“The Color meets Flavor Cluster of Excellence is a striking example of the strength of basic research in North Rhine-Westphalia,” Ina Brandes, Minister of Science and Research, pointed out at the inauguration. “The question of matter versus antimatter, i.e. why things exist rather than there simply being nothing there, is one of the as-yet unsolved riddles of our Universe. The joint Cluster of Excellence involving the Universities of Bonn and Siegen, TU Dortmund and Forschungszentrum Jülich is flying the flag for top-level research made in NRW.”
“The Color meets Flavor Cluster of Excellence stands for pure, unbridled joy in science, top-level research and an internationality that is actively embraced. It is tackling the major unanswered questions of our very existence, such as how matter is created, what fundamental forces and mechanisms act on this process and how we can get closer to unraveling the remaining mysteries of nature,” Rector Michael Hoch explained. “The opening of what is now our eighth Cluster of Excellence is at once a truly special moment for us and an impressive demonstration of the excellent research environment that North Rhine-Westphalia boasts. This is reflected in particular in the extremely close working relationship between the four sites and in the successful mix of early-career and seasoned researchers who are working on this project and propelling it forward.”
Cluster speaker Professor Jochen Dingfelder from the University of Bonn describes the two-year application process as an adventure: “We’ve shared some unforgettable moments together and managed to turn a highly promising idea into a full-fledged cluster that’s built on many years’ scientific collaboration in various fields of particle physics—but also, and most importantly, on longstanding friendships. So we feel that this cluster was long overdue.”
Physics, but make it aerobatic
It was not only through the actual science that the physicists amazed the audience with their research: The content of the short talks given on the cluster’s four research areas was brought to life through acrobatics thanks to Professor Alexander Lenz (University of Siegen), one of the cluster’s co-speakers, together with his family: Dressed as quarks, the fundamental elementary particles that make up matter in the Universe, they offered up a vivid demonstration of how the different flavors of quark—up, down, strange, beauty, charm and top—interact with one another.
Following the opening ceremony, booths set out in the foyer of the lecture hall provided information about the cluster’s research work, such as INSIGHT, a flagship project to which all four cluster partners are contributing. The INSIGHT experiment is being set up at the Electron Stretcher Accelerator (ELSA) at the University of Bonn for researchers to investigate the properties of baryons—a family of particles that includes protons and neutrons—much more precisely than they ever have before. For this they are using ELSA, the highest-energy accelerator at any university in Europe, coupled with innovative measurement methods. This combination—the only one of its kind in the world—is opening up new possibilities, most notably for gaining a better understanding of baryons containing “strange” quarks.
About the Cluster of Excellence: the color and flavor of physics
Color and flavor represent two fundamental forces of nature, referred to as the strong (“color”) and weak (“flavor”) interactions. Together with their partners, the particle physicists at the University of Bonn intend to study the relationship between the strong and weak interactions in order to discover new physical phenomena and answer the really big questions: “Why is there only matter in the Universe, and how does the strong interaction bring it into being?” “And what is the secret of dark matter, which is believed to constitute the bulk of what makes up the Universe?”
The researchers will be focusing specifically on quarks, the fundamental building blocks of matter. It is the strong interaction that holds them together and forms them into hadrons such as protons and neutrons, i.e. the component parts of nuclei. Meanwhile, the weak interaction is what enables particles to change their type (“flavor”), e.g. when a neutron decays into a proton, an electron and an antineutrino. Processes like this furnish important insights into the properties of particles—including potentially new ones that have so far eluded discovery. The Cluster of Excellence will also be studying the properties of the Higgs boson and searching for the axion, a hypothetical particle that plays a key role in the strong interaction and could also be a candidate for dark matter.
The eight Clusters of Excellence at the University of Bonn
With the inauguration of Color meets Flavor, the University of Bonn’s eighth Cluster of Excellence has now also officially begun its work; its funding has been running since January 2026. Details of all eight clusters can be found at https://www.uni-bonn.de/en/research-and-teaching/research-profile/excellence-strategy/clusters-of-excellence.
