Cold Darkogenesis: Dark Matter and Baryon Asymmetry in Light of the PTA Signal

Abstract

We build upon the intriguing possibility that the recently reported nano-Hz gravitational wave signal by Pulsar Timing Array (PTA) experiments is sourced by a strong first-order phase transition from a nearly conformal dark sector. The phase transition has to be strongly supercooled to explain the signal amplitude, while the critical temperature has to be in the $\mathcal{O}$(GeV) range, as dictated by the peak frequency of the gravitational wave spectrum. However, the resulting strong supercooling exponentially dilutes away any pre-existing baryon asymmetry and dark matter, calling for a new paradigm of their productions. We then develop a mechanism of cold darkogenesis that generates a dark asymmetry during the phase transition from the textured dark $SU(2{)}_{\mathrm{D}}$ Higgs field. This dark asymmetry is transferred to the visible sector via neutron portal interactions, resulting in the observed baryon asymmetry. Furthermore, the mechanism naturally leads to the correct abundance of asymmetric dark matter, with self-interaction of the scale that is of the right order to solve the diversity problem in galactic rotation curves. Collider searches for mono-jets and dark matter direct detection experiments can dictate the viability of the model.

5 + 4 pages, 3 figures, matches published version

References in corpus (10)

• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
• The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals
• The NANOGrav 15-year Data Set: Search for Signals from New Physics
• Cosmological phase transitions: from perturbative particle physics to gravitational waves
• Darkogenesis
• Gravitational Waves and Dark Radiation from Dark Phase Transition: Connecting NANOGrav Pulsar Timing Data and Hubble Tension
• Baryogenesis from Strong CP Violation and the QCD Axion
• Pulsar Timing Arrays and Primordial Black Holes from a Supercooled Phase Transition
• Fitting a Self-Interacting Dark Matter Model to Data Ranging From Satellite Galaxies to Galaxy Clusters

Cited by in corpus (4)

• Sub-GeV dark matter and nano-Hertz gravitational waves from a classically conformal dark sector
• Multi-Messenger and Cosmological Constraints on Dark Matter through Two-Fluid Neutron Star Modeling
• Postsphaleron darkogenesis
• Neutron Portal and Dark Matter-Baryon Coincidence: from UV Completion to Phenomenology