Search for short- and long-lived axion-like particles in $H\to aa\to 4\gamma$ decays with the ATLAS experiment at the LHC

Abstract

Presented is the search for anomalous Higgs boson decays into two axion-like particles (ALPs) using the full Run 2 data set of 140 fb${}^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS experiment. The ALPs are assumed to decay into two photons, providing sensitivity to recently proposed models that could explain the $(g-2{)}_{\mu }$ discrepancy. This analysis covers an ALP mass range from 100 MeV to 62 GeV and ALP-photon couplings in the range $10^{-5}{\text{TeV}}^{-1}<C_{a\gamma \gamma }/\Lambda <1{\text{TeV}}^{-1}$, and therefore includes signatures with significantly displaced vertices and highly collinear photons. No significant excess of events above the Standard Model background is observed. Upper limits at 95% confidence level are placed on the branching ratio of the Higgs boson to two ALPs in the four-photon final state, and are in the range of $10^{-5}$ to $3\times 10^{-2}$, depending on the hypothesized ALP mass and ALP-photon coupling strength.

arXiv comment45 pages in total, author list starting page 28, 9 figures, 2 tables, published in EPJc. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2019-19/

References in corpus (49)

• 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
• An Introduction to PYTHIA 8.2
• 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
• Final Report of the Muon E821 Anomalous Magnetic Moment Measurement at BNL
• Event generation with SHERPA 1.1
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• Measurement of the Positive Muon Anomalous Magnetic Moment to 0.46 ppm
• The anomalous magnetic moment of the muon in the Standard Model
• Secluded WIMP Dark Matter
• Event Generation with Sherpa 2.2
• Performance of the ATLAS Trigger System in 2015
• QCD matrix elements and truncated showers
• Inclusive Jet Production, Parton Distributions, and the Search for New Physics
• Production and Integration of the ATLAS Insertable B-Layer
• Electron and photon performance measurements with the ATLAS detector using the 2015-2017 LHC proton-proton collision data
• NLO Electroweak Corrections to Higgs Boson Production at Hadron Colliders
• Singlet Higgs Phenomenology and the Electroweak Phase Transition
• Collider Probes of Axion-Like Particles
• A portrait of the Higgs boson by the CMS experiment ten years after the discovery
• 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
• Exotic Decays of the 125 GeV Higgs Boson
• Calculation of the hadronic vacuum polarization contribution to the muon anomalous magnetic moment
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Probing MeV to 90 GeV axion-like particles with LEP and LHC
• Mixed QCD-electroweak corrections to Higgs boson production in gluon fusion
• A Renormalizable Model for the Galactic Center Gamma Ray Excess from Dark Matter Annihilation
• Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV
• Luminosity determination in $pp$ collisions at $\sqrt{s}=13$ TeV using the ATLAS detector at the LHC
• Light Axion within the Next-to-Minimal Supersymmetric Standard Model
• Extended gamma-ray emission from Coy Dark Matter
• Fitting the Galactic Center Gamma-Ray Excess with Cascade Annihilations
• Discovering Uncolored Naturalness in Exotic Higgs Decays
• Electroweak Baryogenesis from Exotic Electroweak Symmetry Breaking
• Search for new phenomena in events with at least three photons collected in $pp$ collisions at $\sqrt{s}$ = 8 TeV with the ATLAS detector
• $gg\to HH$: Combined Uncertainties
• Dark Light Higgs
• Combination of searches for invisible decays of the Higgs boson using 139 fb${}^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV collected with the ATLAS experiment
• Measurement of light-by-light scattering and search for axion-like particles with 2.2 nb${}^{-1}$ of Pb+Pb data with the ATLAS detector
• Heavy Higgs boson decays in the alignment limit of the 2HDM
• Measurement of the production cross section of three isolated photons in $pp$ collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector
• 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
• 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

Cited by in corpus (11)

• Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark
• The Muon Magnetic Moment and Physics Beyond the Standard Model
• Leptophilic Axion-like Particles at Forward Detectors
• The LHC as an Axion-Photon Collider
• Search for new resonances decaying to pairs of merged diphotons in proton-proton collisions at $\sqrt{s}$ = 13 TeV
• Concurrent Exploration of Axion-Like Particle Interactions with Gauge Bosons at the LHC
• Rare few-body decays of the Standard Model Higgs boson
• Improved Asymptotic Formulae for Statistical Interpretation Based on Likelihood Ratio Tests
• Di-decay signature of new physics particles at intensity frontier experiments
• Search for Higgs boson exotic decays into Lorentz-boosted light bosons in the four-$\tau$ final state at $\sqrt{s}=13$ TeV with the ATLAS detector
• Search for Higgs boson decays into a $Z$ boson and a light hadronically decaying resonance in $pp$ collisions at $\sqrt{s}$=13 TeV with the ATLAS detector