Search for long-lived charged particles using large specific ionisation loss and time of flight in 140 fb-1 of pp collisions at SQUARE ROOTs = 13 TeV with the ATLAS detector

Abstract

This paper presents a search for massive, charged, long-lived particles with theATLAS detector at the Large Hadron Collider using an integrated luminosity of 140 fb-1 ofproton-proton collisions at SQUARE ROOTs = 13TeV. These particles are expected to move significantlyslower than the speed of light. In this paper, two signal regions provide complementarysensitivity. In one region, events are selected with at least one charged-particle track withhigh transverse momentum, large specific ionisation measured in the pixel detector, andtime of flight to the hadronic calorimeter inconsistent with the speed of light. In the otherregion, events are selected with at least two tracks of opposite charge which both have a hightransverse momentum and an anomalously large specific ionisation. The search is sensitiveto particles with lifetimes greater than about 3 ns with masses ranging from 200 GeV to3TeV. The results are interpreted to set constraints on the supersymmetric pair productionof long-lived R-hadrons, charginos and staus, with mass limits extending beyond those fromprevious searches in broad ranges of lifetime.