Search for new phenomena using the invariant mass distribution of same-flavour opposite-sign dilepton pairs in events with missing transverse momentum in root s=13 TeV pp collisions with the ATLAS detector

Abstract

A search for new phenomena in final states containing an e(+)e(-) or m(+)m(-) pair, jets, and large missing transverse momentum is presented. This analysis makes use of proton-proton collision data with an integrated luminosity of 36.1 fb(-1), collected during 2015 and 2016 at a centre of-mass energy Os = 13 TeV with the ATLAS detector at the Large Hadron Collider. The search targets the pair production of supersymmetric coloured particles (squarks or gluinos) and their decays into final states containing an e(+)e(-) or m(+)m(-) pair and the lightest neutralino ((c) over tilde (0)(1)) via one of two next-to-lightest neutralino ((c) over tilde (0)(2)) decay mechanisms: (c) over tilde (0)(2) Z (c) over tilde (0)(1), where the Z boson decays leptonically leading to a peak in the dilepton invariant mass distribution around the Z boson mass; and (c) over tilde (0)(2) l(+)1(-) (c) over tilde (0)(1) with no intermediate l(+)l(-) resonance, yielding a kinematic endpoint in the dilepton invariant mass spectrum. The data are found to be consistent with the Standard Model expectation. Results are interpreted using simplified models, and exclude gluinos and squarks with masses as large as 1.85 and 1.3 TeV at 95% confidence level, respectively. ; ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW, Austria; FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, Brazil; FAPESP, Brazil; NSERC, Canada; NRC, Canada; CFI, Canada; CERN; CONICYT, Chile; CAS, China; MOST, China; NSFC, China; COLCIENCIAS, Colombia; MSMT CR, Czech Republic; MPO CR, Czech Republic; VSC CR, Czech Republic; DNRF, Denmark; DNSRC, Denmark; IN2P3-CNRS, France; CEA-DRF/IRFU, France; SRNSFG, Georgia; BMBF, Germany; HGF, Germany; MPG, Germany; GSRT, Greece; RGC, China; Hong Kong SAR, China; ISF, Israel; I-CORE, Israel; Benoziyo Center, Israel; INFN, Italy; MEXT, Japan; JSPS, Japan; CNRST, Morocco; NWO, Netherlands; RCN, Norway; MNiSW, Poland; NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia, Russian Federation; NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS, Slovenia; MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC, Sweden; Wallenberg Foundation, Sweden; SERI, Switzerland; SNSF, Switzerland; Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE, United States of America; NSF, United States of America; BCKDF; Canada Council; CANARIE; CRC; Compute Canada; FQRNT; Ontario Innovation Trust, Canada; EPLANET; ERC; ERDF; FP7, Horizon 2020; Marie Sklodowska-Curie Actions, European Union; Investissements d'Avenir Labex and Idex; ANR; Region Auvergne and Fondation Partager le Savoir, France; DFG; AvH Foundation, Germany; Herakleitos; Thales and Aristeia - EU-ESF; Greek NSRF; BSF; GIF; Minerva, Israel; BRF, Norway; CERCA Programme Generalitat de Catalunya, Spain; Generalitat Valenciana, Spain; Royal Society and Leverhulme Trust, United Kingdom; WLCG; ATLAS Tier-1 facilities at TRIUMF (Canada); NDGF (Denmark, Norway, Sweden); CC-IN2P3 (France); KIT/GridKA (Germany); INFN-CNAF (Italy); L-T1 (Netherlands); PIC (Spain); ASGC (Taiwan); RAL (UK); BNL (USA); Tier-2 facilities worldwide and large non-WLCG resource providers ; Open access journal. ; This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.