000003599 001__ 3599
000003599 005__ 20230524074057.0
000003599 037__ $$aBELLE2-MTHESIS-2023-016
000003599 041__ $$aeng
000003599 100__ $$aOri Israel Fogel
000003599 245__ $$aSearch for a heavy neutral lepton that mixes predominantly with the tau neutrino
000003599 260__ $$aTel Aviv $$bTel Aviv University$$c2023
000003599 300__ $$a67
000003599 500__ $$aPresented on 28 02 2023
000003599 502__ $$aMSc$$bTel Aviv , Tel Aviv University$$c2023
000003599 520__ $$aHeavy neutral leptons (HNLs) are highly motivated as a solution to the problems of neutrino masses, dark matter and the baryon asymmetry of the universe. In light of tight limits set by previous searches for HNLs that mix with electron and muon neutrinos, we search for an HNL that mixes predominantly with the tau neutrino. Such an HNL can be produced in tau decays, which are best studied in B-factory experiments. We search for the HNL in a sample of 8.8x10^8 e+e− → τ +τ − events collected by the Belle experiment at center-of-mass energies around 10.58 GeV. The search focuses on long-lived HNLs with mass in the range 0.3-1.6 GeV exploiting the displaced-vertex signature for suppressing background. We set a new expected limit on the mixing between the HNL and ντ .
000003599 700__ $$aAbner Soffer$$edir.
000003599 8560_ $$fisraelorif@mail.tau.ac.il
000003599 8564_ $$uhttps://docs.belle2.org/record/3599/files/BELLE2-MTHESIS-2023-016.pdf
000003599 980__ $$aTHESIS