General form of effective operators from hidden sectors

Abstract

We perform a model-independent analysis of the dimension-six terms that are generated in the low energy effective theory when a hidden sector that communicates with the Standard Model (SM) through a specific portal operator is integrated out. We work within the Standard Model Effective Field Theory (SMEFT) framework and consider the Higgs, neutrino and hypercharge portals. We find that, for each portal, the forms of the leading dimension-six terms in the low-energy effective theory are fixed and independent of the dynamics in the hidden sector. For the Higgs portal, we find that two independent dimension-six terms are generated, one of which has a sign that, under certain conditions, is fixed by the requirement that the dynamics in the hidden sector be causal and unitary. In the case of the neutrino portal, for a single generation of SM fermions and assuming that the hidden sector does not violate lepton number, a unique dimension-six term is generated, which corresponds to a specific linear combination of operators in the Warsaw basis. For the hypercharge portal, a unique dimension-six term is generated, which again corresponds to a specific linear combination of operators in the Warsaw basis. For both the neutrino and hypercharge portals, under certain conditions, the signs of these terms are fixed by the requirement that the hidden sector be causal and unitary. We perform a global fit of these dimension-six terms to electroweak precision observables, Higgs measurements and diboson production data and determine the current bounds on their coefficients.

v2: 27 pages, 7 figures and 1 table; matches published version

References in corpus (26)

• Dimension-Six Terms in the Standard Model Lagrangian
• Secluded WIMP Dark Matter
• Precision Electroweak Measurements on the Z Resonance
• Gauge Singlet Scalars as Cold Dark Matter
• The Minimal Model of Nonbaryonic Dark Matter: A Singlet Scalar
• The Strongly-Interacting Light Higgs
• Renormalization Group Evolution of the Standard Model Dimension Six Operators III: Gauge Coupling Dependence and Phenomenology
• Electroweak Measurements in Electron-Positron Collisions at W-Boson-Pair Energies at LEP
• The Twin Higgs: Natural Electroweak Breaking from Mirror Symmetry
• Renormalization Group Evolution of the Standard Model Dimension Six Operators II: Yukawa Dependence
• Renormalization Group Evolution of the Standard Model Dimension Six Operators I: Formalism and lambda Dependence
• Electroweak symmetry breaking after LEP1 and LEP2
• Two-component spinor techniques and Feynman rules for quantum field theory and supersymmetry
• Effective description of general extensions of the Standard Model: the complete tree-level dictionary
• Thermal Relics in Hidden Sectors
• Top, Higgs, Diboson and Electroweak Fit to the Standard Model Effective Field Theory
• Theoretical Constraints on the Higgs Effective Couplings
• Consistency of the Standard Model Effective Field Theory
• Putting SMEFT Fits to Work
• $\text{HEPfit}$: a Code for the Combination of Indirect and Direct Constraints on High Energy Physics Models
• Convex Geometry Perspective to the (Standard Model) Effective Field Theory Space
• Twin Baryogenesis
• Effective theories of universal theories
• The Hyperbolic Higgs
• Singlet Scalar Top Partners from Accidental Supersymmetry
• Twin Cogenesis