000003744 001__ 3744
000003744 005__ 20230718181640.0
000003744 037__ $$aBELLE2-CONF-PROC-2023-029
000003744 041__ $$aeng
000003744 088__ $$aBELLE2-TALK-CONF-2023-025
000003744 100__ $$aKazuki Kojima
000003744 245__ $$aBelle~II results related to $b \to c$ anomalies
000003744 260__ $$a$$c2023-07-17
000003744 300__ $$a4
000003744 500__ $$aContribution to the 2023 Electroweak session of the 57th Rencontres de Moriond
000003744 520__ $$aWe report two new measurements for tests of lepton flavor universality between electrons and muons using semileptonic $B$ decays with a data set of $189~\mathrm{fb}^{-1}$ collected at the Belle II experiment between 2019 and 2021. Firstly, we find a ratio of inclusive branching fractions at $R(X_{e/\mu}) \equiv \mathcal{B}(\overline{B} \rightarrow Xe^{-}\overline{\nu}_{e})/\mathcal{B}(\overline{B} \rightarrow X\mu^{-}\overline{\nu}_{\mu}) = 1.007 \pm 0.009 (\mathrm{stat.}) \pm 0.019 (\mathrm{syst.})$. This inclusive measurement leads to the most precise universality test based on branching fractions. The measured $R(X_{e/\mu})$ is consistent with the Standard-Model prediction. Secondly, we measure a comprehensive set of five angular asymmetries of $\overline{B}^{0} \rightarrow {D^{*}}^{+}\ell^{-}\overline{\nu}_{\ell}$ decays and obtain agreements with the Standard Model for the measured asymmetries and their differences at a $p$-value above $13\%$. From both tests, no evidence of lepton universality violation is found.
000003744 6531_ $$aSemileptonic
000003744 6531_ $$aSemileptonic B decays
000003744 6531_ $$aR(X)
000003744 6531_ $$aAngular asymmetry
000003744 6531_ $$aAfb
000003744 6531_ $$aLFV
000003744 6531_ $$aLFUV
000003744 6531_ $$aFEI
000003744 6531_ $$aR(D*)
000003744 6531_ $$aMoriond
000003744 6531_ $$aMoriondEW
000003744 6531_ $$aMoriondEWK
000003744 6531_ $$aMoriond EW
000003744 6531_ $$aMoriond EWK
000003744 6531_ $$aMoriond2023
000003744 8560_ $$fkojima@hepl.phys.nagoya-u.ac.jp
000003744 8564_ $$uhttps://docs.belle2.org/record/3744/files/BELLE2-CONF-PROC-2023-029.pdf