Exploring ALPs beyond the canonical

Axion-like particles (ALPs) are interesting dark matter candidates both from the theoretical as well as from the experimental perspective. Usually they are motivated as pseudo-Nambu-Goldstone bosons. In this case one of their most important features is that their coupling to other particles is suppr...

Full description

Saved in:
Bibliographic Details
Main Authors: Alonso Álvarez, Gonzalo (Author) , Jaeckel, Joerg (Author)
Format: Article (Journal) Chapter/Article
Language:English
Published: 20 Dec 2017
In: Arxiv

Online Access:Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1712.07500
Get full text
Author Notes:Gonzalo Alonso-Álvarez and Joerg Jaeckel
Description
Summary:Axion-like particles (ALPs) are interesting dark matter candidates both from the theoretical as well as from the experimental perspective. Usually they are motivated as pseudo-Nambu-Goldstone bosons. In this case one of their most important features is that their coupling to other particles is suppressed by a large scale, the vacuum expectation value of the field breaking the symmetry that gives rise to them. This naturally endows them with very weak interactions but also restricts the maximal field value and therefore the regions where sufficient dark matter is produced. In this paper we investigate deviations from this simplest setup, where the potential and interactions are as expected for a pseudo-Nambu-Goldstone boson, but the kinetic term has singularities. This leads to a significantly increased area in parameter space where such particles can be dark matter and can be probed by current and near future experiments. We discuss cosmological limits and in the course of this give a simple derivation of a formula for isocurvature fluctuations in models with general anharmonic potentials. As an application of this formula we give an update of the isocurvature constraints for QCD axion dark matter models, using the most recent results for the QCD topological susceptibility and the newest Planck data.
Item Description:Identifizierung der Ressource nach: Last revised 12 Jul 2018
Gesehen am 15.12.2020
Physical Description:Online Resource