Workshop of the Research Unit FOR5327 in St. Goar
From June 11 to 13, 2025, the members of the Research Unit FOR5327 gathered for a workshop at Schloss Rheinfels in St. Goar, a historic castle overlooking the Rhine River. The meeting brought together researchers from all five projects of the Research Unit (TFF, XYZ, LBL, ALP, and JRP) to discuss recent progress and to coordinate the next steps in the ongoing collaborations. Several guests, including speakers from Japan and the USA, presented additional information on future two-photon measurements, e.g., at JLAB and BELLEII.
The workshop provided a valuable opportunity to share results and strengthen the synergy between theoretical and experimental groups working on photon-photon interactions. In preparation for the upcoming proposal for a second funding period, the teams reviewed the scientific achievements of the past years and outlined future research goals. The beautiful environment of the Rhine Valley offered a perfect setting for a successful workshop full of fruitful discussions.
New research unit at JGU granted DFG funding
Photon-photon interactions in the Standard Model and beyond - A pure quantum effect as the key to a better understanding of the subatomic world
April 11, 2022
In classical physics, the superposition of light waves resulting in interference is a well-known phenomenon. An interaction of light rays in the sense of a scattering is, however, classically impossible. Conversely, in the subatomic world, which is described by quantum effects, the quantum particles of light – known as photons – do indeed interact with each other. Moreover, photon-photon interactions play a crucial role in the Standard Model of particle physics. A better understanding of this pure quantum effect is the key to gaining important new insights both within the Standard Model as well as beyond it. This photon-photon interaction is the focus of a new research unit at Johannes Gutenberg University Mainz (JGU). Funding for the research unit has just been approved by the German Research Foundation (DFG); the DFG will initially provide roughly 3.5 million Euros over the next four years. The spokesperson of the research unit is Professor Achim Denig, an experimental physicist and the co-spokesperson is Professor Marc Vanderhaeghen, a theoretical physicist, both of whom work at JGU's Institute of Nuclear Physics.
More information is available in the press release.