论文标题
B $^0_ \ Mathrm {s} $ $ cp $ - 略列$ ϕ_ \ mathrm {s} $的测量值TEV
Measurement of the $CP$-violating phase $ϕ_\mathrm{s}$ in the B$^0_\mathrm{s}$ $\to$ J$/ψ\, ϕ$(1020) $\to$ $μ^+μ^-$K$^+$K$^-$ channel in proton-proton collisions at $\sqrt{s} =$ 13 TeV
论文作者
论文摘要
$ cp $ - 抗弱相$ ϕ_ \ mathrm {s} $和衰减宽度差异$Δγ_\ Mathrm {s} $在轻度和重型b $^0_ \ mathrm {s} $ s} $ gose eigenstate的cms eigenstate中的cms检测器中的cms eigenstates均在48 500 500 $ a的样品中测量。 $ \ to $ j $/ψ\，ϕ $（1020）$ \ to $ $μ^+μ^ - $ k $^+$ k $^ - $ evest。该测量基于对应于96.4 fb $^{ - 1} $的集成光度的数据样本，该数据样本在$ \ sqrt {s} = $ 13 TEV中收集在2017- 2018年的质子 - 普罗顿碰撞中。提取$ ϕ_ \ mathrm {s} $和$δγ_\ mathrm {s} $的值，对$μ^+μ^ - $ k $^+$ k $^$ k $^ - $最终状态进行了$μ^+μ^ - $ k $^+$ k $^ - $最终状态。该分析采用了专用的标记扳机和基于机器学习技术的新型相反的MUON风味标记。 The measurement yields $ϕ_\mathrm{s} = -$11 $\pm$ 50 (stat) $\pm$ 10 (syst) mrad and $ΔΓ_\mathrm{s} =$ 0.114 $\pm$ 0.014 (stat) $\pm$ 0.007 (syst) ps$^{-1}$, in agreement with the standard model predictions. When combined with the previous CMS measurement at $\sqrt{s} =$ 8 TeV, the following values are obtained: $ϕ_\mathrm{s} = -$21 $\pm$ 44 (stat) $\pm$ 10 (syst) mrad, $ΔΓ_\mathrm{s} =$ 0.1032 $\pm$ 0.0095 (stat) $\pm$ 0.0048（SYST）PS $^{ - 1} $，比8 TEV结果的显着改善。
The $CP$-violating weak phase $ϕ_\mathrm{s}$ and the decay width difference $ΔΓ_\mathrm{s}$ between the light and heavy B$^0_\mathrm{s}$ mass eigenstates are measured with the CMS detector at the LHC in a sample of 48 500 reconstructed B$^0_\mathrm{s}$ $\to$ J$/ψ\, ϕ$(1020) $\to$ $μ^+μ^-$K$^+$K$^-$ events. The measurement is based on a data sample corresponding to an integrated luminosity of 96.4 fb$^{-1}$, collected in proton-proton collisions at $\sqrt{s} =$ 13 TeV in 2017-2018. To extract the values of $ϕ_\mathrm{s}$ and $ΔΓ_\mathrm{s}$, a time-dependent and flavor-tagged angular analysis of the $μ^+μ^-$K$^+$K$^-$ final state is performed. The analysis employs a dedicated tagging trigger and a novel opposite-side muon flavor tagger based on machine learning techniques. The measurement yields $ϕ_\mathrm{s} = -$11 $\pm$ 50 (stat) $\pm$ 10 (syst) mrad and $ΔΓ_\mathrm{s} =$ 0.114 $\pm$ 0.014 (stat) $\pm$ 0.007 (syst) ps$^{-1}$, in agreement with the standard model predictions. When combined with the previous CMS measurement at $\sqrt{s} =$ 8 TeV, the following values are obtained: $ϕ_\mathrm{s} = -$21 $\pm$ 44 (stat) $\pm$ 10 (syst) mrad, $ΔΓ_\mathrm{s} =$ 0.1032 $\pm$ 0.0095 (stat) $\pm$ 0.0048 (syst) ps$^{-1}$, a significant improvement over the 8 TeV result.
