Measurement of $B^{+}\to {\tau }^{+}{\nu }_{\tau }$ branching fraction with a hadronic tagging method at Belle II

Abstract

We present a measurement of the branching fraction of $B^{+}\to {\tau }^{+}{\nu }_{\tau }$ decays using $(387\pm 6)\times 10^6$ ${\rm Y}(4S)$ collected between 2019 and 2022 with the Belle II detector at the SuperKEKB $e^{+}{e}^{-}$ collider. We reconstruct the accompanying $B^{-}$ meson using the hadronic tagging method, while $B^{+}\to {\tau }^{+}{\nu }_{\tau }$ candidates are identified in the recoil. We find evidence for $B^{+}\to {\tau }^{+}{\nu }_{\tau }$ decays at 3.0 standard deviations, including systematic uncertainties. The measured branching fraction is $\mathcal{B}(B^{+}\to {\tau }^{+}{\nu }_{\tau })=[1.24\pm 0.41(\text{stat.})\pm 0.19(\text{syst.})]\times 10^{-4}$.

References in corpus (18)

• An Introduction to PYTHIA 8.2
• The Precision Monte Carlo Event Generator KK For Two-Fermion Final States In e+e- Collisions
• The Physics of the B Factories
• Update of the global electroweak fit and constraints on two-Higgs-doublet models
• SuperKEKB Collider
• Explaining B->Dτν, B->D*τνand B->τνin a 2HDM of type III
• The Belle II Core Software
• Evidence for B- -> tau- nu_tau-bar with a Hadronic Tagging Method Using the Full Data Sample of Belle
• Charged-Higgs phenomenology in the Aligned two-Higgs-doublet model
• Evidence of B-->tau nu decays with hadronic B tags
• The Full Event Interpretation -- An exclusive tagging algorithm for the Belle II experiment
• A Search for B+ -> tau+ nu Recoiling Against B- -> D0 l- nu X
• A Search for $B^{+}\to {\ell }^{+}{\nu }_{\ell }$ Recoiling Against $B^{-}\to D^0{\ell }^{-}\bar{\nu }X$
• Improved Constraints on Sterile Neutrinos in the MeV to GeV Mass Range
• The Design, Construction, Operation and Performance of the Belle II Silicon Vertex Detector
• Front-end electronic readout system for the Belle II imaging Time-Of-Propagation detector
• Measurement of the integrated luminosity of data samples collected during 2019-2022 by the Belle II experiment
• ALP production in weak mesonic decays

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