000003644 001__ 3644
000003644 005__ 20230614085357.0
000003644 037__ $$aBELLE2-MTHESIS-2023-032
000003644 041__ $$aeng
000003644 100__ $$aSofia Palacios Schweitzer
000003644 245__ $$aInclusive B-Meson Tagging for an R(D*) Measurement at Belle II
000003644 260__ $$aMunich$$bLMU$$c2022
000003644 300__ $$a71
000003644 500__ $$aPresented on 13 09 2022
000003644 502__ $$aMSc$$bMunich, LMU$$c2022
000003644 520__ $$aThe world average of previous R(D(*)) measurements, defined as R(D(*)) = BR(B -> D(*) tau nu) / BR(B -> D(*) l nu) with l = e, mu, shows a 3.3 sigma deviation from Standard Model predictions, which could indicate some New Physics phenomenon, such as the existence of Leptoquarks. This analysis uses simulations from the Belle II experiment at the SuperKEKB electron-positron collider to measure R(D*). To account for the challenge of multiple neutrinos as final state particles, an approach is considered, where besides the signal B-meson decay kinematical and topological properties of the other B-meson are reconstructed fully inclusively. In contrast to an exclusive reconstruction of the second B-meson used for previous R(D*) measurements by the B-factories, this inclusive approach suffers from a larger background, but also offers a higher reconstruction efficiency. As part of the analysis machine learning methods are studied to suppress different background sources. R(D*) is extracted from a two-dimensional extended maximum likelihood fit.
000003644 700__ $$aThomas Kuhr$$edir.
000003644 700__ $$aThomas Lueck$$edir.
000003644 8560_ $$fthomas.kuhr@lmu.de
000003644 8564_ $$uhttps://docs.belle2.org/record/3644/files/BELLE2-MTHESIS-2023-032.pdf
000003644 980__ $$aTHESIS