论文标题
$ \ sqrt {s} = $ 13 tev
Inclusive nonresonant multilepton probes of new phenomena at $\sqrt{s} =$ 13 TeV
论文作者
论文摘要
提出了对三个或更多带电瘦素的事件中的超出标准模型（SM）现象的非共振签名的包容性搜索，包括强调衰减的$τ$ leptons。该分析基于一个数据样本，该数据样本对应于proton-proton碰撞的138 fb $^{ - 1} $的$ \ sqrt {s} = $ 13 TEV，该proton-proton碰撞，由CMS实验收集，于2016- 2018年在LHC上收集。事件根据Lepton和B标签的JET多重性和各种运动学变量进行分类。探测了SM以外的物理学的三种情况，并使用信号特定的推动决策树来增强灵敏度。没有观察到与背景期望的显着偏差。对于III III型seesaw重型费米子的质量为845-1065 GEV的质量为95％的置信水平，用于与Sm瘦素的各种衰减分支分数组合。 SM的Doublet和Singlet矢量样$τ$ Lepton扩展分别排除在1045 GEV和质量范围125-150 GEV中。根据Lepton的味道，排除在1.12-1.42 TEV以下的标量leptoquarks腐烂，排在1.12-1.42以下。对于III类型Seesaw以及类似向量的双重模型，这些约束是迄今为止最严格的。对于类似矢量的单元模型，这些是LHC实验的第一个约束。还提出了详细的结果，以促进替代理论解释。
An inclusive search for nonresonant signatures of beyond the standard model (SM) phenomena in events with three or more charged leptons, including hadronically decaying $τ$ leptons, is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 138 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} =$ 13 TeV, collected by the CMS experiment at the LHC in 2016-2018. Events are categorized based on the lepton and b-tagged jet multiplicities and various kinematic variables. Three scenarios of physics beyond the SM are probed, and signal-specific boosted decision trees are used for enhancing sensitivity. No significant deviations from the background expectations are observed. Lower limits are set at 95% confidence level on the mass of type-III seesaw heavy fermions in the range 845-1065 GeV for various decay branching fraction combinations to SM leptons. Doublet and singlet vector-like $τ$ lepton extensions of the SM are excluded for masses below 1045 GeV and in the mass range 125-150 GeV, respectively. Scalar leptoquarks decaying exclusively to a top quark and a lepton are excluded below 1.12-1.42 TeV, depending on the lepton flavor. For the type-III seesaw as well as the vector-like doublet model, these constraints are the most stringent to date. For the vector-like singlet model, these are the first constraints from the LHC experiments. Detailed results are also presented to facilitate alternative theoretical interpretations.
