Resurrecting low-mass axion dark matter via a dynamical QCD scale
Lucien Heurtier, Fei Huang, Tim M. P. Tait
Abstract
A bstract In the framework where the strong coupling is dynamical, the QCD sector may confine at a much higher temperature than it would in the Standard Model, and the temperature-dependent mass of the QCD axion evolves in a non-trivial way. We find that, depending on the evolution of Λ QCD , the axion field may undergo multiple distinct phases of damping and oscillation leading generically to a suppression of its relic abundance. Such a suppression could therefore open up a wide range of parameter space, resurrecting in particular axion dark-matter models with a large Peccei-Quinn scale f a ≫ 10 12 GeV, i.e., with a lighter mass than the standard QCD axion.
Topics & Concepts
AxionPhysicsQuantum chromodynamicsParticle physicsDark matterCoupling (piping)Standard Model (mathematical formulation)Strong CP problemGauge (firearms)Mechanical engineeringEngineeringArchaeologyHistoryDark Matter and Cosmic PhenomenaCosmology and Gravitation TheoriesParticle physics theoretical and experimental studies