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新山 雅之 所属 京都産業大学 理学部 物理科学科 職種 教授 |
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| 発行・発表の年月 | 2022/07 |
| 形態種別 | その他 |
| 標題 | Measurements of the branching fraction, isospin asymmetry, and lepton-universality ratio in $B \to J/ψK$ decays at Belle II |
| 執筆形態 | その他 |
| 著者・共著者 | Belle II Collaboration,F. Abudinén,I. Adachi,R. Adak,K. Adamczyk,L. Aggarwal,P. Ahlburg,H. Ahmed,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,H. Bae,S. Baehr,S. Bahinipati,A. M. Bakich,P. Bambade,Sw. Banerjee,S. Bansal,M. Barrett,G. Batignani,J. Baudot,M. Bauer,A. Baur,A. Beaubien,A. Beaulieu,J. Becker,P. K. Behera,J. V. Bennett,E. Bernieri,F. U. Bernlochner,M. Bertemes,E. Bertholet,M. Be |
| 概要 | We report a study of $B \to J/\psi(\ell^{+}\ell^{-})K$ decays, where $\ell$
represents an electron or a muon, using $e^{+}e^{-}$ collisions at the $\Upsilon(4S)$ resonance. The data were collected by the Belle II experiment at the SuperKEKB asymmetric-energy collider during 2019-2021, corresponding to an integrated luminosity of $189$ fb$^{-1}$. The measured quantities are the branching fractions (${\mathcal B}$) of the decay channels $B^{+} \to J/\psi(e^{+}e^{-})K^{+}$, $B^{+} \to J/\psi(\mu^{+}\mu^{-}) K^{+}$, $B^{0} \to J/\psi(e^{+}e^{-}) K^{0}_{S}$, and $B^{0} \to J/\psi(\mu^{+}\mu^{-})K^{0}_{S}$; the lepton-flavor-dependent isospin asymmetries for the electron [$A_{I}\left(B \to J/\psi(e^{+}e^{-}) K\right)$] and muon [$A_{I}\left(B \to J/\psi(\mu^{+} \mu^{-}) K\right)$] channels; and the ratios of branching fractions between the muon and electron channels for the charged [$R_{K^{+ } }\left(J/\psi\right)$] and neutral kaon [$R_{K^{0 } }\left(J/\psi\right)$] case. The measurements are consistent with the world-average values. |
| PermalinkURL | http://arxiv.org/abs/2207.11275v1 |
| researchmap用URL | http://arxiv.org/pdf/2207.11275v1 |