Thermal axion production in the primordial quark-gluon plasma

Abstract

We calculate the rate for thermal production of axions via scattering of quarks and gluons in the primordial quark-gluon plasma. To obtain a finite result in a gauge-invariant way that is consistent to leading order in the strong gauge coupling, we use systematic field theoretical methods such as hard thermal loop resummation and the Braaten-Yuan prescription. The thermally produced yield, the decoupling temperature, and the density parameter are computed for axions with a mass below 10 meV. In this regime, with a Peccei-Quinn scale above 6x10^8 GeV, the associated axion population can still be relativistic today and can coexist with the axion cold dark matter condensate.

5 pages, 4 figures; v2: typo in (15) corrected, one reference added; v3: minor changes, references added, matches published version

References in corpus (2)

• Isocurvature bounds on axions revisited
• Electroweak Contributions to Thermal Gravitino Production

Cited by in corpus (4)

• A Simple Motivated Completion of the Standard Model below the Planck Scale: Axions and Right-Handed Neutrinos
• Future cosmological sensitivity for hot dark matter axions
• Axions and saxions from the primordial supersymmetric plasma and extra radiation signatures
• Cosmological limits on axions and axion-like particles