2020/12/17 by David McKeen, Maxim Pospelov, Nirmal Raj · 35 citations
Physics and Astronomy · #Astrophysics #Baryon #Baryonic dark matter #Big Bang nucleosynthesis #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark fluid #Dark matter #Nucleosynthesis #Particle physics #Physics #Pulsars and Gravitational Waves Research #Supernova #astro-ph.CO #astro-ph.HE #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.103.115002
published in Physical review. D/Physical review. D. 103(11) (American Physical Society) · 10 pages + refs revtex4, 4 figures
arxiv created 2020/12/17 · openalex publication_date 2021/06/02 · arxiv updated 2021/06/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We examine the cosmological and astrophysical signatures of a ``dark baryon,'' a neutral fermion that mixes with the neutron. As the mixing is through a higher-dimensional operator at the quark level, production of the dark baryon at high energies is enhanced so that its abundance in the early universe may be significant. Treating its initial abundance as a free parameter, we derive new, powerful limits on the properties of the dark baryon. Primordial nucleosynthesis and the cosmic microwave background provide strong constraints due to the interconversion of neutrons to dark baryons through their induced transition dipole, and due to late decays of the dark baryon. Additionally, neutrons in a neutron star could decay slowly to dark baryons, providing a novel source of heat that is constrained by measurements of pulsar temperatures. Taking all the constraints into account, we identify parameter space where the dark baryon can be a viable dark matter candidate and discuss promising avenues for probing it.