Paul Altin

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.

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.