Dortmund 2021 – wissenschaftliches Programm
T 81.8: Vortrag
Donnerstag, 18. März 2021, 17:45–18:00, Tf
Final state hadron multiplicity of charmless semileptonic B-decays at Belle — Florian Bernlochner, Jochen Dingfelder, •Alexander Ermakov, and Peter Lewis for the Belle collaboration — Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
The Belle experiment dataset with an integrated luminosity of 711 fb−1 from e+e− collisions allows the investigation of charmless semileptonic B-decays and their properties. These decays are interesting, because they give access to the modulus of the CKM-matrix element Vub, when combined with theory predictions. Inclusive and exclusive measurements of these decays yield different values of the modulus of Vub. Measurements at different experiments agree on this persistent tension at the 3σ level. A large source of systematic uncertainties for these types of decays can be related to the modeling of the final state hadron multiplicity. As the reconstruction and selection efficiencies of these decays depend upon the final state hadron multiplicity the related uncertainty can be reduced, if the analysis incorporates the final state hadron multiplicity dependency explicitly. Resonant and non-resonant signal contributions can thus be studied simultaneously. The talk describes the selection of B → Xu ℓ ν decays, the variables used for signal selection and background suppression, the different signal subsamples, the impact of incorporating the final state hadron multiplicity as an extraction variable as well as the systematic uncertainties on the determination of the branching fraction of charmless semileptonic B-decays.