Prospects for observing ultra-rare triboson processes at the Large Hadron Collider

The electroweak sector of the Standard Model (SM), specifically its non-Abelian gauge structure, predicts the production of multiple gauge bosons in a single LHC collision event. Multibosons allow us to probe several unique interactions in the SM and look for subtle signs of New Physics. In this talk, we present a feasibility study of observing the ultra-rare triboson processes, WZZ and ZZZ, with multivariate machine learning (ML) techniques. These processes are yet to be observed at the LHC due to their low production cross sections. Observation is possible only if state-of-the-art ML techniques are used in addition to extensive feature engineering. Our study assumes a dataset of 425 fb^-1 consistent with data from the LHC at √s = 13 and 13.6 TeV. The parametrized detector simulation framework, Delphes, has been used to model detector responses of the signal and the background processes, which have been generated at parton level with Madgraph_aMC@NLO and showered with PYTHIA. Both resonant (or Higgs mediated) and non-resonant modes of signal production are studied in three, four, and five lepton final states. We report significances in each of these final states and a combined significance for the observation of these ultra-rare processes with the current data at the LHC.