Searches for new phenomena in events with two leptons, jets, and missing transverse momentum in 139 fb$$^{-1}$$ of $$\varvec{\sqrt{s}}=13$$ TeV $$\varvec{pp}$$ collisions with the ATLAS detector

Abstract

Searches for new phenomena inspired by supersymmetry in final states containing an $$e^+e^-$$ e + e - or $$\mu ^+\mu ^-$$ μ + μ - pair, jets, and missing transverse momentum are presented. These searches make use of proton–proton collision data with an integrated luminosity of $$139~\text {fb}^{-1}$$ 139 fb - 1 , collected during 2015–2018 at a centre-of-mass energy $$\sqrt{s}=13~$$ s = 13 TeV by the ATLAS detector at the Large Hadron Collider. Two searches target the pair production of charginos and neutralinos. One uses the recursive-jigsaw reconstruction technique to follow up on excesses observed in $$36.1~\text {fb}^{-1}$$ 36.1 fb - 1 of data, and the other uses conventional event variables. The third search targets pair production of coloured supersymmetric particles (squarks or gluinos) decaying through the next-to-lightest neutralino $$(\tilde{\chi }_2^0)$$ ( χ ~ 2 0 ) via a slepton $$(\tilde{\ell })$$ ( ℓ ~ ) or Z boson into $$\ell ^+\ell ^-\tilde{\chi }_1^0$$ ℓ + ℓ - χ ~ 1 0 , resulting in a kinematic endpoint or peak in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectations. Results are interpreted using simplified models and exclude masses up to 900 GeV for electroweakinos, 1550 GeV for squarks, and 2250 GeV for gluinos.

SModelS v2.3: Enabling global likelihood analyses

“…Concretely, the following results were added corresponding to the availability of appropriate public numerical material on HEPDATA: 5 Gluino/squark searches: In this category, we added UL results from two CMS analyses, the search in final states with jets plus leptons CMS-SUS-19-008 [33] and the search in final states with jets plus highly boosted Z-bosons CMS-SUS-19-013 [34]. From ATLAS, we added the gluino/squark UL and EM results from the search in final states with jets plus two leptons, ATLAS-SUSY-2018-05 [35].…”

“…Electroweak searches: These constitute the most important part of this database update. We added UL and EM results from ATLAS covering a large variety of EW-ino searches at Run 2; these are four searches in leptonic channels, 6 ATLAS-SUSY-2018-05 (2 leptons) [35], ATLAS-SUSY-2018-32 (2 OS leptons) [29], ATLAS-SUSY-2019-02 (soft leptons) [44] and ATLAS-SUSY-2019-09 (3 leptons) [30], as well as the fully hadronic search ATLAS-SUSY-2018-41 [31]. For all these, the combination of SRs is enabled either through a HISTFACTORY statistical model or a covariance matrix.…”

Searches for Supersymmetry with the ATLAS and CMS detectors

“…This ATLAS analysis presents searches for new phenomena in final states with exactly two oppositely charged same-flavour leptons, jets and 𝐸 miss T [16], which applies a shape fit [17] in the dilepton invariant mass, 𝑚 ℓℓ , distribution. The analysis is split into three searches probing both strong and EW sparticle production.…”

“…The red dotted lines around the observed limit indicate the signal cross-section uncertainty. From [16].…”

“…The dashed line and yellow band indicate the expected limit and the 1𝜎 experimental uncertainties.The red dotted lines around the observed limit indicate the signal cross-section uncertainty. From[16].…”