Search for $B^+ \rightarrow K^+ \nu \bar{\nu}$ and other electroweak/radiative penguin processes at Belle II
| Autor: | Kurz, Simon |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Proceedings of Science / International School for Advanced Studies 398, (2021). doi:10.22323/1.398.0554 Proceedings of The European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2021)-Sissa Medialab Trieste, Italy, 2022.-ISBN-doi:10.22323/1.398.0554 Proceedings of The European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2021)-Sissa Medialab Trieste, Italy, 2022.-ISBN-doi:10.22323/1.398.0554European Physical Society conference on high energy physics 2021-Online conference, EPS-HEP 2021, Hamburg, Germany, 2021-07-26-2021-07-30 |
| DOI: | 10.3204/pubdb-2021-05651 |
| Popis: | Proceedings of The European Physical Society Conference on High Energy Physics ��� PoS(EPS-HEP2021) - Sissa Medialab Trieste, Italy, 2022. - ISBN - doi:10.22323/1.398.0554 European Physical Society conference on high energy physics 2021 - Online conference, EPS-HEP 2021, Hamburg, Germany, 26 Jul 2021 - 30 Jul 2021; Proceedings of Science / International School for Advanced Studies 398, (2021). doi:10.22323/1.398.0554 This contribution summarizes the first results from searches for electroweak and radiative penguin processes at the Belle II experiment installed at the SuperKEKB asymmetric energy electron-positron collider. The data sample considered by the analyses corresponds to an integrated luminosity of $63\,\text{fb}^{-1}$ collected at the $\Upsilon(4S)$ resonance. A brief summary of a search for $B \rightarrow X_s \gamma$ decays is given. This flavor-changing neutral-current decay is sensitive to many Standard Model extensions. An excess is clearly visible in the expected region. The second result is a study of $B^{\pm}\to K^{\pm} \ell^+ \ell^-$ decays. This analysis will provide an independent measurement to shed more light onto the recently observed deviations from the Standard Model expectations. A preliminary measurement of the $B^{\pm}\to K^{\pm} \ell^+ \ell^-$ signal yield is discussed. The main topic of this contribution is a search for the flavor-changing neutral-current decay $B \rightarrow K \nu \bar{\nu}$. A novel measurement method is developed, which exploits topological and kinematic properties of the decay that differ from both other $B$-meson decays and light-quark pair-production. This multivariate approach offers a significantly higher signal efficiency than the techniques used in previous publications. No signal is observed and an upper limit on the branching fraction of $B \rightarrow K \nu \bar{\nu}$ of $4.1\times10^{���5}$ is set at the $90\%$ confidence level. Published by SISSA, Trieste |
| Databáze: | OpenAIRE |
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