Calorimetric Study Sets New Limit on Electron Neutrino Mass
The HOLMES experiment has set the most stringent upper limit on the electron neutrino mass at less than 27 eV/c² using a scalable calorimetric approach with microcalorimeters measuring holmium-163 decay, validating long-term experimental techniques and paving the way for future sub-eV sensitivity in neutrino mass measurements.