Sub-GeV dark matter that interacts hadronically is ruled out for nucleon scattering cross sections above 10^{-36} cm² across the keV to 100 MeV mass range by combined cosmological and particle-decay constraints.
A Lower Bound on the Mass of Cold Thermal Dark Matter from Planck
6 Pith papers cite this work. Polarity classification is still indexing.
abstract
We show that the new measurement of the effective number of neutrinos Neff by the Planck satellite can be used to set a robust lower bound on the mass of cold thermal dark matter of O(MeV). Our limit applies if the dark matter remains in thermal equilibrium by coupling to electrons and photons or through interactions with neutrinos, and applies regardless of whether the dark matter annihilation cross-section is s-wave or p-wave. To illustrate our bounds we apply them to a model of a supersymmetric neutralino annihilating to neutrinos, via a light mixed left-right handed sneutrino mediator. While this scenario was not constrained by previous data, the Planck limits on Neff allow us to set a lower bound on the neutralino dark matter mass of 3.5 MeV.
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Conventional BBN fitting for negative Delta N_eff is unphysical; a consistent treatment via entropy dilution after neutrino decoupling yields significantly different bounds.
Freeze-in at low reheating temperatures allows MeV-scale dark matter in vector portal models to be probed by future direct detection experiments in nuclear recoils for 50-500 MeV masses and via enhanced solar neutrino coherent scattering.
The thesis presents a new 3-to-2 freezeout mechanism, bound-state effects on searches, a new axion interferometric search, reionization assessments, 21-cm constraints, and the DarkHistory code for ionization and thermal histories.
Inelastic self-interacting dark matter with small mass splitting produces a cutoff in the matter power spectrum at k > 1 h Mpc^{-1} whose location depends on cross-section normalization, velocity dependence, dark matter mass and mass splitting, yielding non-monotonic exclusion regions from Lyman-α森林
Double beta decay experiments can constrain couplings of sub-MeV Majoron-like scalars to neutrinos at |a_ν| ≈ 2×10^{-6} through on- and off-shell production effects on the electron spectrum.
citing papers explorer
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Irreducible Constraints on Hadronically Interacting Sub-GeV Dark Matter
Sub-GeV dark matter that interacts hadronically is ruled out for nucleon scattering cross sections above 10^{-36} cm² across the keV to 100 MeV mass range by combined cosmological and particle-decay constraints.
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Consistent $N_{\rm eff}$ fitting in big bang nucleosynthesis analysis
Conventional BBN fitting for negative Delta N_eff is unphysical; a consistent treatment via entropy dilution after neutrino decoupling yields significantly different bounds.
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New benchmarks for direct detection of freeze-in dark matter in vector portal models
Freeze-in at low reheating temperatures allows MeV-scale dark matter in vector portal models to be probed by future direct detection experiments in nuclear recoils for 50-500 MeV masses and via enhanced solar neutrino coherent scattering.
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Dark Matter Energy Deposition and Production from the Table-Top to the Cosmos
The thesis presents a new 3-to-2 freezeout mechanism, bound-state effects on searches, a new axion interferometric search, reionization assessments, 21-cm constraints, and the DarkHistory code for ionization and thermal histories.
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Cosmology of Inelastic Self-Interacting Dark Matter: Linear Evolution and Observational Constraints
Inelastic self-interacting dark matter with small mass splitting produces a cutoff in the matter power spectrum at k > 1 h Mpc^{-1} whose location depends on cross-section normalization, velocity dependence, dark matter mass and mass splitting, yielding non-monotonic exclusion regions from Lyman-α森林
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Probing Dark Sector Particles Coupling to Neutrinos with Double Beta Decay
Double beta decay experiments can constrain couplings of sub-MeV Majoron-like scalars to neutrinos at |a_ν| ≈ 2×10^{-6} through on- and off-shell production effects on the electron spectrum.