Quadratic coupling of the axion to photons
Carl Beadle, Sebastian A. R. Ellis, Jérémie Quevillon, Pham Ngoc Hoa Vuong
Abstract
We show that the QCD axion couples to the electromagnetic kinetic term at one loop. The result is that if axions make up dark matter, they induce temporal variation of the fine structure constant <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi>α</a:mi></a:math>, which is severely constrained. We recast these constraints on the QCD axion parameter space. We also discuss how to generalize our finding to axionlike particles, and the resulting constraints. Published by the American Physical Society 2024
Topics & Concepts
AxionPhysicsParticle physicsQuantum chromodynamicsPhotonDark matterCoupling (piping)Coupling constantQuadratic equationParameter spaceTerm (time)Theoretical physicsQuantum mechanicsMathematicsGeometryMechanical engineeringEngineeringDark Matter and Cosmic PhenomenaCosmology and Gravitation TheoriesAtomic and Subatomic Physics Research