Search for keV-scale sterile neutrinos with the first KATRIN data

Abstract In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium...

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Bibliographic Details
Main Authors: Aker, M., Batzler, D., Beglarian, A., Behrens, J., Berlev, A., Besserer, U., Bieringer, B., Block, F., Bobien, S., Bornschein, B., Bornschein, L., Böttcher, M., Brunst, T., Caldwell, T. S., Chilingaryan, S., Choi, W., Debowski, K., Descher, M., Barrero, D. D., Doe, P. J.
Other Authors: Massachusetts Institute of Technology. Laboratory for Nuclear Science
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2023
Online Access:https://hdl.handle.net/1721.1/152195
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Summary:Abstract In this work we present a keV-scale sterile-neutrino search with a low-tritium-activity data set of the KATRIN experiment, acquired in a commissioning run in 2018. KATRIN performs a spectroscopic measurement of the tritium $$\upbeta $$ β -decay spectrum with the main goal of directly determining the effective electron anti-neutrino mass. During this commissioning phase a lower tritium activity facilitated the measurement of a wider part of the tritium spectrum and thus the search for sterile neutrinos with a mass of up to $$1.6\, \textrm{keV}$$ 1.6 keV . We do not find a signal and set an exclusion limit on the sterile-to-active mixing amplitude of $$\sin ^2\theta < 5\times 10^{-4}$$ sin 2 θ < 5 × 10 - 4 ( $$95\%$$ 95 % C.L.) at a mass of 0.3 keV. This result improves current laboratory-based bounds in the sterile-neutrino mass range between 0.1 and 1.0 keV.