arXiv 2101.052862021-01hep-phhep-ex

LHC及以后单顶双轻子和三轻子事件中的新味物理

New flavor physics in di- and tri-lepton events from single-top at the LHC and beyond

Yoav Afik, Shaouly Bar-Shalom, Amarjit Soni, Jose Wudka

备注：: 26 pages, 10 figures, 11 tables. Final version as published in PRD
发表信息：: Phys. Rev. D 103, 075031 (2021)
DOI：: 10.1103/PhysRevD.103.075031

摘要：

在顶衰变之后，伴随产生的单顶反号同味（OSSF）双轻子，$pp \to t \ell^+ \ell^-$和$ pp \to t \ell^+ \ell^- + j$（$j=$光喷流），可以在大型强子对撞机上引起引人注目的三轻子$pp \to \ell^\prime \ell^+ \ell^- + X$和双轻子$pp \to \ell^+ \ell^- + j_b + X$（$j_b=b$ -喷流）事件。虽然这些相当通用的多轻子信号是味盲的，它们可以产生新的4-费米味变化（FC）$u_i t \ell \ell$标量，矢量和张量相互作用（$u_i \in u,c$），我们在本文中研究，我们匹配的FC $u_i t \ell \ell$ 4-费米条款的SMEFT运营商，也到不同类型的FC基础重物理。这些二轻子和三轻子信号的主要背景来自于$t \bar t$、$Z$ +喷流和$VV$（$V=W,Z$）的产生，但它们可以通过对OSSF双轻子$m_{\ell^+ \ell^-}^{\tt min}(OSSF) > 1$ TeV的足够高的不变质量选择而基本消除;在双轻子末态情况下使用$b$标记作为额外的选择也被证明是非常有用的。我们发现，例如，预期的95\% CL范围内的张量（矢量）$u t μμ$相互作用的规模，与当前的$\sim 140$ FB $^{-1}$的大型强子对撞机数据，是$Λ< 5(3.2) $ TeV或$Λ< 4.1(2.7)$ TeV，如果通过二μ子$μ^+ μ^- + j_b$信号或$e μ^+ μ^-$三轻子之一，分别进行分析。在HL-LHC上，3000 fb $^{-1}$数据的预期范围是$Λ< 7.1(4.7)$ TeV和$Λ< 2.4(1.5)$ TeV，对应的$u t μμ$和$c t μμ$算子。我们还研究了潜在的灵敏度在未来的27 TeV和100 TeV的高能LHC的继任者，也讨论了可能的影响，这类FC 4费米有效的相互作用轻子非普适性测试在LHC。

英文摘要：

The associated production of a single-top with opposite-sign same-flavor (OSSF) di-leptons, $pp \to t \ell^+ \ell^-$ and $ pp \to t \ell^+ \ell^- + j$ ($j=$light jet), can lead to striking tri-lepton $pp \to \ell^\prime \ell^+ \ell^- + X$ and di-lepton $pp \to \ell^+ \ell^- + j_b + X$ ($j_b=b$-jet) events at the LHC, after the top decays. Although these rather generic multi-lepton signals are flavor-blind, they can be generated by new 4-Fermi flavor changing (FC) $u_i t \ell \ell$ scalar, vector and tensor interactions ($u_i \in u,c$), which we study in this paper; we match the FC $u_i t \ell \ell$ 4-Fermi terms to the SMEFT operators and also to different types of FC underlying heavy physics. The main backgrounds to these di- and tri-lepton signals arise from $t \bar t$, $Z$+jets and $VV$ ($V=W,Z$) production, but they can be essentially eliminated with a sufficiently high invariant mass selection on the OSSF di-leptons, $m_{\ell^+ \ell^-}^{\tt min}(OSSF) > 1$ TeV; the use of $b$-tagging as an additional selection in the di-lepton final state case also proves very useful. We find, for example, that the expected 95\% CL bounds on the scale of a tensor(vector) $u t μμ$ interaction, with the current $\sim 140$ fb$^{-1}$ of LHC data, are $Λ< 5(3.2) $ TeV or $Λ< 4.1(2.7)$ TeV, if analyzed via the di-muon $μ^+ μ^- + j_b$ signal or the $e μ^+ μ^-$ tri-lepton one, respectively. The expected reach at the HL-LHC with 3000 fb$^{-1}$ of data is $Λ< 7.1(4.7)$ TeV and $Λ< 2.4(1.5)$ TeV for the corresponding $u t μμ$ and $c t μμ$ operators. We also study the potential sensitivity at future 27 TeV and 100 TeV high-energy LHC successors and also discuss the possible implications of this class of FC 4-Fermi effective interactions on lepton non-universality tests at the LHC.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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英文摘要：

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