Search for long-lived particles decaying to leptons with large impact parameter in proton–proton collisions at $$\sqrt{s} = 13\,\text {Te}\text {V}$$

Abstract

A search for new long-lived particles decaying to leptons using proton–proton collision data produced by the CERN LHC at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt}

$$\begin{document}$$\sqrt{s}=13\,\text {Te}\text {V} $$\end{document}$$ is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$$\,\text {cm}$$\end{document}$$ and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$$\,\text {fb}^{-1}$$\end{document}$$ in the \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} {{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} $$\end{document}$$ channel ( \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} {\upmu } $$\end{document}$$ and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${\upmu } {\upmu } $$\end{document}$$ channels). The search is designed to be sensitive to a wide range of models with displaced \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} {\upmu } $$\end{document}$$ , \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} {{\mathrm{e}}_{\mathrm{}}^{\mathrm{}}} $$\end{document}$$ , and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} $$\begin{document}$${\upmu } {\upmu } $$\end{document}$$ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.