Results on [Formula: see text] decays with the CMS experiment are reported, using 61 fb[Formula: see text] of data recorded during LHC Run 1 and 2016. With an improved muon identification algorithm and refined unbinned maximum likelihood fitting methods, the decay [Formula: see text] is observed with a significance of 5.6 standard deviations. Its branching fraction is measured to be [Formula: see text], where the first error is the combined statistical and systematic uncertainty and the second error quantifies the uncertainty of the [Formula: see text] and [Formula: see text] fragmentation probability ratio. The [Formula: see text] effective lifetime is [Formula: see text]. No evidence for the decay [Formula: see text] is found and an upper limit of [Formula: see text] (at 95% confidence level) is determined. All results are consistent with the standard model of particle physics.

中文翻译：

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B → μ+μ− 的最新结果随着 CMS 实验而衰减

使用 LHC 第 1 次和 2016 年期间记录的 61 fb[公式：见文本] 数据报告了 CMS 实验中 [公式：见文本] 衰减的结果。通过改进的 μ 子识别算法和改进的未合并最大似然拟合方法，衰减 [公式：见正文] 的显着性为 5.6 个标准差。其支化分数被测量为[公式：见正文]，其中第一个误差是组合的统计和系统不确定性，第二个误差量化了[公式：见正文]和[公式：见正文]碎片概率比的不确定性. [公式：见正文] 有效寿命为 [公式：见正文]。没有发现衰减[公式：见文本]的证据，并确定了[公式：见文本]的上限（95% 置信水平）。