Orateur
Description
The fact that neutrinos have a nonzero rest mass would provide clear evidence of physics beyond the Standard Model, with wide-reaching implications in both particle physics and cosmology. The KATRIN (Karlsruhe Tritium Neutrino) experiment aims to determine the absolute neutrino mass scale by performing high-precision spectroscopy of electrons emitted in tritium beta decay near the kinematic endpoint. In this contribution, we present results from the analysis of the first five measurement campaigns. Utilizing a data set collected over 259 days, along with substantially reduced background levels and improved control of systematic uncertainties, we determined best-fit value of m_ν^2=-0.14_(-0.15)^(+0.13) eV^2. This yields a new upper limit on the effective electron antineutrino mass of m_ν<0.45 eV at 90% confidence level. This result improves KATRIN’s previous limit by nearly a factor of two and establishes a new benchmark for direct neutrino mass measurements.
