"Table 3" of "Search for heavy particles decaying into a top-quark pair in the fully hadronic final state in $pp$ collisions at $\sqrt{s} =13$ TeV with the ATLAS detector"

A search for new particles decaying into a pair of top quarks is performed using proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at a center-of-mass energy of $\sqrt{s}$ = 13 TeV corresponding to an integrated luminosity of 36.1 fb$^{-1}$. Events consistent with top-quark pair production and the fully hadronic decay mode of the top quarks are selected by requiring multiple high transverse momentum jets including those containing b-hadrons. Two analysis techniques, exploiting dedicated top-quark pair reconstruction in different kinematic regimes, are used to optimize the search sensitivity to new hypothetical particles over a wide mass range. The invariant mass distribution of the two reconstructed top-quark candidates is examined for resonant production of new particles with various spins and decay widths. No significant deviation from the Standard Model prediction is observed and limits are set on the production cross-section times branching fraction for new hypothetical $Z^{\prime}$ bosons, dark-matter mediators, Kaluza-Klein gravitons and Kaluza-Klein gluons. By comparing with the predicted production cross-sections, the $Z^{\prime}$ boson in the topcolor-assisted-technicolor model is excluded for masses up to 3.1−3.6 TeV, the dark-matter mediators in a simplified framework are excluded in the mass ranges from 0.8 TeV to 0.9 TeV and from 2.0 TeV to 2.2 TeV, and the Kaluza-Klein gluon is excluded for masses up to 3.4 TeV, depending on the decay widths of the particles.本研究针对衰变至顶夸克（top quark）对的新粒子开展搜寻，分析了大型强子对撞机（Large Hadron Collider）上ATLAS探测器（ATLAS）采集的、质心系能量√s=13 TeV、积分亮度为36.1 fb⁻¹的质子-质子碰撞数据。通过筛选多个高横动量喷注（其中包含含b强子的喷注），选取符合顶夸克对产生过程以及顶夸克全强子衰变模式的物理事例。本研究采用两种分析方法，分别针对不同运动学区域开展专属的顶夸克对重建工作，以优化对宽质量范围内假想新粒子的搜寻灵敏度。对两个重建顶夸克候选体的不变质量分布展开分析，以搜寻不同自旋与衰变宽度的新粒子共振产生信号。本次分析未观测到与标准模型（Standard Model）预言存在显著偏离的信号，并对假想的Z'玻色子（Z' boson）、暗物质媒介子（dark-matter mediator）、卡鲁扎-克莱因引力子（Kaluza-Klein graviton）以及卡鲁扎-克莱因胶子（Kaluza-Klein gluon）的产生截面与分支比的乘积设置了排除上限。通过与理论预言的产生截面对比，顶色辅助色超导模型中的Z'玻色子在质量不超过3.1~3.6 TeV的区间被排除；简化框架下的暗物质媒介子在0.8 TeV至0.9 TeV以及2.0 TeV至2.2 TeV的质量区间被排除；而卡鲁扎-克莱因胶子则在依赖其自身衰变宽度的前提下，质量不超过3.4 TeV的区间被排除。