2025/02/03 by KM3NeT Collaboration, S. Aiello, Aiello, S. +364 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Neutrino Physics Research
paper · pdf · doi:10.48550/arxiv.2502.01443
openalex publication_date 2025/02/03 · openalex created_date 2025/02/06 · openalex updated_date 2026/07/30
Oscillations of atmospheric muon and electron neutrinos produce tau neutrinos with energies in the GeV range, which can be observed by the ORCA detector of the KM3NeT neutrino telescope in the Mediterranean Sea. First measurements with ORCA6, an early subarray corresponding to about 5% of the final detector, are presented. A sample of 5828 neutrino candidates has been selected from the analysed exposure of 433 kton-years. The ντ normalisation, defined as the ratio between the number of observed and expected tau neutrino events, is measured to be Sτ= 0.48+0.5-0.33. This translates into a ντ charged-current cross section measurement of στmeas = (2.5 +2.6-1.8) × 10-38 cm2 nucleon-1 at the median ντ energy of 20.3 GeV. The result is consistent with the measurements of other experiments. In addition, the current limit on the non-unitarity parameter affecting the τ-row of the neutrino mixing matrix was improved, with α33> 0.95 at the 95% confidence level.