Axion-like Particle Searches (Project ALP)

• Applicants: Professor Dr. Achim Denig, since 2/2023; Professor Dr. Marc Vanderhaeghen
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458854507

Two-photon fusion processes hold the potential to provide a discovery mode for axions, axion-like particles (ALPs), and more generally dark-sector particles. Over the past few decades, a rich phenomenology has been explored in the search for axions and dark-sector particles, leading to bounds from astrophysics, cosmology, hadronic, and collider physics. The Project ALP aims to search for ALPs and dark-sector particles through experiments in the MeV - GeV hadronic mass regime at BESIII, MAMI, and MESA, and at high-energy collider experiments such as ATLAS. In the MESA energy range we will explore the signal for the production of the conjectured X17 particle through dilepton photoproduction on a nucleon, and thus shed an independent light on the anomalies seen in several nuclear decays. At the A2 experiment at MAMI the large eta-meson data sample will allow to study rare eta decays in search of new particles. The ALP searches at MAMI and MESA will be complemented at BESIII based on existing and upcoming data sets by using the ALP-strahlung process, and feasibility studies for dedicated X17 searches at BESIII will be worked out. Furthermore ALP searches at the LHC through the photon-photon scattering will allow to probe axion masses between few GeV to few 100 GeV.

• DFG Programme: Research Units
• Subproject of: FOR 5327: Photon-photon interactions in the Standard Model and beyond - exploiting the discovery potential from MESA to the LHC
• International Connection: Poland
• Co-Investigators: Dr. Kristof Schmieden; Professor Dr. Matthias Schott
• Cooperation Partner: Professor Dr. Henryk Czyz
• Ehemalige Antragstellerin: Lena Heijkenskjöld, Ph.D., until 1/2023