Search for lepton flavor violating decay $B^0 \rightarrow K^{*0} \tau \ell$ using the Belle and Belle II data sample
| Abstract | We present the results of a search for the charged-lepton-flavor violating decays $B^{0} \to K^{*0} \tau^{\pm}\ell^{\mp}$, where $\ell^{\mp}$ is either an electron or a muon. The results are based on 365 fb$^{−1}$ and 711 fb$^{−1}$ datasets collected with the Belle II and Belle detectors, respectively. We use an exclusive hadronic $B$-tagging technique, and search for the signal decay in the system recoiling against the fully reconstructed $B$ meson. We find no evidence for $B^{0} \to K^{*0} \tau^{\pm}\ell^{\mp}$ decays and set upper limits on the branching fractions in the range of (2.9–6.4)$\times 10^{-5}$ at 90% confidence level. |
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| Tags | Run 1 Belle |
| Working group | Radiative and Electroweak Penguin |
| Principal authors | @ Valerio Bertacchi, Clotilde Lemettais, Giampiero Mancinelli, Justine Serrano |
| Reference | published in JHEP |
| Document | BELLE2-PUB-PH-2025-012 |
| Links | arXiv:2505.08418, |