Çetin, Serkant Ali2020-06-022020-06-022020-02-101873-24450370-2693https://hdl.handle.net/11411/2125https://doi.org/10.1016/j.physletb.2019.135145A search for non-resonant Higgs boson pair production, as predicted by the Standard Model, is presented, where one of the Higgs bosons decays via the H -> bb channel and the other via one of the H -> WW*/ZZ*/tau tau channels. The analysis selection requires events to have at least two b-tagged jets and exactly two leptons (electrons or muons) with opposite electric charge in the final state. Candidate events consistent with Higgs boson pair production are selected using a multi-class neural network discriminant. The analysis uses 139 fb(-1) of pp collision data recorded at a centre-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. An observed (expected) upper limit of 1.2 (0.9(-0.3)(+0.4)) pb is set on the non-resonant Higgs boson pair production cross-section at 95% confidence level, which is equivalent to 40 (29(-9)(+14)) times the value predicted in the Standard Model.eninfo:eu-repo/semantics/openAccessTop-Quark PairHadron CollidersLhcEventsArticle2-s2.0-8507683825410.1016/j.physletb.2019.135145Q2WOS:000508018500037