Refined Bounds on MeV-scale Thermal Dark Sectors from BBN and the CMB
Reviewed by Pith T0 review T1 audit T2 compute T3 formal T4 kernel pith:FSLU6Y5Brecord.jsonopen to challenge →
read the original abstract
New light states thermally coupled to the Standard Model plasma alter the expansion history of the Universe and impact the synthesis of the primordial light elements. In this work, we carry out an exhaustive and precise analysis of the implications of MeV-scale BSM particles in Big Bang Nucleosynthesis (BBN) and for Cosmic Microwave Background (CMB) observations. We find that, BBN observations set a lower bound on the thermal dark matter mass of $m_\chi > 0.4\,\text{MeV}$ at $2\sigma$. This bound is independent of the spin and number of internal degrees of freedom of the particle, of the annihilation being s-wave or p-wave, and of the annihilation final state. Furthermore, we show that current BBN plus CMB observations constrain purely electrophilic and neutrinophilic BSM species to have a mass, $m_\chi > 3.7\,\text{MeV}$ at $2\sigma$. We explore the reach of future BBN measurements and show that upcoming CMB missions should improve the bounds on light BSM thermal states to $m_\chi > (10-15)\,\text{MeV}$. Finally, we demonstrate that very light BSM species thermally coupled to the SM plasma are highly disfavoured by current cosmological observations.
This paper has not been read by Pith yet.
Forward citations
Cited by 11 Pith papers
-
Probing Cosmic-Ray-Boosted and Supernova-Sourced Sub-GeV Dark Matter with Paleo-Detectors
Paleo-detectors can achieve high sensitivity to sub-GeV dark matter boosted by cosmic rays and supernovae, covering previously inaccessible parameter space with orders of magnitude better reach than current experiments.
-
Theory Calculations for LDMX and LOHENGRIN beyond Coherent Bethe-Heitler Scattering
Higher-order electromagnetic and hadronic contributions to dark photon bremsstrahlung have limited impact on signal and background predictions for LDMX and LOHENGRIN except for requiring an HCAL extension in LOHENGRIN...
-
CMB Limits on the Absorption of Light Vector and Axial-Vector Dark Matter
Planck CMB data set upper limits on vector and axial-vector dark matter-electron couplings for masses 100 eV to 100 keV via energy injection from inelastic scattering and hydrogen absorption.
-
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.
-
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.
-
Dark matter energy exchange in stars orbiting supermassive black holes
Orbit-averaged DM energy exchange for S4714 reaches stellar luminosity at σ_χp ~ 10^{-36} cm² (MeV-GeV) and σ_χe ~ 5×10^{-38} cm² (sub-MeV) for spiked DM profiles.
-
Boosted Dark Matter from Sagittarius A$^\star$
The nuclear star cluster around Sgr A* is the dominant source of gravitationally boosted dark matter in the Milky Way, with particles up to ~25,000 km/s that enhance sub-GeV detection prospects independently of the DM model.
-
Dark Matter Interpretation of the Super-Kamiokande Antineutrino Excess and Predictions for JUNO
Interprets Super-Kamiokande antineutrino excess as s-wave annihilating dark matter with mass in the tens of MeV, predicting signals for JUNO.
-
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 matt...
-
Joint probes of dark matter annihilation from neutrino detectors and CMB targets
Joint analysis of neutrino detectors and CMB observables can constrain dark matter annihilation into neutrinos for MeV-GeV masses.
-
Dark Matter Interpretation of the Super-Kamiokande Antineutrino Excess in $\mathrm{U}(1)_{L_\mu-L_\tau}$ model
A 22 MeV Dirac dark matter particle in a U(1)_{Lμ-Lτ} model annihilates to muon and tau neutrinos that oscillate to explain the SK excess while matching thermal relic abundance.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.