Is Self-Interacting Dark Matter Undergoing Dark Fusion?

Abstract

We suggest that two-to-two dark matter fusion may be the relaxation process that resolves the small-scale structure problems of the cold collisionless dark matter paradigm. In order for the fusion cross section to scale correctly across many decades of astrophysical masses from dwarf galaxies to galaxy clusters, we require the fractional binding energy released to be greater than v^n ~ [10^{-(2-3)}]^n, where n=1,2 depends on local dark sector chemistry. The size of the dark-sector interaction cross sections must be sigma ~ 0.1-1 barn, moderately larger than for Standard Model deuteron fusion, indicating a dark nuclear scale Lambda ~ O(100 MeV). Dark fusion firmly predicts constant sigma v below the characteristic velocities of galaxy clusters. Observations of the inner structure of galaxy groups with velocity dispersion of several hundred kilometer per second, of which a handful have been identified, could differentiate dark fusion from a dark photon model.

6 pages, 1 figure, comments welcome

References in corpus (17)

• Too big to fail? The puzzling darkness of massive Milky Way subhaloes
• The non-gravitational interactions of dark matter in colliding galaxy clusters
• Exciting Dark Matter and the INTEGRAL/SPI 511 keV signal
• Galaxy Groups within 3500 km s${}^{-1}$
• Resonant Dark Forces and Small Scale Structure
• Upper Bound on the Dark Matter Total Annihilation Cross Section
• Dark Nuclei I: Cosmology and Indirect Detection
• Higgs portal vector dark matter for $\mathrm{GeV}$ scale $\gamma$-ray excess from galactic center
• Hadronic forward scattering: Predictions for the Large Hadron Collider and cosmic rays
• BBN for the LHC: constraints on lifetimes of the Higgs portal scalars
• A weighty interpretation of the Galactic Centre excess
• Making Asymmetric Dark Matter Gold: Early Universe Synthesis of Nuggets
• Nuclear Structure of Bound States of Asymmetric Dark Matter
• Hidden Sector Hydrogen as Dark Matter: Small-scale Structure Formation Predictions and the Importance of Hyperfine Interactions
• Cosmological Simulations of Decaying Dark Matter: Implications for Small-scale Structure of Dark Matter Halos
• Dark Nuclei II: Nuclear Spectroscopy in Two-Colour QCD
• Cosmological Bounds on Non-Abelian Dark Forces

Cited by in corpus (19)

• Dark Quark Nuggets
• Constraining Dissipative Dark Matter Self-Interactions
• Velocity Dependence from Resonant Self-Interacting Dark Matter
• Maximally self-interacting dark matter: models and predictions
• Finite-size dark matter and its effect on small-scale structure
• Repurposing lattice QCD results for composite phenomenology
• Linear Sigma Dark Matter
• Core mass -- halo mass relation of bosonic and fermionic dark matter halos harbouring a supermassive black hole
• Electron-Positron Annihilation Freeze-Out in the Early Universe
• Neutrino As The Dark Force
• Cosmological Production of Dark Nuclei
• Escalating core formation with dark matter self-heating
• Core formation from self-heating dark matter
• A heuristic wave equation parameterizing BEC dark matter halos with a quantum core and an isothermal atmosphere
• Manifesting hidden dynamics of a sub-component dark matter
• Big Bang Nucleosynthesis and Neutrino Cosmology
• Late-Time Dark Matter Oscillations and the Core-Cusp Problem
• On Dark Matter Self-interaction via Single Neutrino Exchange Potential
• Constraints on energy scales from dark matter decay in a gauged $B-L$ model