0000000000654095
AUTHOR
B. Flatt
Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN
We report on the neutrino mass measurement result from the first four-week science run of the Karlsruhe Tritium Neutrino experiment KATRIN in spring 2019. Beta-decay electrons from a high-purity gaseous molecular tritium source are energy analyzed by a high-resolution MAC-E filter. A fit of the integrated electron spectrum over a narrow interval around the kinematic end point at 18.57 keV gives an effective neutrino mass square value of (−1.0−1.1+0.9) eV2. From this, we derive an upper limit of 1.1 eV (90% confidence level) on the absolute mass scale of neutrinos. This value coincides with the KATRIN sensitivity. It improves upon previous mass limits from kinematic measurements by almost a …
Status of the Neutrino Mass Experiment KATRIN
The KArlsruhe TRItium Neutrino experiment KATRIN is an international next-generation direct neutrino mass experiment, which will improve the current neutrino mass sensitivity in tritium decay by one order of magnitude. This report describes the status of hardware components and results of prototype measurements (supported in part by the German BMBF No. 5CK1VK1/7, 05CK1UM1/5 and 05CK2PD1/5).