The international research community has united in the development of the DALI (Dark-photons & Axion-Like particle Interferometer) experiment, a telescope with astro-particles for dark matter, the scientific goal of which is to search for axions and paraphotons in the range from 6 to 60 GHz. A proof-of-concept prototype is currently in the design and manufacturing phase.
The discovery of the axion will be a key episode in the history of physics. This hypothetical particle could solve two fundamental problems at the same time: the problem of charge and parity in the strong interaction and the mystery of dark matter. Despite the high scientific interest in its search, the search at high radio frequencies above 6 GHz has been almost abandoned due to the lack of high-sensitivity technology and its possible cost.
Predicted by 1970s theory, an axion is a hypothetical low-mass particle that interacts weakly with standard particles such as nucleons and electrons, as well as photons. These proposed interactions are being studied to try and detect the axion using various types of instruments. One of the promising methods is to study the interaction of axions with standard photons.
Axions mix with photons under the influence of a strong external magnetic field, such as those created by superconducting magnets in particle detectors or used for medical diagnostics using magnetic resonance, and create a weak radio or microwave signal.
The first axion detectors, made in the 80s and 90s, used a resonant cavity that inside the supermagnet amplified the weak microwave signal predicted by the axion in an attempt to bring it up to the power range found by scientific instruments. Unfortunately, the size of the resonator is inversely proportional to the scanning frequency, and for the axion, the resonators were too small to be made for frequencies above 6 GHz.
For this reason, the new experiment brings together the most promising high-frequency scanning techniques and incorporates them into practical development, to which the capabilities of astro-particle detectors for axion dark matter are also added. Thus, DALI includes a powerful superconducting magnet, an axion detector with a new resonator to detect a weak signal caused by axions, and an altazimuth mount to scan objects and regions in the sky in search of dark matter.
Thus, DALI could help detect the axion, a pseudoscalar particle similar in nature to the Higgs boson discovered in 2012 at CERN, and a promising dark matter candidate. Dark matter is a fundamental constituent of the Universe, which interacts very weakly with ordinary matter, therefore it is very difficult to detect it directly, but the discovery of which would allow us to explain the rotation curves of spiral galaxies and why the formation of structure in the Universe has evolved the same way as before, among other riddles.