Search for a heavy Higgs boson decaying into a Z boson and another heavy Higgs boson in the llbb and llWW final state in 13 TeV pp collision with ATLAS detector

In this talk a search for a Higgs boson cascade in the context of the two-Higgs-Doublet Model is presented. In this cascade, a heavy Higgs boson A decays to ZH, where H is another heavy Higgs boson with mass > 125 GeV. Subsequently, the Z boson decay leptonically and the H boson into a pair of b-quarks or W bosons. The search is motivated by the mechanism which generates the matter-antimatter asymmetry in the context of extended Higgs sectors, known as electroweak baryogenesis. In the context of 2HDM, this mechanism requires large mass splitting between the two heavier Higgs bosons. The A boson is assumed to be produced via gluon-fusion and b-associated production in the mass range 230-800 GeV and to decay to the H boson in the mass range 130-700 GeV. The search uses a data sample corresponding to an integrated luminosity 139 fb-1 from proton-proton collision data at a center-of-mass of 13 TeV recorded between 2015 and 2018 by the ATLAS detector at the LHC. The latest results for A->ZH and their interpretation in the context of 2HDM will be reported.