Evidence for the production of three massive vector bosons with the ATLAS detector

Abstract

A search for the production of three massive vector bosons in proton–proton collisions is performed using data at s=13 TeV recorded with the ATLAS detector at the Large Hadron Collider in the years 2015–2017, corresponding to an integrated luminosity of 79.8 fb?1. Events with two same-sign leptons ? (electrons or muons) and at least two reconstructed jets are selected to search for WWW?????qq. Events with three leptons without any same-flavour opposite-sign lepton pairs are used to search for WWW???????, while events with three leptons and at least one same-flavour opposite-sign lepton pair and one or more reconstructed jets are used to search for WWZ???qq??. Finally, events with four leptons are analysed to search for WWZ??????? and WZZ?qq????. Evidence for the joint production of three massive vector bosons is observed with a significance of 4.1 standard deviations, where the expectation is 3.1 standard deviations. © 2019 The Author(s)