore ways of creating cold keV-scale dark matter by means of decays and scatterings. The main observation is that certain thermal freeze-in processes can lead to a cold dark matter distribution in regions with small available phase space. In this way the free-streaming length of keV particles can be suppressed without decoupling them too much from the Standard Model. In all cases, dark matter needs to be produced together with a heavy particle that carries away most of the initial momentum. For decays, this simply requires an off-diagonal DM coupling to two heavy particles; for scatterings, the coupling of soft DM to two heavy particles needs to be diagonal, in particular in spin space. Decays can thus lead to cold light DM of any spin, while scatterings only work for bosons with specific couplings. We explore a number of simple models and also comment on the connection to the tentative 3.5 keV line.

19 pages, 6 figures. published version

References in corpus (28)

• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• Sterile neutrinos, dark matter, and the pulsar velocities in models with a Higgs singlet
• Addressing the LHC flavour anomalies with horizontal gauge symmetries
• Dark-matter sterile neutrinos in models with a gauge singlet in the Higgs sector
• A lower bound on the mass of Dark Matter particles
• Redefining the Axion Window
• A second Higgs from the Higgs portal
• The Poker Face of the Majoron Dark Matter Model: LUX to keV Line
• Constraints from Ly-$\alpha$ forests on non-thermal dark matter including resonantly-produced sterile neutrinos
• Limits on a CP-violating scalar axion-nucleon interaction
• Vanishing Minors in the Neutrino Mass Matrix from Abelian Gauge Symmetries
• Decaying warm dark matter and neutrino masses
• Strongest model-independent bound on the lifetime of Dark Matter
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: Basic Concepts and Subtle Features
• The 7 keV axion dark matter and the X-ray line signal
• keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: The Most General Case
• FIMP realization of the scotogenic model
• Probing the scotogenic FIMP at the LHC
• X-ray photons from late-decaying majoron dark matter
• Relic Gravity Waves and 7 keV Dark Matter from a GeV scale inflaton
• Freeze-in Production of Sterile Neutrino Dark Matter in U(1)${}_{\mathrm{B}-\mathrm{L}}$ Model
• The cold dark matter content of Galactic dwarf spheroidals: no cores, no failures, no problem
• Thermalizing sterile neutrino dark matter
• Cosmological Implications of Light Sterile Neutrinos produced after the QCD Phase Transition
• Calculation of Momentum Distribution Function of a Non-thermal Fermionic Dark Matter
• Dark matter and observable Lepton Flavour Violation
• Neutrino Hierarchies from a Gauge Symmetry
• Warm Dark Matter in Two Higgs Doublet Models

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• Light Dark Matter: Models and Constraints
• How warm are non-thermal relics? Lyman-$\alpha$ bounds on out-of-equilibrium dark matter
• Visible Decay of Astrophysical Neutrinos at IceCube
• Lepton Flavor Violation with Displaced Vertices
• Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
• Baryogenesis and Dark Matter from Freeze-In
• Light Dark Matter: A Common Solution to the Lithium and $H_0$ Problems
• Dark Matter Annihilation Feedback in Cosmological Simulations II: The Influence on Gas and Halo Structure
• Phenomenology of Majorons