A Search for Dark Matter utilizing Artificial Intelligence and a High-Frequency Cavity

Project by Mehmet Agit Akgümüs and Nabil Salama

Dark Matter is one of the most mysterious problems of modern physics and thousands of scientists are actively working on this issue. Our goal is, like many research groups around the world, to go on a search for Dark Matter and analyze the physical effects of cavity resonators, which are potentially capable of detecting it. Our research project is based on the results of theoretical physics, which predicts the existence of those particles. In addition, we will investigate the applicability of artificial intelligence to optimize the design and simulations. Already in 1933 Dark Matter was suspected for the first time with the observation of near galaxies. Meanwhile, its existence is supported by many cosmological observations and measurements. Many physical theories propose various, yet undiscovered, elementary particles as candidates for this unexplained matter. Two of the most promising candidates are the axion or the dark photon, which are also frequently reported in the scientific media. According to the Primakoff theory the axion interacts with a magnetic field and could transform into a photon, which then can be detected. The dark photon, on the other hand, does not have to be converted first. A converted or dark photon is amplified with a cavity resonator so that a measurement of its very low power is possible. Developing such a cavity resonator, which allows for storing electromagnetic waves at specific resonant frequencies, is one of the main aspects of our research project. A dark photon can be searched for using a resonating cavity also in the absence of an external magnetic field.

Realizing the experiment

The experiment also needs to be calibrated. For this purpose, an artificial signal is generated, which will be sent into the cavity and then the reflected and transmitted portion of the wave is analyzed. This allows the electromagnetic field in the resonator, the modes as well as the cavity behavior to be investigated. After all the preparations are completed, the measurements will be performed. For the axion search the calibrated RF cavity will be installed inside a high-field 14 Tesla magnet, provided by the Excellence Cluster “Quantum Universe”. We will do multiple measurements, each one of them could take up to a few weeks and will be conducted at a frequency range of around 4 GHz, with some variance induced through tuning methods. We expect to be able to detect signals above a minimal sensitivity of g_aγ > 3.5·10⁻¹¹ GeV⁻¹. To analyze the supposedly very weak signal at the order of 10^-21 watts during measurement, it needs to be amplified before it can be fed into an oscilloscope or spectrum analyzer. The signal will be averaged out over the duration of 1-2 weeks, such that the (amplified) noise cancels out.

Evaluation

After the measurements are done we will reach the most important part of the whole research project, the evaluation. Here we will find out if we detected a particle or could exclude that one exists in the particle mass range scanned by us, which would be a great scientific success either way since we would be the first to scan this area. In addition, we can test the applicability of artificial intelligence to simulate our cavity. In the framework of our project, a small cooperation with the Max Planck Institute in Munich could take place, to use their receiver chain for our experiment. Moreover, this research project itself is a collaboration of Professor Hillert’s and Professor Garutti’s research groups, which are also providing us with equipment and helpful suggestions.

Acknowledgment

Funded by the Federal Ministry of Education and Research (BMBF) and the Free and Hanseatic City of Hamburg under the Excellence Strategy of the Federal Government and the Federal States