"Table 52" of "Search for dark matter produced in association with bottom or top quarks in $\sqrt{s}$ = 13 TeV pp collisions with the ATLAS detector"

A search for weakly-interacting-massive-particle (WIMP) dark matter produced in association with bottom or top quarks is presented. Final states containing third generation quarks and missing transverse momentum are considered. The analysis uses 36.1 fb-1 of proton-proton collisions data recorded by the ATLAS experiment at sqrt(s)=13 TeV in 2015 and 2016. No significant deviation from the background prediction is observed. The results are interpreted in the framework of simplified models of spin-0 dark matter mediators. For colour-neutral spin-0 mediators decaying into a pair of dark matter particles, signals with scalar mediator masses below 50 GeV in top quark final states are excluded, assuming a dark matter mass of 1 GeV and unitary coupling. For bottom quark final states 300 times the value of the production cross section for signals with scalar and pseudoscalar mediator masses between 10 and 50 GeV are excluded, assuming a dark matter mass of 1 GeV and unitary coupling. Constraints on colour-charged scalar simplified models are also presented. Assuming a dark matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding to a dark matter relic density consistent with measurements.

本文报道一项针对伴随底夸克或顶夸克产生的弱相互作用大质量粒子（Weakly-interacting-massive-particle, WIMP）暗物质的搜寻分析。分析考虑了包含第三代夸克与缺失横向动量的末态。本分析使用了ATLAS实验在2015年与2016年采集的、质心系能量√s=13 TeV的36.1 fb⁻¹质子-质子对撞数据。未观测到与本底预期存在显著偏差的信号。研究结果基于自旋0暗物质媒介子简化模型的框架进行阐释。对于衰变至一对暗物质粒子的色中性自旋0媒介子，在暗物质质量为1 GeV且耦合为幺正耦合的假设下，顶夸克末态中标量媒介子质量低于50 GeV的信号被排除。对于底夸克末态，在暗物质质量为1 GeV且耦合为幺正耦合的假设下，媒介子质量介于10 GeV至50 GeV之间的标量与赝标量信号，其产生截面的300倍上限被排除。本文还给出了带色标量简化模型的实验约束。在暗物质粒子质量为35 GeV的假设下，对于暗物质遗留丰度与实验测量结果相符的耦合情形，质量低于1.1 TeV的媒介子被排除。