000004057 001__ 4057
000004057 005__ 20240111074921.0
000004057 037__ $$aBELLE2-PUB-PH-2024-001
000004057 041__ $$aeng
000004057 088__ $$aBELLE2-NOTE-PH-2022-032
000004057 088__ $$aBELLE2-PUB-DRAFT-2023-015
000004057 100__ $$aThe Belle II Collaboration
000004057 245__ $$aA test of lepton flavor universality with a measurement of $R(D^{*})$ using hadronic $B$ tagging at the Belle~II experiment
000004057 260__ $$a$$c2024-01-05
000004057 300__ $$a16
000004057 520__ $$aThe ratio of branching fractions $R(D^{*}) = \mathcal{B}(\overline{B} \rightarrow D^{*} \tau^{-} \overline{\nu}_{\tau})$/$\mathcal{B} (\overline{B} \rightarrow D^{*} \ell^{-} \overline{\nu}_{\ell})$, where $\ell$ is an electron or muon, is measured using a Belle~II data sample with an integrated luminosity of $189~\mathrm{fb}^{-1}$ at the SuperKEKB asymmetric-energy $e^{+} e^{-}$ collider. Data is collected at the $\Upsilon(\mathrm{4S})$ resonance, and one $B$ meson in the  $\Upsilon(\mathrm{4S})\rightarrow B\overline{B}$ decay is fully reconstructed in hadronic decay modes. The accompanying signal $B$ meson is reconstructed as $\overline{B}\rightarrow D^{*} \tau^{-}\overline{\nu}_{\tau}$ using leptonic $\tau$ decays. The normalization decay, $\overline{B}\rightarrow D^{*} \ell^{-} \overline{\nu}_{\ell}$ produces the same observable final state particles. The ratio of branching fractions is extracted in a simultaneous fit to two signal-discriminating variables in both channels and yields $R(D^{*}) = 0.262~_{-0.039}^{+0.041}(\mathrm{stat})~_{-0.032}^{+0.035}(\mathrm{syst})$. This result is consistent with the current world average and with standard model predictions.
000004057 6531_ $$aR(D*)
000004057 6531_ $$aD*taunu
000004057 6531_ $$aFEI
000004057 6531_ $$aHadronic tag
000004057 6531_ $$aLeptonic tau decay
000004057 6531_ $$aSemileptonic
000004057 6531_ $$aSemitauonic
000004057 8560_ $$fkojima@hepl.phys.nagoya-u.ac.jp
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/BELLE2-PUB-PH-2024-001.pdf$$yarXiv:2401.02840
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure1.pdf$$yFigure1
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure2a.pdf$$yFigure2a
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure2b.pdf$$yFigure2b
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure3.pdf$$yFigure3
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure4a.pdf$$yFigure4a
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure4b.pdf$$yFigure4b
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure4c.pdf$$yFigure4c
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5a.pdf$$yFigure5a
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5b.pdf$$yFigure5b
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5c.pdf$$yFigure5c
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5d.pdf$$yFigure5d
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5e.pdf$$yFigure5e
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure5f.pdf$$yFigure5f
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure6a.pdf$$yFigure6a
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure6b.pdf$$yFigure6b
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure6c.pdf$$yFigure6c
000004057 8564_ $$uhttps://docs.belle2.org/record/4057/files/Figure7.pdf$$yFigure7