Particle Physics Seminar
"First KATRIN results: neutrino mass and search for light sterile neutrinos"
Presented by Dr Thierry Lasserre, CEA/DSM/IRFU; Laboratorie APC; IAS Technische Universität München
Thursday, January 21, 2021, 3:00 pm — Webcast
Abstract: I will report on the neutrino mass analysis and on the light sterile neutrino search from the first four-week science run of the KATRIN experiment. Beta-decay electrons from a high-purity gaseous molecular tritium source are analyzed by a high-resolution MAC-E filter down to 40 eV below the endpoint at 18.57 keV. The analysis of the spectral shape of the spectrum near the endpoint leads to an improvement over previous direct measurement of the neutrino mass, with a new upper limit of 1.1 eV at 90% C.L. Analyzing the shape of the whole spectrum down to 40 eV below the endpoint, we find no significant distortion compared to the standard model expectation. Therefore, exclusion bounds on the sterile mass and mixing are reported. These new limits supersede the Mainz results and improve the Troitsk bound. The reactor and gallium anomalies are further constrained.
Hosted by: Hanyu Wei
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