Thesis BELLE2-PTHESIS-2023-007

Search for rare B to charm decays at Belle and sensitivity study for Phi3 at Belle II

Manish Kumar ; Dr. Kavita Lalwani ; Dr. Vishal Bhardwaj

MNIT Jaipur Jaipur

Abstract: The objective of this work is to search for the rare decay modes like B^{+} → D^{(∗)+}_{s}η, D^{(∗)+}_{s}K0, D^{+}η, and D^{+}K0 along with the branching fraction measurement of B^{0} → D^{0}η and ̄B^{0} → D^{0}K^{0} decay modes. To perform these studies, we used the data sample corresponding to an integrated luminosity of 711 fb^{−1} collected with the Belle detector at KEKB an asymmetric energy of e+e− collider. In the absence of any significant signal events, we provide upper limits at 90% confidence level on the branching fraction of B^{+} → D^{+}_{s}h, D^{(∗)+}_{s} h, and D^{+}h modes, where h denotes the neutral mesons (η, K0). Along with rare decay modes, we also report the improved measurement results of the color-suppressed decay modes: B(B0 → D0η) = (26.6 ± 1.2 ± 2.1) × 10−5 and B(B0 → D0K0) = (5.6 ± 0.5 ± 0.2) × 10−5. The first and second uncertainties are statistical and systematic, respectively. Along the study of rare decay modes, we also reconstructed D^{∗±}_{s} → D^{±}_{s} γ(D^{±}_{s} π0) and D^{∗±} → D^{0}π± decay modes using Phase III data. The D^{+}_{s} is reconstructed from four sub-decay modes: K0S K+, K+K−π+, φπ+, and ̄K∗0K+ while the D0 is reconstructed from three sub-decay modes: K−π+, K+K−, and π+π−. We get the clear signature of D+s and D0 mesons with 3.14 fb−1 data sample. In parallel to the analysis activities, I also contributed to the Belle II experiment, an upgrade of the Belle detector. I contributed mainly to the performance studies of Silicon Vertex Detector (SVD) from the Test Beam data and the visual inspection of the SVD 4th laye

Note: Presented on 05 12 2022
Note: PhD

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 Record created 2023-04-25, last modified 2023-04-25

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