Ori Israel Fogel ; Abner Soffer

2023
Tel Aviv University Tel Aviv

Abstract: Heavy neutral leptons (HNLs) are highly motivated as a solution to the problems of neutrino masses, dark matter and the baryon asymmetry of the universe. In light of tight limits set by previous searches for HNLs that mix with electron and muon neutrinos, we search for an HNL that mixes predominantly with the tau neutrino. Such an HNL can be produced in tau decays, which are best studied in B-factory experiments. We search for the HNL in a sample of 8.8x10^8 e+e− → τ +τ − events collected by the Belle experiment at center-of-mass energies around 10.58 GeV. The search focuses on long-lived HNLs with mass in the range 0.3-1.6 GeV exploiting the displaced-vertex signature for suppressing background. We set a new expected limit on the mixing between the HNL and ντ .

Note: Presented on 28 02 2023
Note: MSc