Towards the first axion search results of the Any Light Particle Search II experiment

Any Light Particle Search II (ALPS II) is a dual optical cavity enhanced light-shining-through-a-wall (LSW) experiment at DESY in Hamburg looking for axions and axion-like particles with a target search sensitivity of $g_{a\gamma \gamma }$ down to $2\times {10}^{-11}{\text{GeV}}^{-1}$ for masses $m_a\le 0.1\text{meV}$. Two 120$$m long strings of superconducting dipole magnets have been set up, each providing a magnetic field-length product of $560\text{T}\cdot \text{m}$. A resonant optical cavity with a record-worthy storage time of as high as 7$$ms has been constructed to encompass one magnet string. During its initial data-taking phase ALPS II will be operated with a simplified optical configuration that facilitates the characterization of the experiment. The first ALPS II science run took place in May/June 2023 and achieved an estimated search sensitivity of $g_{a\gamma \gamma }$ of around $6\times {10}^{-10}{\text{GeV}}^{-1}$ for $m_a\le 0.1\text{meV}$. Data analysis and further data runs are under way. Final results on axion-photon coupling from the initial science runs of ALPS II are expected in early 2024.