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Cosmological and astrophysical bounds on a heavy sterile neutrino and the KARMEN anomaly

A. D. Dolgov·S. H. Hansen·G. Raffelt·D. V. Semikoz
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Abstract

Constraints on the lifetime of the heavy sterile neutrino, that was proposed as a possible interpretation of the KARMEN anomaly, are derived from primordial nucleosynthesis and SN 1987A. Together with the recent experimental bounds on the nu_s lifetime, SN 1987A completely excludes this interpretation. Nucleosynthesis arguments permit a narrow window for the lifetime in the interval 0.1-0.2 sec. If nu_s possesses an anomalous interaction with nucleons, the SN bounds may not apply, while the nucleosynthesis ones would remain valid.

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A. D. Dolgov, S. H. Hansen, G. Raffelt, D. V. Semikoz. 2000-02-27. Cosmological and astrophysical bounds on a heavy sterile neutrino and the KARMEN anomaly. https://doi.org/10.1016/s0550-3213(00)00203-0

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