Abstract

A data sample of events from proton–proton collisions with two isolated same-sign leptons, missing transverse momentum, and jets is studied in a search for signatures of new physics phenomena by the CMS Collaboration at the LHC. The data correspond to an integrated luminosity of 35.9,text {fb}^{-text {1}}, and a center-of-mass energy of 13,text {TeV}. The properties of the events are consistent with expectations from standard model processes, and no excess yield is observed. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos, squarks, and same-sign top quarks, as well as top-quark associated production of a heavy scalar or pseudoscalar boson decaying to top quarks, and on the standard model production of events with four top quarks. The observed lower mass limits are as high as 1500,text {GeV} for gluinos, 830,text {GeV} for bottom squarks. The excluded mass range for heavy (pseudo)scalar bosons is 350–360 (350–410),text {GeV}. Additionally, model-independent limits in several topological regions are provided, allowing for further interpretations of the results.

Highlights

  • Final states with two leptons of same charge, denoted as same-sign (SS) dileptons, are produced rarely by standard model (SM) processes in proton–proton collisions

  • This paper extends the search for new physics presented in Ref. [24]

  • We provide limits on the number of SS dilepton pairs as a function of the ETmiss and HT thresholds in the kinematic tails, as well as results from a smaller number of inclusive and exclusive signal regions

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Summary

Introduction

Final states with two leptons of same charge, denoted as same-sign (SS) dileptons, are produced rarely by standard model (SM) processes in proton–proton (pp) collisions. A large number of new physics mechanisms have been proposed to extend the SM and address its shortcomings Many of these can give rise to potentially large contributions to the SS dilepton signature, e.g., the production of supersymmetric (SUSY) particles [1,2], SS top quarks [3,4], scalar gluons (sgluons) [5,6], heavy scalar. While R-parity conserving SUSY models often lead to signatures with large ETmiss, it is interesting to study final states without significant ETmiss beyond what is produced by the neutrinos from leptonic W boson decays. The full analysis results are summarized in a smaller set of exclusive regions to be used in combination with the background correlation matrix to facilitate their reinterpretation

Background and signal simulation
The CMS detector and event reconstruction
Event selection and search strategy
Backgrounds
Systematic uncertainties
Results and interpretation
Model-independent limits and additional results
Full Text
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