A ternary approach to the four top quark discovery at LHC

Since the start of the Large Hadron Collider (LHC) at 13 TeV, the CMS experiment recorded a proton- proton collisions data set amounting to 150/fb. The heaviest known elementary particle of the standard model, the top quark, has been observed again, and first measurements of its properties enter the precision regime. With the next run of the LHC the data set will at least double, allowing for the discovery of an extremely rare process, the production of four top quarks. For this extraordinary opportunity, three teams join forces to tackle the formidable challenges. Two experimental teams focus on extracting every last bit of information from the events using novel machine learning tools. The goal is to optimally reduce fiendishly difficult backgrounds that can mimic the signal events. Building on year-long expertise, the HEPHY team (ÖAW) targets the events with up to one lepton, while the UGent (BE) team focuses on events with two or more leptons. But events with four top quarks have further peculiar properties. They depend sensitively on many hypothetical deviations from the standard model of particle physics. Exploiting this dependence is the goal of the third team at UNIGE (CH). Small deviations in the decay products` kinematic properties are used to confront the big questions of particle physics. Is the standard model valid after all, or do we have to replace it with something new? Beyond this, a discovery of the four-top process with more than 5 sigma, the conventional gold standard in particle physics, will be a landmark achievement for the CMS experiment and the LHC.