Search for decays of the Higgs boson into scalar particles decaying into four or six $b$-quarks using $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$ with the ATLAS detector

Abstract

A search for exotic decays of the Higgs boson $H$ into new scalar or pseudoscalar particles that subsequently decay into $b$-quarks is presented. The search considers $ZH$ production with several decay scenarios for the Higgs boson: first to a pair of identical scalars, $H\to 2a\to 4b$, second to a pair of scalars with different masses ($m_{a1}<m_{a2}$), either directly, $H\to a_1{a}_2\to 4b$, or via a longer decay chain, $H\to a_1{a}_2\to 3a_1\to 6b$. The analysis uses proton-proton collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of $140{\mathrm{fb}}^{-1}$. No significant excess above the Standard Model prediction is observed. The search sets upper limits at 95% confidence level on the ratio of the Higgs boson production cross-section to the SM prediction times the branching ratio of Higgs bosons decaying into $4b$ or $6b$, between 4% and 25% for $\sigma (ZH)/{\sigma }_{\text{SM}}(ZH)\times \mathcal{B}$($H\to 2a\to 4b$), between 24% and 38% for $\sigma (ZH)/{\sigma }_{\text{SM}}(ZH)\times \mathcal{B}$($H\to a_1{a}_2\to 4b$), and between 10% and 20% for $\sigma (ZH)/{\sigma }_{\text{SM}}(ZH)\times \mathcal{B}$($H\to a_1{a}_2\to 3a_1\to 6b$), depending on the masses of the scalar particles.

arXiv comment67 pages in total, author list starting page 50, 15 figures, 10 tables. All figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HMBS-2024-26/

References in corpus (117)

• XGBoost: A Scalable Tree Boosting System
• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• The anti-k_t jet clustering algorithm
• A Brief Introduction to PYTHIA 8.1
• FastJet user manual
• Asymptotic formulae for likelihood-based tests of new physics
• A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX
• A New Method for Combining NLO QCD with Shower Monte Carlo Algorithms
• Matching NLO QCD computations with Parton Shower simulations: the POWHEG method
• Parton distributions for the LHC Run II
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• Confidence Level Computation for Combining Searches with Small Statistics
• PDF4LHC recommendations for LHC Run II
• Dispelling the N^3 myth for the Kt jet-finder
• The total top quark pair production cross-section at hadron colliders through O(alpha_S^4)
• Scattering Amplitudes with Open Loops
• Top++: a program for the calculation of the top-pair cross-section at hadron colliders
• Secluded WIMP Dark Matter
• A parton shower algorithm based on Catani-Seymour dipole factorisation
• Successive Combination Jet Algorithm For Hadron Collisions
• QCD Matrix Elements + Parton Showers
• Comix, a new matrix element generator
• Event Generation with Sherpa 2.2
• Pileup subtraction using jet areas
• QCD matrix elements + parton showers: The NLO case
• High-precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO
• Performance of the ATLAS Trigger System in 2015
• Two-loop soft anomalous dimensions for single top quark associated production with a W- or H-
• QCD matrix elements and truncated showers
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Percent level precision physics at the Tevatron: first genuine NNLO QCD corrections to q qbar -> t tbar + X
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels
• NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction
• A critical appraisal of NLO+PS matching methods
• Production and Integration of the ATLAS Insertable B-Layer
• Performance of pile-up mitigation techniques for jets in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detector
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• Hadronic top-quark pair production with NNLL threshold resummation
• Collider Probes of Axion-Like Particles
• A portrait of the Higgs boson by the CMS experiment ten years after the discovery
• Trial factors for the look elsewhere effect in high energy physics
• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
• Measurement of the $Z/{\gamma }^{\ast }$ boson transverse momentum distribution in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the ATLAS detector
• ATLAS $b$-jet identification performance and efficiency measurement with $t\bar{t}$ events in $pp$ collisions at $\sqrt{s}=13$ TeV
• Jet reconstruction and performance using particle flow with the ATLAS Detector
• Exotic Decays of the 125 GeV Higgs Boson
• HATHOR for single top-quark production: Updated predictions and uncertainty estimates for single top-quark production in hadronic collisions
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 $pp$ collision data set at $\sqrt{s}=13$ TeV
• Jet Substructure at the Large Hadron Collider: A Review of Recent Advances in Theory and Machine Learning
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Status of the Higgs Singlet Extension of the Standard Model after LHC Run 1
• Jet energy scale and resolution measured in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Performance of the ATLAS muon triggers in Run 2
• NNLOPS simulation of Higgs boson production
• Escaping the Large Fine Tuning and Little Hierarchy Problems in the Next to Minimal Supersymmetric Model and h-> aa Decays
• Measurement of the Inelastic Proton-Proton Cross Section at $\sqrt{s}=13$ TeV with the ATLAS Detector at the LHC
• A Renormalizable Model for the Galactic Center Gamma Ray Excess from Dark Matter Annihilation
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Nonstandard Higgs Boson Decays
• Light Axion within the Next-to-Minimal Supersymmetric Standard Model
• Performance of the ATLAS Track Reconstruction Algorithms in Dense Environments in LHC Run 2
• Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector
• Evidence for the $H\to b\bar{b}$ decay with the ATLAS detector
• ATLAS flavour-tagging algorithms for the LHC Run 2 $pp$ collision dataset
• LHC Benchmark Scenarios for the Real Higgs Singlet Extension of the Standard Model
• Fitting the Galactic Center Gamma-Ray Excess with Cascade Annihilations
• Discovering Uncolored Naturalness in Exotic Higgs Decays
• Search for new phenomena in events with at least three photons collected in $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector
• Search for charged Higgs bosons decaying into a top quark and a bottom quark at $\sqrt{s}$=13 TeV with the ATLAS detector
• Reweighting QCD matrix-element and parton-shower calculations
• Dark Light Higgs
• Measurement of the $c$-jet mistagging efficiency in $t\bar{t}$ events using $pp$ collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector
• Precise Higgs-background predictions: merging NLO QCD and squared quark-loop corrections to four-lepton + 0,1 jet production
• Two-real-scalar-singlet extension of the SM: LHC phenomenology and benchmark scenarios
• Jets from Jets: Re-clustering as a tool for large radius jet reconstruction and grooming at the LHC
• Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two b quarks and two $\tau$ leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state with two muons and two b quarks in pp collisions at 13 TeV
• Electroweak phase transition with spontaneous $Z_2$-breaking
• Performance of the missing transverse momentum triggers for the ATLAS detector during Run-2 data taking
• Calibration of the light-flavour jet mistagging efficiency of the $b$-tagging algorithms with $Z$+jets events using 139 ${\mathrm{fb}}^{-1}$ of ATLAS proton-proton collision data at $\sqrt{s}=13$ TeV
• Search for the Higgs boson produced in association with a vector boson and decaying into two spin-zero particles in the $H\to aa\to 4b$ channel in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for Higgs boson decays to beyond-the-Standard-Model light bosons in four-lepton events with the ATLAS detector at $\sqrt{s}=13$ TeV
• Search for light bosons in decays of the 125 GeV Higgs boson in proton-proton collisions at sqrt(s) = 8 TeV
• Exotic Higgs Decays and the Electroweak Phase Transition
• Measurements of fiducial and differential cross-sections of $t\bar{t}$ production with additional heavy-flavour jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
• Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in the final state of two muons and two $\tau$ leptons in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Software and computing for Run 3 of the ATLAS experiment at the LHC
• Search for Higgs boson decays into a pair of light bosons in the $bb\mu \mu$ final state in $pp$ collision at $\sqrt{s}=$13 TeV with the ATLAS detector
• Collider constraints on light pseudoscalars
• Search for light pseudoscalar boson pairs produced from decays of the 125 GeV Higgs boson in final states with two muons and two nearby tracks in pp collisions at $\sqrt{s}=$ 13 TeV
• Search for a light pseudoscalar Higgs boson in the boosted $\mu \mu \tau \tau$ final state in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for Higgs boson decays into two new low-mass spin-0 particles in the 4$b$ channel with the ATLAS detector using $pp$ collisions at $\sqrt{s}=13$ TeV
• Estimating the significance of a signal in a multi-dimensional search
• Search for new light gauge bosons in Higgs boson decays to four-lepton final states in $pp$ collisions at $\sqrt{s}=8$ TeV with the ATLAS detector at the LHC
• Search for Higgs boson decays into pairs of light (pseudo)scalar particles in the $\gamma \gamma jj$ final state in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for a very light NMSSM Higgs boson produced in decays of the 125 GeV scalar boson and decaying into tau leptons in pp collisions at sqrt(s) = 8 TeV
• Measurement of Higgs boson decay into $b$-quarks in associated production with a top-quark pair in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for Higgs boson decays into a pair of pseudoscalar particles in the $bb\mu \mu$ final state with the ATLAS detector in $pp$ collisions at $\sqrt{s}=13$ TeV
• Modified Higgs Boson Phenomenology from Gauge or Gaugino Mediation in the NMSSM
• Electron and photon efficiencies in LHC Run 2 with the ATLAS experiment
• Measurement of the $t\bar{t}t\bar{t}$ production cross section in $pp$ collisions at $\sqrt{s}$=13 TeV with the ATLAS detector
• Search for the Higgs boson produced in association with a $W$ boson and decaying to four $b$-quarks via two spin-zero particles in $pp$ collisions at 13 TeV with the ATLAS detector
• Modelling and computational improvements to the simulation of single vector-boson plus jet processes for the ATLAS experiment
• Search for Higgs bosons decaying into new spin-0 or spin-1 particles in four-lepton final states with the ATLAS detector with 139 fb${}^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV
• Search for the exotic decay of the Higgs boson into two light pseudoscalars with four photons in the final state in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Electron and photon energy calibration with the ATLAS detector using LHC Run 2 data
• Search for exotic Higgs boson decays H $\to$ $\mathcal{AA}$ $\to$ 4$\gamma$ with events containing two merged diphotons in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• 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
• New techniques for jet calibration with the ATLAS detector
• Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the $\mu \mu$bb and $\tau \tau$bb final states
• Search for the decay of the Higgs boson to a pair of light pseudoscalar bosons in the final state with four bottom quarks in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Search for decays of the Higgs boson into a pair of pseudoscalar particles decaying into $b\bar{b}{\tau }^{+}{\tau }^{-}$ using $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Calibration of a soft secondary vertex tagger using proton-proton collisions at $\sqrt{s}=$13 TeV with the ATLAS detector