Gamma-gamma physics and meson structure ((06) M01)

• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2012 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 204404729

A detailed study of meson structure using two-photon processes provides the necessary input to constrain the hadronic light-by-light (HLbL) contribution to the anomalous magnetic moment of the muon (g-2). These corrections are currently, together with the hadronic vacuum polarization, the leading uncertainties in the standard model prediction for (g-2). On the other hand, these studies provide one of the cleanest probes of the structure of mesons, allowing to extract the transition form factors of single mesons and of multi-meson systems, as well as the pion polarizabillities. To access these quantities requires a strong interplay between theoretical and experimental efforts, which are both represented in this project.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1044: The Low-Energy Frontier of the Standard Model: From Quarks and Gluons to Hadrons and Nuclei
• Applicant Institution: Johannes Gutenberg-Universität Mainz
• Project Heads: Professor Dr. Achim Denig; Professor Dr. Marc Vanderhaeghen