Recent Results from KATRIN and Beyond
by
LIP-Lisboa/3-311 - Sala de Seminários
LIP Lisboa
The KATRIN experiment probes the neutrino mass through a precise integral measurement of the tritium spectrum near the kinematic endpoint. In 2025, we published a new world-leading upper limit of 0.45 eV (90% C.L.) based on the first five measurement campaigns. New operational conditions that improve the signal-to-background ratio, the steady reduction of systematic uncertainties, and a substantial increase in statistics now allow us to extend this sensitivity. Although KATRIN is expected to complete data-taking this year, we have published less than 20% of the collected dataset and expect the limit to be further reduced to around 0.3 eV.
In 2026, KATRIN will be upgraded to the TRISTAN phase, with the goal of measuring the full tritium differential spectrum to search for keV-scale sterile neutrinos. Sterile neutrinos are predicted in many theories and, in the mass range of a few keV, are considered strong dark matter candidates. Given the very large statistics to be collected (more than 10^15 events), TRISTAN will require exceptionally tight control of systematic uncertainties.
Following TRISTAN, the KATRIN++ program will initiate a research and development phase to design concepts for a next-generation experiment capable of even more precise direct neutrino mass measurements. Our aim is to replace the current molecular tritium source with an atomic source and to replace the detectors with state-of-the-art quantum sensors with sensitivities on the order 1 eV.