Strong CP problem and axion dark matter with small instantons
Ryuichiro Kitano, Wen Yin
Abstract
A bstract The axion mass receives a large correction from small instantons if the QCD gets strongly coupled at high energies. We discuss the size of the new CP violating phases caused by the fact that the small instantons are sensitive to the UV physics. We also discuss the effects of the mass correction on the axion abundance of the Universe. Taking the small-instanton contributions into account, we propose a natural scenario of axion dark matter where the axion decay constant is as large as 10 15-16 GeV. The scenario works in the high-scale inflation models.
Topics & Concepts
AxionPhysicsInstantonParticle physicsDark matterInflation (cosmology)Quantum chromodynamicsStrong CP problemUniverseAstrophysicsTheoretical physicsDark Matter and Cosmic PhenomenaParticle physics theoretical and experimental studiesCosmology and Gravitation Theories