Center for Underground Physics

 

Since beginning scientific operations in 2019, the Karlsruhe Tritium Neutrino (KATRIN) experiment has accumulated 1,000 days of data to determine the absolute neutrino-mass scale. Using a magnetic adiabatic collimation with an electrostatic (MAC-E) filter, KATRIN has measured the integrated tritium beta-decay spectrum near its endpoint with an energy resolution of about 1 eV. A recent analysis of the first quarter of the data yielded an upper limit on the neutrino mass of 0.45 eV (90% CL), representing the most stringent laboratory constraint to date. Project 8, on the other hand, has developed a new high-resolution technique called cyclotron radiation emission spectroscopy (CRES) together with the atomic tritium source. By employing these emerging techniques, Project 8 aims to measure the neutrino-mass scale with a sensitivity of approximately 40 meV. In this talk, I will present the history of KATRIN, its latest results from the 259-day dataset, and the sensitivity from the full 1,000-day dataset. I will also discuss the status and plans of Project 8 and outline the prospects of neutrino mass measurements.