论文标题
搜索全部夸克的标量合作伙伴，在全部夸克$ t \ bar {t} $加上$ \ sqrt {s} = 13 $ tev的缺失的横向动量最终状态与Atlas detector
Search for a scalar partner of the top quark in the all-hadronic $t\bar{t}$ plus missing transverse momentum final state at $\sqrt{s}=13$ TeV with the ATLAS detector
论文作者
论文摘要
搜索在全部hadronic $ t \ bar {t} $加上缺失的横向动量最终状态中，搜索了顶级夸克（顶部quark或标量第三代leptoquarks）的标量合作伙伴。 $ {\ sqrt {s} = 13}的139 fb $^{ - 1} $的分析$ tev Proton-proton碰撞数据使用ATLAS检测器在LHC上收集，与标准模型背景预期相比，无显着多余。为了解释结果，使用了一个超对称模型，其中最高的斜视通过$ \ tilde {t} \ to t^{（*）} \tildeχ^0_1 $，带有$ t^{（*）} $表示shell（off-shell（off-shell（off-shell）top Quark）和$ \ tilde的uilde pilteuc^0_1 $ neuttim neuntino。针对以下方案进行了优化的三个特定事件选择。在情况下，其中$ m _ {\ tilde {t}}> m_t+m _ {\tildeχ^0_1} $，在400-1250 GEV中排除了$ \tildeχ^0_1 $低于95％$ 200 $ GEV的范围400-1250 GEV。在这种情况下，$ m _ {\ tilde {t}} \ sim m_t+m _ {\tildeχ^0_1} $，排除了300-630 GEV范围内的高层大量质量，而在$ m _ {\ m_ {\ tilde {\ tilde {tilde {t}} <m_w+m_w+m_b+m_b+m_b+m_b+m___ （使用$ M _ {\ tilde {t}} - m _ {\tildeχ^0_1} \ ge 5 $ GEV，首次在ATLAS全hadronic搜索中首次考虑，范围300-660 GEV的Top Squark Masses被排除在外。标量第三代上型Leptoquarks也设定了限制，当时仅考虑Leptoquark腐烂到顶级夸克和中微子，不包括低于$ 1240 $ GEV的Leptoquarks。
A search for direct pair production of scalar partners of the top quark (top squarks or scalar third-generation up-type leptoquarks) in the all-hadronic $t\bar{t}$ plus missing transverse momentum final state is presented. The analysis of 139 fb$^{-1}$ of ${\sqrt{s}=13}$ TeV proton-proton collision data collected using the ATLAS detector at the LHC yields no significant excess over the Standard Model background expectation. To interpret the results, a supersymmetric model is used where the top squark decays via $\tilde{t} \to t^{(*)} \tildeχ^0_1$, with $t^{(*)}$ denoting an on-shell (off-shell) top quark and $\tildeχ^0_1$ the lightest neutralino. Three specific event selections are optimised for the following scenarios. In the scenario where $m_{\tilde{t}}> m_t+m_{\tildeχ^0_1}$, top squark masses are excluded in the range 400-1250 GeV for $\tildeχ^0_1$ masses below $200$ GeV at 95 % confidence level. In the situation where $m_{\tilde{t}}\sim m_t+m_{\tildeχ^0_1}$, top squark masses in the range 300-630 GeV are excluded, while in the case where $m_{\tilde{t}}< m_W+m_b+m_{\tildeχ^0_1}$ (with $m_{\tilde{t}}-m_{\tildeχ^0_1}\ge 5$ GeV), considered for the first time in an ATLAS all-hadronic search, top squark masses in the range 300-660 GeV are excluded. Limits are also set for scalar third-generation up-type leptoquarks, excluding leptoquarks with masses below $1240$ GeV when considering only leptoquark decays into a top quark and a neutrino.
