论文标题
通过$ z $相关的顶级对SMEFT的顶级电动扇区限制HL-LHC的单个顶级生产
Constraining the top electroweak sector of the SMEFT through $Z$ associated top pair and single top production at the HL-LHC
论文作者
论文摘要
我们在标准模型有效现场理论(SMEFT)的框架中研究了$ pp \ to t \ bar {t} z $和$ pp \ to tzj $,采用常规的剪切计数以及机器学习技术来利用涉及多个leptons和$ b $ $ $ jets的复杂最终状态中的运动信息。我们探索了两个SMEFT运算符的预计灵敏度,$ \ Mathcal {o} _ {tz} $和$ \ Mathcal {O} _ {tw} $,通过在HL-LHC上的这些电子顶生产过程中的直接搜索来诱导Electroweak Dipole Moment互动。还考虑了对主要背景的新物理修饰。我们表明,可以通过相关运动学可观察力和机器学习技术的差分分布的组合来增强新的物理敏感性。 $ t \ bar {t} z $和$ tzj $生产中的搜索对$ \ Mathcal {c} _ {tz} $和$ \ MATHCAL {C} _ {TW} $的限制更强。在HL-LHC上,$ \ MATHCAL {C} _ {tz} $可以通过在$ pp \ to t \ bar {t \ bar {t} z + clinder + clull + clinder geq + ender clinder中搜索,可探测高达$ -0.41 \ liseSim \ lisssim \ liseSim \ Mathcal {c} _ {tz} \ lyssim 0.47 $ $ \ MATHCAL {C} _ {TW} $可以探索$ -0.14 \ LISSSIM \ MATHCAL {C} _ {C} _ {TW} <0.11 $,从$ pp \ to pp \ to tzj + t \ t \ b bar {t} z + twz z + twz \ 3 \ ell + 1b + 1b + 1b + 1 $ 1/2j的搜索中的搜索中。
We study the processes $pp \to t\bar{t}Z$ and $pp \to tZj$ in the framework of Standard Model Effective Field Theory (SMEFT), employing conventional cut-and-count as well as machine learning techniques to take advantage of kinematic information in complex final states involving multiple leptons and $b$ jets. We explore the projected sensitivity for two SMEFT operators, $\mathcal{O}_{tZ}$ and $\mathcal{O}_{tW}$, that induce electroweak dipole moment interactions for top quarks, through direct searches in these electroweak top production processes at the HL-LHC. New physics modifications to dominant backgrounds are also considered. We show that the new physics sensitivity can be enhanced through a combination of differential distributions for relevant kinematic observables and machine learning techniques. Searches in $t\bar{t}Z$ and $tZj$ production result in stronger constraints on $\mathcal{C}_{tZ}$ and $\mathcal{C}_{tW}$, respectively. At the HL-LHC, $\mathcal{C}_{tZ}$ can be probed up to $-0.41 \lesssim \mathcal{C}_{tZ} \lesssim 0.47$ through searches in the $pp \to t\bar{t}Z + tWZ \to 3\ell + 2b\ + \geq 2j$ channel while $\mathcal{C}_{tW}$ can be probed up to $-0.14 \lesssim \mathcal{C}_{tW} < 0.11$ from searches in the $pp \to tZj + t\bar{t}Z + tWZ \to 3\ell + 1b + 1/2j$ channel, at $95\%$ CL.