Search for a CP-odd Higgs boson decaying into a heavy CP-even Higgs boson and a $Z$ boson in the ${\ell }^{+}{\ell }^{-}t\bar{t}$ and $\nu \bar{\nu }b\bar{b}$ final states using 140 fb${}^{-1}$ of data collected with the ATLAS detector

Abstract

A search for a heavy CP-odd Higgs boson, $A$, decaying into a $Z$ boson and a heavy CP-even Higgs boson, $H$, is presented. It uses the full LHC Run 2 dataset of $pp$ collisions at $\sqrt{s}=13$ TeV collected with the ATLAS detector, corresponding to an integrated luminosity of $140$ fb${}^{-1}$. The search for $A\to ZH$ is performed in the ${\ell }^{+}{\ell }^{-}t\bar{t}$ and $\nu \bar{\nu }b\bar{b}$ final states and surpasses the reach of previous searches in different final states in the region with $m_H>350$ GeV and $m_A>800$ GeV. No significant deviation from the Standard Model expectation is found. Upper limits are placed on the production cross-section times the decay branching ratios. Limits with less model dependence are also presented as functions of the reconstructed $m(t\bar{t})$ and $m(b\bar{b})$ distributions in the ${\ell }^{+}{\ell }^{-}t\bar{t}$ and $\nu \bar{\nu }b\bar{b}$ channels, respectively. In addition, the results are interpreted in the context of two-Higgs-doublet models.

56 pages in total, author list starting page 39, 12 figures, 7 tables, published in JHEP02(2024)197. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2021-02

References in corpus (21)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• An Introduction to PYTHIA 8.2
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Herwig++ Physics and Manual
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Single-top Wt-channel production matched with parton showers using the POWHEG method
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Automatic spin-entangled decays of heavy resonances in Monte Carlo simulations
• Single-top hadroproduction in association with a W boson
• SusHi: A program for the calculation of Higgs production in gluon fusion and bottom-quark annihilation in the Standard Model and the MSSM
• HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions
• Robust Independent Validation of Experiment and Theory: Rivet version 3
• Higgs boson production in association with top quarks in the POWHEG BOX
• vh@nnlo - Higgs Strahlung at hadron colliders
• Strong First Order Electroweak Phase Transition in the CP-Conserving 2HDM Revisited
• Associated ZH production at hadron colliders: the fully differential NNLO QCD calculation
• Echoes of the Electroweak Phase Transition: Discovering a second Higgs doublet through $A_0\to H_{0}Z$
• Soft gluon resummation for gluon-induced Higgs Strahlung
• Automation of the matrix element reweighting method
• Fast simulation of detector effects in Rivet

Cited by in corpus (1)

• The performance of missing transverse momentum reconstruction and its significance with the ATLAS detector using 140 fb${}^{-1}$ of $\sqrt{s}=13$ TeV $pp$ collisions