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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 | 2024/05 |
| 形態種別 | その他 |
| 標題 | Search for the decay $B^{0}\toγγ$ using Belle and Belle II data |
| 執筆形態 | その他 |
| 著者・共著者 | Belle,Belle II Collaborations,:,I. Adachi,L. Aggarwal,H. Aihara,N. Akopov,A. Aloisio,S. Al Said,N. Althubiti,N. Anh Ky,D. M. Asner,H. Atmacan,T. Aushev,V. Aushev,M. Aversano,R. Ayad,V. Babu,H. Bae,S. Bahinipati,P. Bambade,Sw. Banerjee,S. Bansal,M. Barrett,J. Baudot,A. Baur,A. Beaubien,F. Becherer,J. Becker,K. Belous,J. V. Bennett,F. U. Bernlochner,V. Bertacchi,E. Bertholet,M. Bessner,S. Bettarini,B. Bhuyan,F. Bianchi,L. Bierwirth,T. Bilka,D. Biswas,A. Bobrov,D. Bodrov,A. Bolz,J. Borah,A. Boschet |
| 概要 | We report the result of a search for the rare decay $B^{0} \to \gamma \gamma$
using a combined dataset of $753\times10^{6}$ $B\bar{B}$ pairs collected by the Belle experiment and $387\times10^{6}$ $B\bar{B}$ pairs collected by the Belle II experiment from decays of the $\rm \Upsilon(4S)$ resonance produced in $e^{+}e^{-}$ collisions. A simultaneous fit to the Belle and Belle II data sets yields $11.0^{+6.5}_{-5.5}$ signal events, corresponding to a 2.5$\sigma$ significance. We determine the branching fraction $\mathcal{B}(B^{0} \to \gamma\gamma) = (3.7^{+2.2}_{-1.8}(\rm stat)\pm0.5(\rm syst))\times10^{-8}$ and set a 90% credibility level upper limit of $\mathcal{B}(B^{0} \to \gamma\gamma) < 6.4\times10^{-8}$. |
| PermalinkURL | http://arxiv.org/abs/2405.19734v1 |
| researchmap用URL | http://arxiv.org/pdf/2405.19734v1 |