# Belle

The Belle detektor with open muon system
Comparison of the previous and improved full reconstruction of B mesons

## Project

The Belle detector analyzes reactions at the e+e--collider KEKB at the KEK laboratory in Tsukuba, Japan. Because the center of mass energy is equal to the mass of the Y(4S) resonance and the Y(4S) meson decays into a pair of B mesons, it is called a B factory. By using different energies for the electron and positron beams it is possible to measure the difference in the decay times of the two B mesons. With this setup, the Belle experiment could confirm CP violation in the B0 meson system which was predicted by the theory of Kobayashi and Maskawa who were awarded the Nobel prize for their theory. Furthermore, the large data sample of the Belle experiment allows to perform several high precision measurements on a broad fieled of flavor physics research. The aim of these measurements is to observe deviations from the predictions of the standard model of particle physics to obtain evidence for new particles or interactions.

## Contribution of the IEKP

The IEKP is a member of the Belle collaboration since 2008 and performs analyses of CP violation, rare decays and charm physics. Furthermore, we develop high performance analysis algorithms. We could, for example, more than double the number of fully reconstructed B mesons in the Belle dataset.

 Autor bzw. Beitrag des EKP Typ Titel Nummer und Download Prim, Michael Artikel Angular analysis of B^{0}→ϕK^{*} decays and search for CP violation at Belle Download Heller, Andreas; Feindt, Michael; Heck, Martin; Zupanc, Anze; Kuhr, Thomas; Goldenzweig, Pablo Konferenzbeitrag Messung des semileptonischen Zerfalls $B^+\rightarrow \ell^+\nu\gamma$ mit $\ell^+ = e^+, \mu^+$ Download Huschle, Matthias Interne Note Search for Charged Higgs Contribution in $B\rightarrow D^\ast\tau\nu_\tau$ Download Kronenbitter, Bastian Doktorarbeit Measurement of the branching fraction of $B^+ \to \tau^+ \nu_\tau$ decays at the Belle experiment IEKP-KA/2014-21 Grygier, Johannes Diplomarbeit Development and Evaluation of a newCalorimeter Based Variable for Missing Energy Analyses at the Belle Experiment IEKP-KA/2013-07 Prim, Michael Doktorarbeit Angular Analysis of B → φK∗ Decays and Search for CP Violation at the Belle Experiment IEKP-KA/2013-22 Rilling, Simeon Diplomarbeit Measurement of the Branching Fraction and the CP Violation of B^{+} -> \bar{D}^{0} D^{+} Decays at the Belle Experiment IEKP-KA/2013-24 Wehle, Simon Diplomarbeit Full Reconstruction of the Υ(5S) Resonance and Analysis of the Tetraquark State Z_B at Belle IEKP-KA/2013-03 Zander, Daniel Doktorarbeit Full Reconstruction And Search For Charged Higgs Effects In Semi-Tauonic B Decays IEKP-KA/2013-02 Ziegler, Michael Diplomarbeit Search for the rare decay B0 → τ+τ- at the Belle experiment IEKP-KA/2013-05