Search for exclusive Higgs and $Z$ boson decays to $\omega \gamma$ and Higgs boson decays to $K^{\ast }\gamma$ with the ATLAS detector

Abstract

Searches for the exclusive decays of the Higgs boson to an $\omega$ meson and a photon or a $K^{\ast }$ meson and a photon can probe flavour-conserving and flavour-violating Higgs boson couplings to light quarks, respectively. Searches for these decays, along with the analogous $Z$ boson decay to an $\omega$ meson and a photon, are performed with a $pp$ collision data sample corresponding to integrated luminosities of up to 134 fb${}^{-1}$ collected at $\sqrt{s}=13$ TeV with the ATLAS detector at the CERN Large Hadron Collider. The obtained 95% confidence-level upper limits on the respective branching fractions are $\mathcal{B}(H\to \omega \gamma )<5.5\times 10^{-4}$, $\mathcal{B}(H\to K^{\ast }\gamma )<2.2\times 10^{-4}$ and $\mathcal{B}(Z\to \omega \gamma )<3.9\times 10^{-6}$. The limits for $H\to \omega \gamma$ and $Z\to \omega \gamma$ are 370 times and 140 times the Standard Model expected values, respectively. The result for $Z\to \omega \gamma$ corresponds to a two-orders-of-magnitude improvement over the limit obtained by the DELPHI experiment at LEP.

arXiv comment37 pages in total, 4 figures, 2 tables, author list starts at page 20. Published in Physics Letters B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HDBS-2019-33

References in corpus (43)

• 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
• A Large Mass Hierarchy from a Small Extra Dimension
• A Brief Introduction to PYTHIA 8.1
• Asymptotic formulae for likelihood-based tests of new physics
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• Minimal Flavour Violation: an effective field theory approach
• Performance of the ATLAS Trigger System in 2015
• Production and Integration of the ATLAS Insertable B-Layer
• Topological cell clustering in the ATLAS calorimeters and its performance in LHC Run 1
• Kernel Estimation in High-Energy Physics
• NLO Electroweak Corrections to Higgs Boson Production at Hadron Colliders
• NNLO QCD corrections to the Higgs-strahlung processes at hadron colliders
• Luminosity determination in pp collisions at $\sqrt{s}$ = 8 TeV using the ATLAS detector at the LHC
• A portrait of the Higgs boson by the CMS experiment ten years after the discovery
• Electroweak and QCD corrections to Higgs production via vector-boson fusion at the LHC
• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
• Performance of electron and photon triggers in ATLAS during LHC Run 2
• Strong and electroweak corrections to the production of Higgs+2jets via weak interactions at the LHC
• Higgs production via vector-boson fusion at NNLO in QCD
• Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
• Higgs boson decays to quarkonia and the Hccbar coupling
• Measurement of $W^{\pm }$ and $Z$-boson production cross sections in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Evidence for Higgs boson decay to a pair of muons
• Higgs-dependent Yukawa couplings
• A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector
• An Exclusive Window onto Higgs Yukawa Couplings
• Evidence for the Higgs boson decay to a bottom quark-antiquark pair
• Measurement of the photon identification efficiencies with the ATLAS detector using LHC Run 2 data collected in 2015 and 2016
• Exclusive Radiative Higgs Decays as Probes of Light-Quark Yukawa Couplings
• Relativistic corrections to Higgs boson decays to quarkonia
• Prospects for measuring the Higgs coupling to light quarks
• Reconstruction of hadronic decay products of tau leptons with the ATLAS experiment
• Search for the Decay of the Higgs Boson to Charm Quarks with the ATLAS Experiment
• A search for the standard model Higgs boson decaying to charm quarks
• Searches for exclusive Higgs and $Z$ boson decays into $J/\psi \gamma$, $\psi (2S)\gamma$, and ${\rm Y}(nS)\gamma$ at $\sqrt{s}=13$ TeV with the ATLAS detector
• Direct constraint on the Higgs-charm coupling from a search for Higgs boson decays into charm quarks with the ATLAS detector
• Rare exclusive decays of the Z-boson revisited
• Search for rare decays of Z and Higgs bosons to J$/\psi$ and a photon in proton-proton collisions at $\sqrt{s}=$ 13 TeV
• Search for a Higgs boson decaying into gamma* gamma to ll gamma with low dilepton mass in pp collisions at sqrt(s) = 8 TeV
• Searches for exclusive Higgs and $Z$ boson decays into a vector quarkonium state and a photon using $139$ fb${}^{-1}$ of ATLAS $\sqrt{s}=13$ TeV proton$-$proton collision data
• Revisiting the rare $H\to q_i{q}_j$ decays in the Standard Model

Cited by in corpus (2)

• Rare and exclusive few-body decays of the Higgs, Z, W bosons, and the top quark
• Rare few-body decays of the Standard Model Higgs boson