The German Research Foundation (DFG) has approved a new research unit for the “Determination of the neutrino mass hierarchy with the JUNO experiment”, in which the team led by Mainz physicist Prof. Dr. Michael Wurm is involved. The research unit is investigating the question of the hierarchy or order of neutrino masses, i.e. which of the three known neutrino species has the lowest and which has the heaviest mass. With the development of the liquid scintillator, in which neutrinos are detected in experiments via the flashes of light they produce, the group is participating in the construction of the new neutrino detector in southern China. More than 50 institutes from China, the USA and Europe are involved in the Jiangmen Underground Neutrino Observatory (JUNO), six of them from Germany alone. The new research unit “Clause of the neutrino mass hierarchy with the JUNO experiment” is headed by RWTH Aachen University.

The Mainz work group’s contribution to JUNO covers two aspects of detector development. “On the one hand, we are involved in the preparation of data analysis and detector simulations, providing important feedback for the design of the neutrino detector. On the other hand, we are involved in optimizing the liquid scintillator and thus the detection medium for the neutrinos, especially with regard to optical transparency and the exact chemical composition,” explains Michael Wurm. Both aspects contribute significantly to the experimental sensitivity and thus to the success of the JUNO experiment.

Neutrino physics has been an important field of research in Particle Physics, and not just since this year’s Nobel Prize in Physics was awarded for proving that neutrinos have mass. At the Precision Physics, Fundamental Interactions and Structure of Matter (PRISMA) Cluster of Excellence at Johannes Gutenberg University Mainz (JGU), neutrino physics plays an important role in the research program on the weakly interacting universe.