https://scholars.lib.ntu.edu.tw/handle/123456789/606629
標題: | Test of lepton flavor universality and search for lepton flavor violation in B → K?? decays | 作者: | PAO-TI CHANG et al. WEI-SHU HOU et al. |
關鍵字: | B physics; e+-e? Experiments; FCNC Interaction; Flavor physics; Flavour Changing Neutral Currents; | 公開日期: | 2021 | 卷: | 2021 | 期: | 3 | 來源出版物: | Journal of High Energy Physics | 摘要: | We present measurements of the branching fractions for the decays B → Kμ+μ? and B → Ke+e?, and their ratio (RK), using a data sample of 711 fb?1 that contains 772 × 106BB¯ events. The data were collected at the ?(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e? collider. The ratio RK is measured in five bins of dilepton invariant-mass-squared (q2): q2 ? (0.1, 4.0), (4.00, 8.12), (1.0, 6.0), (10.2, 12.8) and (> 14.18) GeV2/c4, along with the whole q2 region. The RK value for q2 ? (1.0, 6.0) GeV2/c4 is 1.03?0.24+0.28 ± 0.01. The first and second uncertainties listed are statistical and systematic, respectively. All results for RK are consistent with Standard Model predictions. We also measure CP-averaged isospin asymmetries in the same q2 bins. The results are consistent with a null asymmetry, with the largest difference of 2.6 standard deviations occurring for the q2 ? (1.0, 6.0) GeV2/c4 bin in the mode with muon final states. The measured differential branching fractions, d? /dq2, are consistent with theoretical predictions for charged B decays, while the corresponding values are below the expectations for neutral B decays. We have also searched for lepton-flavor-violating B → Kμ±e? decays and set 90% confidence-level upper limits on the branching fraction in the range of 10?8 for B+ → K+μ±e?, and B0 → K0μ±e? modes. [Figure not available: see fulltext.] ? 2021, The Author(s). |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102586238&doi=10.1007%2fJHEP03%282021%29105&partnerID=40&md5=48a72dbc64cf581ebc5411ff85612d21 https://scholars.lib.ntu.edu.tw/handle/123456789/606629 |
ISSN: | 10298479 | DOI: | 10.1007/JHEP03(2021)105 |
顯示於: | 物理學系 |
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