Search for heavy neutral Higgs bosons A and H in the tt¯Z channel in proton-proton collisions at √s = 13 TeV

Abstract

A direct search for new heavy neutral Higgs bosons [Figure presented] and [Figure presented] in the [Figure presented] channel is presented, targeting the process [Figure presented] with [Figure presented]. For the first time, the channel with decays of the [Figure presented] boson to muons or electrons in association with all-hadronic decays of the [Figure presented] system is targeted. The analysis uses proton-proton collision data collected at the CERN LHC with the CMS experiment at s=13TeV, which correspond to an integrated luminosity of 138fb−1. No signal is observed. Upper limits on the product of the cross section and branching fractions are derived for narrow resonances [Figure presented] and [Figure presented] with masses up to 2100 and 2000 GeV, respectively, assuming [Figure presented] boson production through gluon fusion. The results are also interpreted within two-Higgs-doublet models, where [Figure presented] and [Figure presented] are CP-odd and CP-even states, respectively, complementing and substantially extending the reach of previous searches. © 2025 CERN for the benefit of the CMS Collaboration