Measurement of the $VH,H\to \tau \tau$ process with the ATLAS detector at 13 TeV

Abstract

A measurement of the Standard Model Higgs boson produced in association with a $W$ or $Z$ boson and decaying into a pair of $\tau$-leptons is presented. This search is based on proton-proton collision data collected at $\sqrt{s}=13$ TeV by the ATLAS experiment at the LHC corresponding to an integrated luminosity of 140 fb${}^{-1}$. For the Higgs boson candidate, only final states with at least one $\tau$-lepton decaying hadronically ($\tau \to \mathrm{hadrons}+{\nu }_{\tau }$) are considered. For the vector bosons, only leptonic decay channels are considered: $Z\to \ell \ell$ and $W\to \ell {\nu }_{\ell }$, with $\ell =e,\mu$. An excess of events over the expected background is found with an observed (expected) significance of 4.2 (3.6) standard deviations, providing evidence of the Higgs boson produced in association with a vector boson and decaying into a pair of $\tau$-leptons. The ratio of the measured cross-section to the Standard Model prediction is ${\mu }_{\text{VH}}^{\tau \tau }=1.28{}_{-0.29}^{+0.30}(stat.){}_{-0.21}^{+0.25}(syst.)$. This result represents the most accurate measurement of the \vh process achieved to date.

arXiv comment46 pages in total, author list starting on page 30, 5 figures, 6 tables. B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2018-20/

References in corpus (46)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• The anti-k_t jet clustering algorithm
• An Introduction to PYTHIA 8.2
• 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
• Herwig++ Physics and Manual
• Parton distributions with LHC data
• The ATLAS Simulation Infrastructure
• PDF4LHC recommendations for LHC Run II
• Parton distributions in the LHC era: MMHT 2014 PDFs
• Herwig 7.0 / Herwig++ 3.0 Release Note
• A Positive-Weight Next-to-Leading-Order Monte Carlo for Heavy Flavour Hadroproduction
• Event Generation with Sherpa 2.2
• Performance of the ATLAS Trigger System in 2015
• Muon reconstruction performance of the ATLAS detector in proton--proton collision data at $\sqrt{s}$=13 TeV
• 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
• NNLO QCD corrections to the Higgs-strahlung processes at hadron colliders
• ATLAS $b$-jet identification performance and efficiency measurement with $t\bar{t}$ events in $pp$ collisions at $\sqrt{s}=13$ TeV
• 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
• Electroweak Radiative Corrections to Associated WH and ZH Production at Hadron Colliders
• Observation of Higgs boson decay to bottom quarks
• ATLAS data quality operations and performance for 2015-2018 data-taking
• Performance of missing transverse momentum reconstruction with the ATLAS detector using proton-proton collisions at $\sqrt{s}$ = 13 TeV
• 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
• Observation of $H\to b\bar{b}$ decays and $VH$ production with the ATLAS detector
• Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector
• Higgs boson production in association with top quarks in the POWHEG BOX
• Matching Tree-Level Matrix Elements with Interleaved Showers
• Observation of the Higgs boson decay to a pair of tau leptons with the CMS detector
• vh@nnlo - Higgs Strahlung at hadron colliders
• Top-Quark Mediated Effects in Hadronic Higgs-Strahlung
• A New Mass Reconstruction Technique for Resonances Decaying to di-tau
• HAWK 2.0: A Monte Carlo program for Higgs production in vector-boson fusion and Higgs strahlung at hadron colliders
• ATLAS flavour-tagging algorithms for the LHC Run 2 $pp$ collision dataset
• Measurement of $W^{\pm }Z$ production cross sections and gauge boson polarisation in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector
• Guide to transverse projections and mass-constraining variables
• 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
• Identification and rejection of pile-up jets at high pseudorapidity with the ATLAS detector
• The ATLAS Inner Detector Trigger performance in pp collisions at 13 TeV during LHC Run 2
• Performance of the ATLAS Level-1 topological trigger in Run 2