Searches for scalar leptoquarks and differential cross-section measurements in dilepton–dijet events in proton–proton collisions at a centre-of-mass energy of √s = 13 TeV with the ATLAS experiment

Research output: Contribution to journalArticlepeer-review

Authors

  • ATLAS Collaboration

Colleges, School and Institutes

Abstract

Searches for scalar leptoquarks pair-produced in proton–proton collisions at √s=13 TeV at the Large Hadron Collider are performed by the ATLAS experiment. A data set corresponding to an integrated luminosity of 36.1 fb - 1 is used. Final states containing two electrons or two muons and two or more jets are studied, as are states with one electron or muon, missing transverse momentum and two or more jets. No statistically significant excess above the Standard Model expectation is observed. The observed and expected lower limits on the leptoquark mass at 95% confidence level extend up to 1.29 TeV and 1.23 TeV for first- and second-generation leptoquarks, respectively, as postulated in the minimal Buchmüller–Rückl–Wyler model, assuming a branching ratio into a charged lepton and a quark of 50%. In addition, measurements of particle-level fiducial and differential cross sections are presented for the Z→ ee, Z→ μμ and tt¯ processes in several regions related to the search control regions. Predictions from a range of generators are compared with the measurements, and good agreement is seen for many of the observables. However, the predictions for the Z→ ℓℓ measurements in observables sensitive to jet energies disagree with the data.

Bibliographic note

62 pages in total, author list starting page 46, 19 figures, 5 tables, published in EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2016-08/

Details

Original languageEnglish
Article number733
Number of pages45
JournalEuropean Physical Journal C
Volume79
Issue number9
Early online date3 Sep 2019
Publication statusE-pub ahead of print - 3 Sep 2019

Keywords

  • hep-ex