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 $2 \times 10^{ -11}\,\textrm{ GeV}^{ -1}$ for masses $m_a \leq 0.1\,\textrm{ meV}$. Two 120$\,$m long strings of superconducting dipole magnets have been set up, each providing a magnetic field-length product of $560\,\textrm{ T}\cdot\textrm{ m}$. 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 $6 \times 10^{ -10}\,\textrm{ GeV}^{ -1}$ for $m_a \leq 0.1\,\textrm{ meV}$. 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.
Categories: hep-ex