000002532 001__ 2532
000002532 005__ 20220328134909.0
000002532 037__ $$aBELLE2-MTHESIS-2021-069
000002532 041__ $$aeng
000002532 100__ $$aKilian Lieret
000002532 245__ $$aConstruction of Angular Observables Sensitive to New Physics in $\bar B\to D^*\tau^-\bar \nu_\tau$ Decays and Measurements of Differential Cross Sections of $\bar B\to D^*\ell^-\bar\nu_\ell$ Decays with Hadronic Tagging at Belle
000002532 260__ $$aMunich$$bLudwig Maximilian University of Munich$$c2018
000002532 300__ $$a183
000002532 500__ $$aPresented on 16 09 2018
000002532 502__ $$aMSc$$bMunich, Ludwig Maximilian University of Munich$$c2018
000002532 520__ $$aRecent measurements of $\bar B\to D^{(*)}\ell^-\bar\nu_\ell$ cross sections at Belle, BaBar, and LHCb challenge lepton universality and thus the Standard Model at a combined confidence level close to four standard deviations. New measurements of differential decay rates could contribute to the understanding of these anomalies. The differential cross section of the decay $\bar{B} \longrightarrow D^{*}(\rightarrow D \pi) l^{-} \bar{\nu}_{l}$ is parametrized according to different dependencies on the three decay angles and the coupling constants of potential new physics contributions. Observables using binned measurements of the differential cross section are characterized and explicitly constructed. Based on an estimate for the obtainable sensitivity, optimal binnings for such measurements are discussed. The discriminatory power of the thus constructed observables is discussed based on a basis of dimension six operators with renormalizable couplings contributing to $\bar{B} \longrightarrow D^{*} l^{-} \bar{\nu}_{l}$. Furthermore, continuing work on an analysis of the $\bar{B} \longrightarrow D^{*}(\rightarrow D \pi) \ell^{-} \bar{\nu}_{\ell}$ decay channel for $\ell=e, \mu$ using data from the Belle detector at KEKB is presented. The events are selected from 772 million $e^{+} e^{-} \rightarrow \Upsilon(4 S) \rightarrow B \bar{B}$ events, where one $B$ meson is fully reconstructed in hadronic modes. Unfolded differential decay rates in four kinematic variables are presented separately for $\ell=e, \ell=\mu$ and a combined fit, allowing for precise calculations of $V_{c b}$ and $B \longrightarrow D^{*}$ form factors. The new lepton flavor specific results are also expected to impact the discussion about potential light lepton flavor universality violations prompted by measurements of $B \longrightarrow K^{(*)} \ell \ell$ decays.
000002532 700__ $$aThomas Kuhr$$edir.
000002532 700__ $$aMartin Jung$$edir.
000002532 700__ $$aGerhard Buchalla$$edir.
000002532 8560_ $$fkilian.lieret@campus.lmu.de
000002532 8564_ $$uhttps://docs.belle2.org/record/2532/files/thesis.pdf$$yThesis
000002532 980__ $$aTHESIS