Search for heavy charged long-lived particles in proton–proton collisions at √s=13 TeV using an ionisation measurement with the ATLAS detector Aaboud, M. Aguilar Saavedra, Juan Antonio Atlas Collaboration The crucial computing support from all WLCG partners is ac-knowledged gratefully, in particular from CERN, the ATLAS Tier-1facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Swe-den), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA), the Tier-2 facilities worldwide and large non-WLCG resource providers. Major contributors of computing resources are listed in Ref.[62]. This Letter presents a search for heavy charged long-lived particles produced in proton–proton collisions at √s=13 TeV at the LHC using a data sample corresponding to an integrated luminosity of 36.1fb−1 collected by the ATLAS experiment in 2015 and 2016. These particles are expected to travel with a velocity significantly below the speed of light, and therefore have a specific ionisation higher than any high-momentum Standard Model particle of unit charge. The pixel subsystem of the ATLAS detector is used in this search to measure the ionisation energy loss of all reconstructed charged particles which traverse the pixel detector. Results are interpreted assuming the pair production of R-hadrons as composite colourless states of a long-lived gluino and Standard Model partons. No significant deviation from Standard Model background expectations is observed, and lifetime-dependent upper limits on R-hadron production cross-sections and gluino masses are set, assuming the gluino always decays to two quarks and a 100 GeV stable neutralino. R-hadrons with lifetimes above 1.0ns are excluded at the 95% confidence level, with lower limits on the gluino mass ranging between 1290GeV and 2060GeV. In the case of stable R-hadrons, the lower limit on the gluino mass at the 95% confidence level is 1890GeV. 2019-11-22T11:30:51Z 2019-11-22T11:30:51Z 2018-11-01 info:eu-repo/semantics/article The ATLAS Collaboration. Physics Letters B 788 (2019) 96–116 [https://doi.org/10.1016/j.physletb.2018.10.055] http://hdl.handle.net/10481/58027 10.1016/j.physletb.2018.10.055 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Elsevier B.V.