Precision studies of the Higgs boson decay channel H -> ZZ -> 4l with MEKD

Abstract

The importance of the H -> ZZ -> 4l "golden" channel was shown by its major role in the discovery, by the ATLAS and CMS collaborations, of a Higgs-like boson with mass near 125 GeV. We analyze the discrimination power of the matrix element method both for separating the signal from the irreducible ZZ background and for distinguishing various spin and parity hypotheses describing a signal in this channel. We show that the proper treatment of interference effects associated with permutations of identical leptons in the four electron and four muon final states plays an important role in achieving the best sensitivity in measuring the properties of the newly discovered boson. We provide a code, MEKD, that calculates kinematic discriminants based on the full leading order matrix elements and which will aid experimentalists and phenomenologists in their continuing studies of the H -> ZZ -> 4l channel.

arXiv commentMajor revision: added new sections discussing spin/ parity determination and the importance of using the full matrix element for the same flavor final state (involving both pairings of the leptons). Also added new functionality, including the most general couplings of a spin-0 or spin-2 boson to gluons and Zs, to the publicly-available code, MEKD, presented in this paper. 43 pages, 15 figures

References in corpus (51)

• 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
• MadGraph 5 : Going Beyond
• MadGraph/MadEvent v4: The New Web Generation
• FeynRules - Feynman rules made easy
• CalcHEP 3.4 for collider physics within and beyond the Standard Model
• On Kaluza-Klein States from Large Extra Dimensions
• Automatic Generation of Tree Level Helicity Amplitudes
• MCFM for the Tevatron and the LHC
• Spin determination of single-produced resonances at hadron colliders
• On the spin and parity of a single-produced resonance at the LHC
• Standard Model Higgs-Boson Branching Ratios with Uncertainties
• Identifying the Higgs Spin and Parity in Decays to Z Pairs
• LanHEP - a package for the automatic generation of Feynman rules in field theory. Version 3.0
• Prospective Analysis Spin- and CP-sensitive Variables in H -> ZZ -> l_1 l_1 l_2 l_2 with Atlas
• Higgs look-alikes at the LHC
• Aspects of CP violation in the HZZ coupling at the LHC
• CP--odd Correlation in the Decay of Neutral Higgs Boson into $ZZ$, $W^{+}{W}^{-}$, or $t\bar{t}$
• Probing CP Violation Via Higgs Decays to Four Leptons
• The Matrix Element Method at Next-to-Leading Order
• Directly Measuring the Tensor Structure of the Scalar Coupling to Gauge Bosons
• Probing 3-3-1 Models in Diphoton Higgs Boson Decay
• The Matrix Element Method and QCD Radiation
• Measuring Higgs CP and couplings with hadronic event shapes
• Measuring spin and CP from semi-hadronic ZZ decays using jet substructure
• Observation of Z decays to four leptons with the CMS detector at the LHC
• Can the 126 GeV boson be a pseudoscalar?
• The Higgs Mechanism and Loop-induced Decays of a Scalar into Two Z Bosons
• Extending the Higgs Boson Reach at the Upgraded Fermilab Tevatron
• Improving the sensitivity of Higgs boson searches in the golden channel
• Theoretical Basis of Higgs-Spin Analysis in $H\to \gamma \gamma$ and $Z\gamma$ Decays
• Scrutinizing the Higgs Signal and Background in the $2e2\mu$ Golden Channel
• From Lagrangians to Events: Computer Tutorial at the MC4BSM-2012 Workshop
• New Developments in MadGraph/MadEvent
• Single-variable asymmetries for measuring the `Higgs' boson spin and CP properties
• Does the `Higgs' have Spin Zero?
• Is the New Resonance Spin 0 or 2? Taking a Step Forward in the Higgs Boson Discovery
• Energy Spectra and Energy Correlations in the Decay $H\to ZZ\to {\mu }^{+}{\mu }^{-}{\mu }^{+}{\mu }^{-}$
• Telling the spin of the "Higgs boson" at the LHC
• Speedy Higgs boson discovery in decays to tau lepton pairs : h->tau,tau
• Low-mass Higgs decays to four leptons at one loop and beyond
• Spin-analysis of s-channel diphoton resonances at the LHC
• Extending the Matrix Element Method to Next-to-Leading Order
• Comment on the evidence of the Higgs boson at LHC
• Re-weighing the evidence for a Higgs boson in dileptonic W-boson decays
• Spin Determination for Fermiophobic Bosons
• Identification of the 125 GeV Resonance as a Pseudoscalar Quarkonium Meson
• Finding Higgs bosons heavier than 2 m_W in dileptonic W-boson decays
• A 2D fit with background measurement constraints to boost the Higgs to 4l discovery potential at the LHC

Cited by in corpus (39)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Measurement of the properties of a Higgs boson in the four-lepton final state
• Constraints on the spin-parity and anomalous HVV couplings of the Higgs boson in proton collisions at 7 and 8 TeV
• A framework for Higgs characterisation
• Complete Higgs Sector Constraints on Dimension-6 Operators
• Constraining anomalous HVV interactions at proton and lepton colliders
• Constraining Effective Field Theories with Machine Learning
• A Guide to Constraining Effective Field Theories with Machine Learning
• Higher dimensional operators and LHC Higgs data : the role of modified kinematics
• Finding physics signals with event deconstruction
• Beyond Geolocating: Constraining Higher Dimensional Operators in $H\to 4\ell$ with Off-Shell Production and More
• Nonstandard Higgs Couplings from Angular Distributions in $h\to Z{\ell }^{+}{\ell }^{-}$
• Probing the Higgs Couplings to Photons in $h\to 4\ell$ at the LHC
• Associated Production Evidence against Higgs Impostors and Anomalous Couplings
• Geolocating the Higgs Boson Candidate at the LHC
• Extracting Effective Higgs Couplings in the Golden Channel
• The role of interference in unraveling the ZZ-couplings of the newly discovered boson at the LHC
• Inferring the nature of the boson at 125-126 GeV
• A note on Higgs decays into $Z$ boson and $J/\Psi ({\rm Y})$
• Prima Facie Evidence against Spin-Two Higgs Impostors
• 8D Likelihood Effective Higgs Couplings Extraction Framework in the Golden Channel
• Golden Probe of Electroweak Symmetry Breaking
• Golden Probe of the Top Yukawa
• Effective LHC measurements with matrix elements and machine learning
• Diboson Excesses Demystified in Effective Field Theory Approach
• Probing New Physics by the Tail of the Off-shell Higgs in $V_L{V}_L$ Mode
• Lepton-mass effects in the decays $H\to Z{Z}^{\ast }\to {\ell }^{+}{\ell }^{-}{\tau }^{+}{\tau }^{-}$ and $H\to W{W}^{\ast }\to \ell \nu \tau {\nu }_{\tau }$
• Angular asymmetries as a probe for anomalous contributions to HZZ vertex at the LHC
• High Energy WW Scattering at the LHC with the Matrix Element Method
• Probing the Dark Sector through Mono-Z Boson Leptonic Decays
• Decays of a neutral particle with zero spin and arbitrary CP parity into two off-mass-shell Z bosons
• Discoveries far from the Lamppost with Matrix Elements and Ranking
• Measuring the mass, width, and couplings of semi-invisible resonances with the Matrix Element Method
• Disentangling the Spin-Parity of a Resonance via the Gold-Plated Decay Mode
• Efficient Probabilistic Inference in the Quest for Physics Beyond the Standard Model
• Identifying a new particle with jet substructures
• Quarkonium Resonance Model of the 125 GeV Boson
• Quarkonium resonance identified with the 125 GeV boson
• Anomalous $H\to ZZ\to 4\ell$ decay and its interference effects at the LHC