Relaxion fluctuations (self-stopping relaxion) and overview of relaxion stopping mechanisms
Journal of high energy physics 2005(5), 80 (2020). doi:10.1007/JHEP05(2020)080
Probing photophobic axion and relaxion dark matter
We investigate the interplay between early universe cosmology and dark matter direct detection, considering axion models with naturally suppressed couplings to photons. In the context of the cosmological relaxation of the electroweak scale, we focus on a scenario of relaxion dark matter, in which the relaxion field constitutes all the observed dark matter relic density and its allowed mass range is fixed to a few keV by construction. In particular, we show that a relaxion particle with mass mϕ=3.0 keV which couples to electrons with gϕ,e=6.8×10−14 is consistent with the XENON1T excess, while accounting for the observed dark matter and satisfying astro/cosmo probes. This scenario uses the el…
Super-Planckian axions from near-conformality
We present a novel framework for obtaining large hierarchies in axion decay constants as well as trans-Planckian field excursions, with no need for tuning or a large number of fields. We consider a model with two or more conformal field theories with a common cutoff, which are linked by a gauged diagonal symmetry. This construction is dual to the geometry of a warped space with two or more throats glued at a common brane. Besides allowing for calculability, the dual picture makes it possible to interpret the hierarchy of decay constants entirely in terms of the geometry. Our setup can be applied to any framework which requires large field excursions or multiple hierarchies of decay constant…