Conveners
Axion: Axion Model Building and Detection
- Chen Sun (Tel Aviv University)
Axion: Axion Detection and ALPs
- Christopher Verhaaren (Brigham Young University)
A heavy axion avoids the quality problem and has been shown to produce interesting experimental signatures. A mirror sector has been invoked to explain how such axions can occur, often with a large hierarchy between the visible and mirror Higgs masses. I discuss a novel realization of the Twin Higgs framework that produces a heavy axion without this large hierarchy, addressing both the strong...
The axion or axion like particle (ALP), as a leading dark matter candidate, is the target of many on-going and proposed experimental searches based on its coupling to photons. However, indirect searches for axions have not been as competitive as direct searches that can probe a large range of parameter space. In this talk, I will introduce the idea that axion stars will inevitably form in the...
Ultra-light axions with weak couplings to photons are motivated extensions of the Standard Model. We perform one of the most sensitive searches to-date for the existence of these particles with the NuSTAR telescope by searching for axion production in stars in the M82 starburst galaxy and the M87 central galaxy of the Virgo cluster. This involves a sum over the full stellar populations in...
In the presence of axion dark matter, electrons experience an "axion wind" spin torque and an "axioelectric" force, which give rise to magnetization and polarization currents in common ferrite materials. The radiation produced by these currents can be amplified in multilayer setups, which are potentially sensitive to the QCD axion without requiring a large external magnetic field.
We identify a new resonance, axion magnetic resonance (AMR), that can greatly enhance the conversion rate between axions and photons. A series of axion search experiments rely on converting them into photons inside a constant magnetic field background. A common bottleneck of such experiments is the conversion amplitude being suppressed by the axion mass when $m_a \gtrsim 10^{-4}~$eV. We...
I will discuss a recently proposed novel experimental setup for axion-like particle (ALP) searches. Nuclear reactors produce a copious number of photons, a fraction of which could convert into ALPs via the Primakoff process in the reactor core. The generated flux of ALPs leaves the nuclear power plant, and its passage through a region with a strong magnetic field results in efficient...
We derive new constraints on axion-like particles (ALPs) using precision $X$-ray polarization studies of magnetars. Specifically, we use the first detection of polarized $X$-rays from the magnetars 4U 0142+61 and 1RXS J170849.0-400910 by the Imaging $X$-ray Polarimetry Explorer (IXPE) to place bounds on the product of the ALP-photon and ALP-nucleon couplings, $g_{a\gamma}g_{aN}$, with...
