Abstract

Precision measurements of the kinematics of weak decays offer a direct and nearly model-independent approach to probe the absolute neutrino mass scale. The KArlsruhe TRItium Neutrino experiment (KATRIN) is searching for the minute imprint of the neutrino mass in the endpoint region of the tritium beta-decay spectrum. KATRIN [1] employs a high-intensity gaseous molecular tritium source and a high-resolution electrostatic filter with magnetic adiabatic collimation to target a neutrino-mass sensitivity of 0.2 eV/c2, thus improving on previous experiments by an order of magnitude, after five years of data-taking. This talk presents the results of the first science run of KATRIN in which an initial dataset of a few weeks allows to tighten the direct neutrino mass bound by about a factor of 2 already, yielding a new upper limit of 1.1 eV/c2 (90% CL) [2]. The successful first campaign gives promising perspectives on the long-term data harvest to exploit KATRIN's neutrino mass sensitivity goal and to open up further interesting science channels in the search for physics beyond the Standard Model.  References: [1] KATRIN Collaboration, "First operation of the KATRIN experiment with tritium", EPJ C 80 (2020) 264 [doi.org] [2] KATRIN Collaboration, "Improved upper limit on the neutrino mass from a direct kinematic method by KATRIN", PRL 123 (2019) 221802 [journals.aps.org]