Search for new phenomena in final states with two leptons and one or no $b$-tagged jets at $\sqrt{s}=13$ TeV using the ATLAS detector

Abstract

A search for new phenomena is presented in final states with two leptons and one or no $b$-tagged jets. The event selection requires the two leptons to have opposite charge, the same flavor (electrons or muons), and a large invariant mass. The analysis is based on the full Run-2 proton-proton collision dataset recorded at a center-of-mass energy of $\sqrt{s}=13$ TeV by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 139 fb${}^{-1}$. No significant deviation from the expected background is observed in the data. A four-fermion contact interaction between two quarks ($b,s$) and two leptons ($ee$ or $\mu \mu$), inspired by the $B$-meson decay anomalies, is used as a benchmark signal model. This model is characterized by the energy scale and coupling, $\Lambda$ and $g_{\ast }$ respectively. Contact interactions with $\Lambda /g_{\ast }$ lower than 2.0 (2.4) TeV are excluded for electrons (muons) at the 95% confidence level, still far below the value which is favored by the $B$-meson decay anomalies. In addition, model-independent limits are set as a function of the selection on the dilepton invariant mass, which allows the results to be reinterpreted in other signal scenarios.

32 pages in total, author list starting page 12, 4 figures, 1 table, submitted to PRL. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/EXOT-2018-16/

References in corpus (14)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• New parton distributions for collider physics
• Event generation with SHERPA 1.1
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Single-top hadroproduction in association with a W boson
• NLO vector-boson production matched with shower in POWHEG
• Measurement of the $Z/{\gamma }^{\ast }$ boson transverse momentum distribution in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector
• Search for lepton-universality violation in $B^{+}\to K^{+}{\ell }^{+}{\ell }^{-}$ decays
• Search for high-mass dilepton resonances in pp collisions at sqrt(s) = 8 TeV with the ATLAS detector
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Search for new high-mass phenomena in the dilepton final state using 36 fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• New flavor physics in di- and tri-lepton events from single-top at the LHC and beyond

Cited by in corpus (6)

• Third order fiducial predictions for Drell-Yan at the LHC
• Hints of Natural Supersymmetry in Flavor Anomalies?
• Multi-lepton probes of new physics and lepton-universality in top-quark interactions
• Probing B-Anomalies via Dimuon Tails at a Future Collider
• Generic tests of CP-violation in high-$p_{\text{T}}$ multi-lepton signals at the LHC and beyond
• Searches for Leptoquarks with the ATLAS Detector