Related papers: Astrophobic Axions
Scenarios with axion-like particles of variable masses, from the milli-eV range to ultralight, can be generated in a natural way in the context of effective field theory models with anomalous $U(1)$ gauge symmetries. They include…
The CERN Axion Solar Telescope (CAST) experiment searches for solar axions by the "helioscope" method. First results imply an upper limit on the axion-photon coupling of g_a-gamma < 1.16 x 10^-10 GeV^-1 (95% CL) for m_a < 0.02 eV, in this…
Hidden photons and axion-like particles are candidates for cold dark matter if they were produced non-thermally in the early universe. We conducted a search for both of these bosons using 800 live-days of data from the XMASS detector with…
We propose a KSVZ-type axion framework in which vector-like quarks (VLQ) and colored scalars generate Dirac neutrino masses radiatively. The global Peccei-Quinn symmetry (under which the exotic fermions are charged) addresses the strong CP…
Axions and axion-like particles (ALPs) remain highly motivated extensions to the standard model due to their ability to address open questions such as the relic abundance of dark matter and the strong CP problem. Axions are also capable of…
We consider a dark sector model containing stable fermions charged under an unbroken $U(1)$ gauge interaction, with a massless dark photon as force carrier, and interacting with ordinary matter via scalar messengers. We study its early…
Axino as the superpartner of axion that solves the strong CP problem can be a good candidate of dark matter. Inspired by the 3.5 keV X-ray line signal found to be originated from galaxy clusters and Andromeda galaxy, we study axino models…
The axion solution of the strong CP problem provides a number of possible windows to physics beyond the standard model, notably in the form of searches for solar axions and for galactic axion dark matter, but in a broader context also…
Axions are a theoretically promising dark matter (DM) candidate. In the presence of radiation from bright astrophysical sources at radio frequencies, nonrelativistic DM axions can undergo stimulated decay to two nearly back-to-back photons,…
Axion-like particles are promising candidates to make up the dark matter of the universe, but it is challenging to design experiments that can detect them over their entire allowed mass range. Dark matter in general, and in particular…
The dark sector offers a compelling theoretical framework for addressing the nature of dark matter while potentially solving other fundamental problems in physics. This review focuses on light dark flavored sector models, which are those…
Axions arise in many theoretical extensions of the Standard Model of particle physics, in particular the "string axiverse". If the axion masses, $m_a$, and (effective) decay constants, $f_a$, lie in specific ranges, then axions contribute…
Recent measurements by several experimental collaborations have reported deviations from Standard Model (SM) predictions in diphoton final states, potentially hinting at the existence of intermediate scalar resonances above the electroweak…
We consider a 5D extension of the DFSZ axion model that addresses both the axion quality and fermion mass hierarchy problems, and predicts flavour-dependent, off-diagonal axion-fermion couplings. The axion is part of a 5D complex scalar…
The domain wall problem of the Peccei-Quinn mechanism can be solved if the Peccei-Quinn symmetry is explicitly broken by a small amount. Domain walls decay into axions, which may account for dark matter of the universe. This scheme is…
We study axion dark matter production from a misalignment mechanism in scenarios featuring a general nonstandard cosmology. Before the onset of Big Bang nucleosynthesis, the energy density of the universe is dominated by a particle field…
There are several issues to do with dwarf galaxy predictions in the standard $\Lambda$CDM cosmology that have suscitated much recent debate about the possible modification of the nature of dark matter as providing a solution. We explore a…
We present a mechanism wherein the QCD axion coupling to nucleons, photons, or electrons, can be enhanced selectively without increasing the axion mass. We focus in particular on the axion-nucleon couplings, that are generally considered to…
Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting…
Nucleophobic axion models, wherein axion couplings to both protons and neutrons are simultaneously suppressed, can relax the stringent constraints from SN 1987A. However, it remains uncertain whether these models maintain their nucleophobic…