|
新山 雅之 所属 京都産業大学 理学部 物理科学科 職種 教授 |
|
| 発行・発表の年月 | 2021/04 |
| 形態種別 | その他 |
| 標題 | Measurement of the branching fractions of $B\toη' K$ decays using 2019/2020 Belle II data |
| 執筆形態 | その他 |
| 著者・共著者 | Belle II Collaboration,F. Abudinén,I. Adachi,R. Adak,K. Adamczyk,P. Ahlburg,J. K. Ahn,H. Aihara,N. Akopov,A. Aloisio,F. Ameli,L. Andricek,N. Anh Ky,D. M. Asner,H. Atmacan,V. Aulchenko,T. Aushev,V. Aushev,T. Aziz,V. Babu,S. Bacher,S. Baehr,S. Bahinipati,A. M. Bakich,P. Bambade,Sw. Banerjee,S. Bansal,M. Barrett,G. Batignani,J. Baudot,A. Beaulieu,J. Becker,P. K. Behera,M. Bender,J. V. Bennett,E. Bernieri,F. U. Bernlochner,M. Bertemes,E. Bertholet,M. Bessner,S. Bettarini,V. Bhardwaj,B. Bhuyan,F. Bia |
| 概要 | This note describes the rediscovery of $B\to\eta' K$ decays in Belle II data,
both in the charged and neutral final state: $B_0\to\eta' K_S$ and $B^\pm\to\eta' K^\pm$. The $\eta'$ is searched for in two decay modes: $\eta'\to\eta\pi^+\pi^-$ with $\eta\to\gamma\gamma$, and $\eta'\to\rho\gamma$. The analysis uses data collected in 2019 and 2020 at the SuperKEKB asymmetric $e^+e^-$ collider, with an integrated luminosity of $62.8~fb^{-1}$, corresponding to $68.2$ million of $B\bar{B}$ pairs produced. The signal yield is obtained via an unbinned maximum likelihood fit to signal sensitive variables, obtaining branching ratios: $$\mathcal{B}\left(B^\pm\to\eta'K^\pm\right) = \left(63.4~^{+3.4}_{-3.3}\,(stat)\,\pm3.2\,(syst)\,\right) \times10^{-6} $$ $$\mathcal{B}\left(B_0\to\eta'K_S\right) = \left(59.9~^{+5.8}_{-5.5}\,(stat)\,\pm2.9\,(syst)\,\right) \times10^{-6} $$ which are consistent with world average. |
| PermalinkURL | http://arxiv.org/abs/2104.06224v3 |
| researchmap用URL | http://arxiv.org/pdf/2104.06224v3 |