Big Bang and Ghost Particles


The German Research Foundation DFG has established new Research Units involving researchers from two RWTH Aachen institutes.


Professor Achim Stahl from the Chair of Experimental Physics III B is spokesperson for the Research Unit, which seeks to unravel the secrets of neutrinos, the most mysterious of the elementary particles. Professors Michael Krämer and Robert Harlander, both from the Institute of Theoretical Particle Physics and Cosmology, will investigate philosophical questions surrounding the experiments at the “world machine,” the large hadron collider at CERN in Geneva.

Over the next three years, the interdisciplinary Research Unit "Epistemology of the Large Hadron Collider,” physicists, historians, sociologists, and philosophers from Germany, Austria and the United States will analyze recent developments in particle physics.

The focus is not so much on current research activities, but rather on a philosophical reflection of research approaches and questions concerning the possible replacement of the standard model of nature by a more fundamental theory. As Michel Krämer puts it, “It’s about how to gain new insights and also about the question whether established philosophical concepts are still adequate in view of current research results.”

In this unique project, Krämer and his colleague Harlander will address the philosophical aspects of phenomena such as the Higgs particle and dark matter, topics which have been at the focus of research at RWTH Aachen with the aim of developing new explanations of the origins of the universe after the Big Bang.

"Poltergeist" Particles Pass Through Matter

The Research Unit “Determination of Neutrino Mass Hierarchy in the JUNO Experiment” is a German-Chinese collaborative project hosted by RWTH Aachen Uniersity. In collaboration with Forschungszentrum Jülich, TU Munich, and the universities of Hamburg, Mainz, and Tübingen, Professor Stahl’s group will contribute to building the JUNO detector, which seeks to investigate the role of the elusive neutrino particles. These “poltergeist" particles are able to pass through matter almost without interacting with it at all, and this is why it is so hard to detect them experimentally.

For the Jiangmen Underground Neutrino Observatory, JUNO for short, a giant tank will be built containing 20,000 liters of a special oil-like target liquid. A total of about 18,000 highly sensitive photo sensors will continuously observe the contents of the tank. The tank is located in a depth of 700 meters and is shielded from distracting cosmic rays through layers of rock.

The research group seeks to develop intelligent electronics to digitize and store the vast amount of data generated by the detector, which is to observe neutrinos from several sources: First, there are neutrinos from several nuclear reactors located about 55 kilometers from JUNO. Then, there are those emitted by the Sun, which might enhance our understanding of energy generation in the Sun. Furthermore, there are neutrinos from exploding stars and neutrinos from the Earth’s core, which help to deepen our understanding of the composition of the Earth.