"Acceptance $\times$ Efficiency ZPhiPS ele" of "Search for a scalar or pseudoscalar dilepton resonance produced in association with a massive vector boson or top quark-antiquark pair in multilepton events at $\sqrt{s}$ = 13 TeV"

A search for beyond the standard model spin-0 bosons, $\phi$, that decay into pairs of electrons, muons, or tau leptons is presented. The search targets the associated production of such bosons with a $\mathrm{W}$ boson, a $\mathrm{Z}$ boson, or a top quark-antiquark pair, and uses events with three or four charged leptons, including hadronically decaying tau leptons. The proton-proton collision dataset used in the analysis was collected by the CMS experiment at the LHC in 2016-2018 at a center-of-mass energy of $13\,\mathrm{TeV}$, and corresponds to an integrated luminosity of $138\,\mathrm{fb}^{-1}$. The observations are consistent with the expectations from standard model processes. Upper limits at $95\%$ confidence level are placed on the product of the cross sections and branching fractions of such new particles with scalar, pseudoscalar, or Higgs-like couplings, as well as the product of coupling parameters and branching fractions. These are the most restrictive direct limits in these production and decay modes on an extension of the standard model with scalar or pseudoscalar particles. Several model-dependent exclusions are also presented. For a Higgs-like $\phi$ model, limits are set on the mixing angle of the Higgs boson with the $\phi$ boson. For the associated production of a $\phi$ boson with a top quark-antiquark pair, limits are set on the coupling to top quarks. Finally, limits are set for the first time on a fermiophilic dilaton-like model with scalar couplings and an axion-like model with pseudoscalar couplings.

本研究开展了一项针对衰变至电子、μ子或τ轻子对的超越标准模型（beyond the standard model）自旋0玻色子φ的搜寻工作。该搜寻针对此类玻色子与W玻色子、Z玻色子或顶夸克-反夸克对的联合产生过程，选取包含强子化衰变τ轻子的三或四带电轻子事例作为分析对象。分析所使用的质子-质子碰撞数据集由大型强子对撞机（Large Hadron Collider, LHC）上的CMS（Compact Muon Solenoid）实验于2016至2018年间采集，质心系能量为13 TeV，对应积分亮度为138 fb⁻¹。观测结果与标准模型过程的理论预期相符。本分析对这类具有标量、赝标量或类希格斯耦合的新粒子的截面与分支比乘积，以及耦合参数与分支比的乘积设置了95%置信水平的上限。这是此类产生与衰变模式下，针对含标量或赝标量粒子的标准模型扩充理论最严苛的直接限制。本文同时给出了若干依赖模型的排除结果。针对类希格斯φ模型，我们设置了希格斯玻色子与φ玻色子的混合角限制。针对φ玻色子与顶夸克-反夸克对的联合产生过程，我们设置了其与顶夸克的耦合参数限制。最后，我们首次为具有标量耦合的费米亲和类胀子（dilaton）模型以及具有赝标量耦合的类轴子模型设置了实验限制。