Is SMEFT Enough?

Abstract

There are two canonical approaches to treating the Standard Model as an Effective Field Theory (EFT): Standard Model EFT (SMEFT), expressed in the electroweak symmetric phase utilizing the Higgs doublet, and Higgs EFT (HEFT), expressed in the broken phase utilizing the physical Higgs boson and an independent set of Goldstone bosons. HEFT encompasses SMEFT, so understanding whether SMEFT is sufficient motivates identifying UV theories that require HEFT as their low energy limit. This distinction is complicated by field redefinitions that obscure the naive differences between the two EFTs. By reformulating the question in a geometric language, we derive concrete criteria that can be used to distinguish SMEFT from HEFT independent of the chosen field basis. We highlight two cases where perturbative new physics must be matched onto HEFT: (i) the new particles derive all of their mass from electroweak symmetry breaking, and (ii) there are additional sources of electroweak symmetry breaking. Additionally, HEFT has a broader practical application: it can provide a more convergent parametrization when new physics lies near the weak scale. The ubiquity of models requiring HEFT suggests that SMEFT is not enough.

69+28 pages, 6 figures, 33 footnotes. v2: Added minor clarifications, matches JHEP version

References in corpus (4)

• A Higgs-Higgs bound state due to New Physics at a TeV
• Precision Measurements of Higgs Couplings: Implications for New Physics Scales
• Observable Effects of General New Scalar Particles
• Extending the Universal One-Loop Effective Action: Heavy-Light Coefficients

Cited by in corpus (52)

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• Unitarity Violation and the Geometry of Higgs EFTs
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• On the road(s) to the Standard Model
• Non-Decoupling New Particles
• Complete NLO Operators in the Higgs Effective Field Theory
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• An EFT hunter's guide to two-to-two scattering: HEFT and SMEFT on-shell amplitudes
• On-Shell Covariance of Quantum Field Theory Amplitudes
• Neutrino seesaw models at one-loop matching: Discrimination by effective operators
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• Complete NNLO Operator Bases in Higgs Effective Field Theory
• The Anomalous Case of Axion EFTs and Massive Chiral Gauge Fields
• Loop counting matters in SMEFT
• Monolepton production in SMEFT to $\mathcal{O}(1/{\Lambda }^4)$ and beyond
• Effective Field Theories on the Jet Bundle
• Electroweak phase transition in the nearly aligned Higgs effective field theory
• Constructing on-shell operator basis for all masses and spins
• Constructing Generic Effective Field Theory for All Masses and Spins
• Unitarity Bounds on Effective Field Theories at the LHC
• A new Higgs effective field theory and the new no-lose theorem
• Jet Bundle Geometry of Scalar Field Theories
• Strongly first-order electroweak phase transition by relatively heavy additional Higgs bosons
• Primary Observables for Indirect Searches at Colliders
• Effective Field Theories as Lagrange Spaces
• The New Formulation of Higgs Effective Field Theory
• A Strongly First-Order Electroweak Phase Transition from Loryons
• Walls, bubbles and doom -- the cosmology of HEFT
• Effective Field Theory of the Two Higgs Doublet Model
• SMEFT as a slice of HEFT's parameter space
• Form Factors in Higgs Couplings from Physics Beyond the Standard Model
• Anomalies From the Covariant Derivative Expansion
• Dimension-8 SMEFT contact-terms for vector-pair production via on-shell Higgsing
• The Art of Counting: a reappraisal of the HEFT expansion
• Positively Identifying HEFT or SMEFT
• Real Singlet Scalar Benchmarks in the Multi-TeV Resonance Regime
• Renormalising the Field-Space Geometry
• On the EFT of Conformal Symmetry Breaking
• High Energy Vector Boson Scattering in Four-Body Final States to Probe Higgs Cubic, Quartic, and HEFT interactions
• Multi-Higgs Amplitudes Bootstrapped: Dissecting SMEFT and HEFT
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• Non-renormalizable theories and finite formulation of QFT
• Assessing (H)EFT theory errors by pitting EoM against Field Redefinitions
• Aspects of the Electroweak Skyrmion
• From Models to SMEFT and Back?
• Constraints on Loryons in a Two Higgs Doublet Model