Aaron Quiskamp

Jan 16, 2024 | link.aps.org | Aaron Quiskamp |Ben McAllister |John Street |Paul Altin

We report the results of Phase 1b of the ORGAN experiment, a microwave cavity haloscope searching for dark matter axions in the 107.42–111.93  μeV mass range. The search excludes axions with two-photon coupling gaγγ≥4×10−12  GeV−1 with 95% confidence interval, setting the best upper bound to date and with the required sensitivity to exclude the axionlike particle cogenesis model for dark matter in this range.

Jan 16, 2024 | link.aps.org | Ben McAllister |John R St |Aaron Quiskamp |QDM Lab

Axions are a compelling dark matter candidate, and one of the primary techniques employed to search for them is the axion haloscope, in which a resonant cavity is deployed inside a strong magnetic field so that some of the surrounding axions may convert into photons via the inverse Primakoff effect and become trapped inside the resonator. Resonant cavity design is critical to the sensitivity of a haloscope, and several geometries have been utilized and proposed.

Jun 6, 2023 | onlinelibrary.wiley.com | Ben McAllister |Paul Altin |Supercomputing Swinburne |Aaron Quiskamp

The typical axion–photon coupling is governed by the Lagrangian term L ⊃ − 1 4 g a γ γ a ( t ) F μ ν F ∼ μ ν $$\begin{equation} \mathcal {L} \supset -\frac{1}{4}g_{a\gamma \gamma }\, a(t) \, F^{\mu \nu } \widetilde{F}_{ \mu \nu }\, \end{equation}$$ (2)where F μ ν $F^{\mu \nu }$ and F ∼ μ ν $\widetilde{F}^{\mu \nu }$ are the electromagnetic field strength and its dual, and a ( t ) $a(t)$ is the oscillating axion field.