Understanding two same-sign and three leptons with $b$-jets in four top quark events at the LHC

Thuso Mathaha; Abhaya Kumar Swain; Mukesh Kumar; Xifeng Ruan; Bruce Mellado

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arXiv · 2109.06951

Understanding two same-sign and three leptons with $b$-jets in four top quark events at the LHC

Thuso Mathaha·Abhaya Kumar Swain·Mukesh Kumar·Xifeng Ruan·Bruce Mellado

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Abstract

The top quark is the heaviest known elementary particle of the Standard Model (SM) of particle physics and, therefore, it is expected to have large couplings to hypothetical new physics in many models beyond the SM (BSM). Various studies have predicted the presence of multi-lepton anomalies at the LHC. One of those anomalies is the excess production of two same-sign leptons and three isolated leptons in association with $b$-jets. These are reasonably well described by a 2HDM+$S$ model, where $S$ is a singlet scalar. Both the ATLAS and CMS experiments have reported sustained excesses in these final states. This includes corners of the phase-space where production of top quark pairs in association with a $W$ boson contributes to. Here, we investigate the production of two same-sign and three leptons from the production of four top quark final states. Our focus is on understanding the differences between the SM and BSM production mechanisms of four top quarks from $t\overline{t} A$ ($A \rightarrow t\overline{t}$) using Machine Leaning techniques with twelve discriminating kinematic variables.

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Thuso Mathaha, Abhaya Kumar Swain, Mukesh Kumar, Xifeng Ruan, Bruce Mellado. 2021-09-14. Understanding two same-sign and three leptons with $b$-jets in four top quark events at the LHC. https://arxiv.org/abs/2109.06951

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