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 endpoint at 18.57
keV gives an effective neutrino mass square value of $(-1.0^{+0.9}_{-1.1})$
eV$^2$. 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 factor of two and provides model-independent input to cosmological
studies of structure formation.
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
REGISTER
Did you like this article? 
