Research Focus: Strongly Interacting Matter

The research in our group is concentrating on the study of matter at extreme density or temperature, where the strong nuclear interaction, one of the four fundamental forces in nature, dominates the behavior. The most striking theoretical prediction for such conditions is the existence of a new state of matter for temperatures larger 1000000000000 degrees (1012K), the quark-gluon plasma. As such temperatures should have existed in the universe in the first 10 microseconds after the big bang, this state is important to understand the early universe.

We can reach similar conditions in the laboratory for very short times by colliding atomic nuclei at very high energies. We perform measurements in such collisions at particle accelerators like the Large Hadron Collider (LHC) at CERN within the ALICE experiment. In addition to the creation of the extremely hot quark-gluon plasma in the collisions, the experiment allows us to study the properties of nuclei at very high energy just before the collision. Under these circumstances the nuclei are thought to be in another extreme condition of high density, the so-called color-glass condensate.

These interesting states of extreme matter, which can tells us a lot about the fundamental properties of the strong interaction, have a fleeting existence in our laboratories. The collisions are comparable to a “Little Bang”: a system consisting of thousands of new particles is created and explodes. We measure the debris of these events and reconstruct the early extreme stages from the particles emerging from the little explosions and reaching our detectors.

These measurements are extremely challenging. Our institute contributes to the measurements themselves and has a strong effort in data analysis on a number of crucial research questions on strongly interacting matter. In addition we are active in the development, design and construction of the newest particle detector technologies, which are needed in the experiments.