Search for direct top squark pair production in events with a Z boson, b-jets and missing transverse momentum in √s = 8 TeV pp collisions with the ATLAS detector

G Aad; B Abbott; J Abdallah; SA Khalek; O Abdinov; R Aben; B Abi; M Abolins; OSA Zeid; H Abramowicz; H Abreu; R Abreu; Y Abulaiti; BS Acharya; L Adamczyk; DL Adams; J Adelman; S Adomeit; T Adye; T Agatonovic-Jovin; JA Aguilar-Saavedra; M Agustoni; SP Ahlen; A Ahmad; F Ahmadov; G Aielli; TPA Åkesson; G Akimoto; AV Akimov; GL Alberghi; J Albert; S Albrand; MJA Verzini; M Aleksa; IN Aleksandrov; C Alexa; G Alexander; G Alexandre; T Alexopoulos; M Alhroob; G Alimonti; L Alio; J Alison; BMM Allbrooke; LJ Allison; PP Allport; SE Allwood-Spiers; J Almond; A Aloisio; A Alonso; F Alonso; C Alpigiani; A Altheimer; BA Gonzalez; MG Alviggi; K Amako; YA Coutinho; C Amelung; D Amidei; SPA Dos Santos; A Amorim; S Amoroso; N Amram; G Amundsen; C Anastopoulos; LS Ancu; N Andari; T Andeen; CF Anders; G Anders; KJ Anderson; A Andreazza; V Andrei; XS Anduaga; S Angelidakis; I Angelozzi; P Anger; A Angerami; F Anghinolfi; AV Anisenkov; N Anjos; A Annovi; A Antonaki; M Antonelli; A Antonov; J Antos; F Anulli; M Aoki; LA Bella; R Apolle; G Arabidze; I Aracena; Y Arai; JP Araque; ATH Arce; JF Arguin; S Argyropoulos; M Arik; AJ Armbruster; O Arnaez

Journal article

Search for direct top squark pair production in events with a Z boson, b-jets and missing transverse momentum in √s = 8 TeV pp collisions with the ATLAS detector

G Aad, B Abbott, J Abdallah, SA Khalek, O Abdinov, R Aben, B Abi, M Abolins, OSA Zeid, H Abramowicz, H Abreu, R Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, J Adelman, S Adomeit, T Adye, T Agatonovic-Jovin Show all

European Physical Journal C | Published : 2014

DOI: 10.1140/epjc/s10052-014-2883-6

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Abstract

A search is presented for direct top squark pair production using events with at least two leptons including a same-flavour opposite-sign pair with invariant mass consistent with the Z boson mass, jets tagged as originating from b-quarks and missing transverse momentum. The analysis is performed with proton–proton collision data at √s = 8 TeV collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20.3 fb−1. No excess beyond the Standard Model expectation is observed. Interpretations of the results are provided in models based on the direct pair production of the heavier top squark state (t2) followed by the decay to the lighter top squark state (t1)..

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University of Melbourne Researchers

Federico Scutti Author

Elisabetta Barberio Author

Matteo Volpi Author

G. N. Taylor Author

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ARC CENTRE OF EXCELLENCE FOR PARTICLE PHYSICS AT THE TERA-SCALE

The Large Hadron Collider, a gigantic particle accelerator at the CERN laboratory in Europe, has commenced operation. It will discover how p..

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Awarded by National Science Foundation

Funding Acknowledgements

We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWF and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIEN-CIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET, ERC and NSRF, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT and NSRF, Greece; ISF, MINERVA, GIF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW and NCN, Poland; GRICES and FCT, Portugal; MNE/IFA, Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MIZS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey; STFC, the Royal Society and Leverhulme Trust, UK; DOE and NSF, USA. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN and the ATLAS Tier-1 facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwide.