000004161 001__ 4161
000004161 005__ 20240311040540.0
000004161 037__ $$aBELLE2-TALK-CONF-2024-030
000004161 041__ $$aeng
000004161 088__ $$aBELLE2-TALK-DRAFT-2024-017
000004161 100__ $$aRashmi Dhamija
000004161 245__ $$aSearch for LFV in Y(2S) --> l tau
000004161 260__ $$aQWG 2024 - The 16th International Workshop on Heavy Quarkonium$$c2024-02-26
000004161 300__ $$amult. p
000004161 520__ $$aWe report a search for the charged-lepton flavor violation in $\Upsilon(2S)\to \ell^{\mp}\tau^{\pm} (\ell= e,\mu)$ decays using a 25 $\rm{fb}^{-1} \Upsilon(2S)$ sample collected by the Belle detector at the KEKB $e^{-}e^{+}$ asymmetric-energy collider. We find no evidence for a signal and set upper limits on the branching fractions (B) at a 90% confidence level. We obtain the most stringent upper limits: $\mathcal{B}(\Upsilon(2S) \to \mu^{\mp}\tau^{\pm}) < 0.23 × 10^{-6}$ and $\mathcal{B}(\Upsilon(2S) \to e^{\mp}\tau^{\pm}) < 1.12 × 10^{-6}$.
000004161 8560_ $$fdjaffe@bnl.gov
000004161 8564_ $$uhttps://docs.belle2.org/record/4161/files/BELLE2-TALK-CONF-2024-030.pdf