Search for lepton flavor-violating decay modes $B^0\to K^{\ast 0}{\tau }^{\pm }{\ell }^{\mp }$ ($\ell =e,\mu$) with hadronic B-tagging at Belle and Belle II

Abstract

We present the results of a search for the charged-lepton-flavor violating decays $B^0\to K^{\ast 0}{\tau }^{\pm }{\ell }^{\mp }$, 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 a signal decay in the system recoiling against a fully reconstructed $B$ meson. We find no evidence for $B^0\to K^{\ast 0}{\tau }^{\pm }{\ell }^{\mp }$ decays and set upper limits on the branching fractions in the range of $(2.9-6.4)\times 10^{-5}$ at 90% confidence level.

arXiv comment19 pages, 4 figures

References in corpus (16)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• An Introduction to PYTHIA 8.2
• Asymptotic formulae for likelihood-based tests of new physics
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• SuperKEKB Collider
• Lepton-flavour violating $B$ decays in generic $Z^{\prime }$ models
• The Belle II Core Software
• Evidence for B0->pi0pi0
• On the single leptoquark solutions to the $B$-physics anomalies
• Leptoquark Flavor Patterns & B Decay Anomalies
• Lepton Flavor Violation in Exclusive $b\to s$ Decays
• The Full Event Interpretation -- An exclusive tagging algorithm for the Belle II experiment
• B2BII - Data conversion from Belle to Belle II
• Front-end electronic readout system for the Belle II imaging Time-Of-Propagation detector
• Measurements of Beam Backgrounds in SuperKEKB Phase 2