000003548 001__ 3548
000003548 005__ 20230515094955.0
000003548 037__ $$aBELLE2-CONF-PROC-2023-010
000003548 041__ $$aeng
000003548 100__ $$aLaura Zani
000003548 245__ $$aDark sectors and τ physics at Belle II
000003548 260__ $$a$$c2023-05-02
000003548 300__ $$a4
000003548 520__ $$aThe possibility of dark sectors weakly coupling to Standard Model (SM) particles through new light mediators is explored at the Belle II experiment. We present here results from three different searches, for a long-lived (pseudo)scalar particle; for a di-tau resonance in four-muon final states events and the update on the search for a Z′ boson decaying invisibly in events with two muons plus missing energy, performed on samples from the data collected by the Belle II detector during 2019-2021 data taking. We report the search for τ → ℓα decays, with α a new invisible boson, and the first successful untagged reconstruction of tau pairs events searching for the neutrinoless decays τ → ℓφ. Finally, we present the world’s most precise measurement of the τ lepton mass.
000003548 6531_ $$aMoriond QCD23
000003548 8560_ $$flaura.zani@roma3.infn.it
000003548 8564_ $$uhttps://docs.belle2.org/record/3548/files/BELLE2-CONF-PROC-2023-010.pdf
000003548 8564_ $$uhttps://docs.belle2.org/record/3548/files/%20BELLE2-CONF-PROC-2023-010%20%28submitted%29.pdf