Related papers: Stellar cooling anomalies and variant axion models
We study a class of DFSZ-like models for the QCD axion that can address observed anomalies in stellar cooling. Stringent constraints from SN1987A and neutron stars are avoided by suppressed couplings to nucleons, while axion couplings to…
We study the axion cooling of neutron stars within the Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) model, which allows for tree level coupling of electrons to the axion {and locks the Peccei-Quinn charges of fermions via an angle parameter}.…
We present a QCD axion model where the couplings of the axion to nucleons, electrons, and muons are naturally suppressed because of the appropriate choice of the Peccei-Quinn charges of the Standard Model fermions. We reexamine…
Cooling simulations of neutron stars and their comparison with the data from thermally emitting x-ray sources put constraints on the properties of axions, and by extension of any light pseudoscalar dark matter particles, whose existence has…
Axion production from astrophysical bodies is a topic in continuous development, because of theoretical progress in the estimate of stellar emission rates and, especially, because of improved stellar observations. We carry out a…
We perform for the first time a dedicated analysis of cosmological constraints on DFSZ QCD axion models. Such constructions are especially interesting in light of the recent Xenon-1T excess and of hints from stellar cooling. In DFSZ models,…
The strongest upper bounds on the axion mass come from astrophysical observations like the neutrino burst duration of SN1987A, which depends on the axion couplings to nucleons, or the white-dwarf cooling rates and red-giant evolution, which…
We review the current status of the anomalies in stellar cooling and argue that, among the new physics candidates, an axion-like particle would represent the best option to account for the hinted additional cooling.
We analyse the cooling of white dwarfs in the globular cluster 47 Tucanae to look for evidence of axion emission affecting the rate of white dwarf cooling. If axions exist and couple to electrons, then axions could be produced at an…
Among many possibilities, solar axion has been proposed to explain the electronic recoil events excess observed by Xenon1T collaboration, although it has tension with astrophysical observations. The axion couplings, to photon $g_{a\gamma}$…
A particular class of variant axion models with two higgs doublets and a singlet is studied. In these models the axion couples either to the $u$-quark or $t$-quark or both, but not to $b$, $c$, $s$, or $d$. When the axion couples to only…
We propose a model for the QCD axion which is realized through a coupling of the Peccei-Quinn scalar field to magnetically charged fermions at high energies. We show that the axion of this model solves the strong CP problem and then…
We systematically calculate the axion-photon coupling for non-minimal DFSZ models. Thereby we can classify every calculated model and study the resulting distributions, relevant for axion experiments like haloscopes, helioscopes or…
It is known for some time that the cosmological bound on the invisible axion scale can be avoided by an early phase of strong QCD. While most approaches rely on theories where the strong coupling constant is determined through the…
The thermal evolution of a neutron star is studied by including the energy loss due to axion emission. Two axion models and three types of neutron-star matter equation of state are used with the effects of nucleon superfluidity properly…
We review and update the current status of the observed anomalies in stellar cooling and their interpretation in terms of axions and axion like particles.
Direct Chandra observations of a surface temperature of isolated neutron star in Cassiopeia A (Cas A NS) and its cooling scenario which has been recently simultaneously suggested by several scientific teams put stringent constraints on…
The observed anomalous steady decrease in surface temperature of the supernova remnant Cassiopeia A (Cas A), which was reported about ten years ago, has generated much debate. Several exotic cooling scenarios have been proposed using…
Several stellar systems (white dwarfs, red giants, horizontal branch stars and possibly the neutron star in the supernova remnant Cassiopeia A) show a mild preference for a non-standard cooling mechanism when compared with theoretical…
We present global fits of cosmologically stable axion-like particle and QCD axion models in the mass range 0.1 neV to 10 eV. We focus on the case where the Peccei-Quinn symmetry is broken before the end of inflation, such that the initial…