Radiation back-reaction during dark-matter freeze-out via metastable bound states
arXiv:2402.13069 · doi:10.1088/1475-7516/2024/06/027
Abstract
The formation and decay of metastable bound states can deplete significantly the density of multi-TeV thermal-relic dark matter. The effect depends on the interplay of bound-state formation, ionisation, transition and decay processes. Existing calculations take into account bound-state ionisation and excitations due to the radiation of the thermal bath. However, the dynamics of Hydrogen recombination suggests that the resonant radiation produced in bound-state formation or de-excitations may backreact, ionising or exciting the bound states thus impeding recombination. In this paper we examine this effect in the context of dark-matter freeze-out. To this end, we employ the generalised Saha equilibrium equation for metastable bound states, and discuss its salient features. We show that, in sharp contrast to Hydrogen recombination, the radiation produced during dark matter freeze-out is more likely to thermalise or redshift, rather than ionise or excite the metastable bound states. This holds not only for the low-energy (resonant) radiation produced in bound-state formation and transition processes, but also for the high-energy radiation produced in dark-matter annihilations and bound-state decays. While our computations are carried out in a minimal dark model, our conclusions only strengthen in more complex models.
arXiv comment30 pages, 8 figures, minor corrections, published version
References in corpus (36)
- Secluded U(1) below the weak scale
- How exactly did the Universe become neutral?
- Sommerfeld factor for arbitrary partial wave processes
- Relativistic corrections to the Sunyaev-Zel'dovich effect
- WIMPonium and Boost Factors for Indirect Dark Matter Detection
- Bound-state formation for thermal relic dark matter and unitarity
- Dark-matter bound states from Feynman diagrams
- Gluino Coannihilation Revisited
- Radiative bound-state-formation cross-sections for dark matter interacting via a Yukawa potential
- Homeopathic Dark Matter, or how diluted heavy substances produce high energy cosmic rays
- Effects of Bound States on Dark Matter Annihilation
- Asymmetric thermal-relic dark matter: Sommerfeld-enhanced freeze-out, annihilation signals and unitarity bounds
- Capture and Decay of Electroweak WIMPonium
- Asymmetric dark matter: residual annihilations and self-interactions
- Radiative bound-state formation in unbroken perturbative non-Abelian theories and implications for dark matter
- Rapid thermal co-annihilation through bound states in QCD
- Thermal dark matter co-annihilating with a strongly interacting scalar
- Strong CMB Constraint On P-Wave Annihilating Dark Matter
- Non-Abelian Electric Field Correlator at NLO for Dark Matter Relic Abundance and Quarkonium Transport
- Dark Matter Sommerfeld-enhanced annihilation and Bound-state decay at finite temperature
- Re-derived overclosure bound for the inert doublet model
- Coloured coannihilations: Dark matter phenomenology meets non-relativistic EFTs
- Dark Matter bound-state formation at higher order: a non-equilibrium quantum field theory approach
- Higgs-mediated bound states in dark-matter models
- Rapid bound-state formation of Dark Matter in the Early Universe
- Scalar dark matter coannihilating with a coloured fermion
- Dark Matter Bound State Formation in Fermionic DM model with Light Dark Photon and Dark Higgs Boson
- Dark matter bound states via emission of scalar mediators
- Dark matter bound state formation via emission of a charged scalar
- Radiative transfer effects in primordial hydrogen recombination
- Excited bound states and their role in dark matter production
- Indirect searches for dark matter bound state formation and level transitions
- Saha equilibrium for metastable bound states and dark matter freeze-out
- Bound states of WIMP dark matter in Higgs-portal models. Part I. Cross-sections and transition rates
- Bound states of WIMP dark matter in Higgs-portal models. Part II. Thermal decoupling
- Dynamics of the Primordial Hydrogen and Helium (HeI) Recombination in the Universe