Search for long-lived stopped R-hadrons decaying out of time with pp collisions using the ATLAS detector

G Aad; T Abajyan; B Abbott; J Abdallah; S Abdel Khalek; O Abdinov; R Aben; B Abi; M Abolins; OS Abou Zeid; H Abramowicz; H Abreu; Y Abulaiti; BS Acharya; L Adamczyk; DL Adams; TN Addy; J Adelman; S Adomeit; T Adye; S Aefsky; T Agatonovic-Jovin; JA Aguilar-Saavedra; M Agustoni; SP Ahlen; A Ahmad; F Ahmadov; M Ahsan; G Aielli; TPA Åkesson; G Akimoto; AV Akimov; MA Alam; J Albert; S Albrand; MJ Alconada Verzini; M Aleksa; IN Aleksandrov; F Alessandria; C Alexa; G Alexander; G Alexandre; T Alexopoulos; M Alhroob; M Aliev; G Alimonti; L Alio; J Alison; BMM Allbrooke; LJ Allison; PP Allport; SE Allwood-Spiers; J Almond; A Aloisio; R Alon; A Alonso; F Alonso; A Altheimer; B Alvarez Gonzalez; MG Alviggi; K Amako; Y Amaral Coutinho; C Amelung; VV Ammosov; SP Amor Dos Santos; A Amorim; S Amoroso; N Amram; C Anastopoulos; LS Ancu; N Andari; T Andeen; CF Anders; G Anders; KJ Anderson; A Andreazza; V Andrei; XS Anduaga; S Angelidakis; P Anger; A Angerami; F Anghinolfi; AV Anisenkov; N Anjos; A Annovi; A Antonaki; M Antonelli; A Antonov; J Antos; F Anulli; M Aoki; L Aperio Bella; R Apolle; G Arabidze; I Aracena; Y Arai; ATH Arce; S Arfaoui; JF Arguin; S Argyropoulos

Journal article

Search for long-lived stopped R-hadrons decaying out of time with pp collisions using the ATLAS detector

G Aad, T Abajyan, B Abbott, J Abdallah, S Abdel Khalek, O Abdinov, R Aben, B Abi, M Abolins, OS Abou Zeid, H Abramowicz, H Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, TN Addy, J Adelman, S Adomeit, T Adye Show all

Physical Review D Particles Fields Gravitation and Cosmology | Published : 2013

DOI: 10.1103/PhysRevD.88.112003

Abstract

An updated search is performed for gluino, top squark, or bottom squark R-hadrons that have come to rest within the ATLAS calorimeter, and decay at some later time to hadronic jets and a neutralino, using 5.0 and 22:9 fb-1 of pp collisions at 7 and 8 TeV, respectively. Candidate decay events are triggered in selected empty bunch crossings of the LHC in order to remove pp collision backgrounds. Selections based on jet shape and muon system activity are applied to discriminate signal events from cosmic ray and beam-halo muon backgrounds. In the absence of an excess of events, improved limits are set on gluino, stop, and sbottom masses for different decays, lifetimes, and neutralino masses. Wit..

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University of Melbourne Researchers

Federico Scutti Author

Elisabetta Barberio Author

Matteo Volpi Author

G. N. Taylor Author

Grants

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; COLCIENCIAS, 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, DIP, and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW, 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, United Kingdom; DOE and NSF, United States of America. 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.