Neutrinos probably are the most fascinating species of elementary particles. The "ghost particle of the Universe" is a key to open issues in science on many scales, linking the microcosm of elementary particles to the largest structures in the Universe. They are the most abundant and also the lightest matter particle in the Universe, with a mass at least a million times lighter than electrons, the second lightest particle known so far. While their tiny mass is a clear indication for physics beyond the standard model of elementary particle physics, the exact value of this mass is still unknown.
The KArlsruhe TRItium Neutrino (KATRIN) experiment has been measuring the specific reaction of β-decay of tritium since 2019 in order to determine the effective mass of the electron antineutrino. Earlier this year the collaboration was able to present release a leading limit on the neutrino mass to date.
Now, the experiment reached another benchmark: on Oct 26th KATRIN accomplished its goal of 1000 measurement days of probing the endpoint region of the tritium beta-decay spectrum with unprecedented sensitivity, marking the completion of its neutrino-mass data taking. While the analysis of the full dataset is still ongoing, the completion of this measurement phase represents an important milestone in its operation. Starting in 2026, a new detector system, TRISTAN, will be installed. This upgrade to the experiment will enable the search for sterile neutrinos, a hypothetical particle, which interacts even more feebly than the known neutrinos but is a potential candidate for dark matter. TRISTAN is developed and currently under construction led by the team at the Max-Planck-Institut für Kernphysik in Heidelberg.
The international KATRIN Collaboration unites world-wide expertise in tritium-β-decay in a key experiment in the research field of astroparticle physics and consists of more than 150 scientists, engineers, technicians and students from all over the world.
Further references:
KATRIN Website: http://www.katrin.kit.edu
