On interference and non-interference in the SMEFT

Abstract

We discuss interference in the limit ${\hat{m}}_W^2/s\to 0$ in the Standard Model Effective Field Theory (SMEFT). Dimension six operators that contribute to $\bar{\psi }\psi \to {\overline{{\psi }^{\prime }}}_1{\psi }_2^{\prime }{\overline{{\psi }^{\prime }}}_3{\psi }_4^{\prime }$ scattering events can experience a suppression of interference effects with the Standard Model in this limit. This occurs for subsets of phase space in some helicity configurations. We show that approximating these scattering events by $2\to 2$ on-shell scattering results for intermediate unstable gauge bosons, and using the narrow width approximation, can miss interference terms present in the full phase space. Such interference terms can be uncovered using off-shell calculations as we explicitly show and calculate. We also study the commutation relation between the SMEFT expansion and the narrow width approximation, and discuss some phenomenological implications of these results.

19 pages, 3 figures. Updated to published JHEP version

References in corpus (10)

• The SMEFTsim package, theory and tools
• Precision Measurements of Higgs Couplings: Implications for New Physics Scales
• $W^{\pm }Z$ production at the LHC: fiducial cross sections and distributions in NNLO QCD
• Model-independent precision constraints on dimension-6 operators
• Helicity Selection Rules and Non-Interference for BSM Amplitudes
• Anomalous Triple Gauge Couplings in the Effective Field Theory Approach at the LHC
• Diboson Interference Resurrection
• Novel measurements of anomalous triple gauge couplings for the LHC
• An NLO QCD effective field theory analysis of $W_{}^{+}{W}_{}^{-}$ production at the LHC including fermionic operators
• Scheming in the SMEFT... and a reparameterization invariance!

Cited by in corpus (9)

• The Standard Model as an Effective Field Theory
• The Gauge-Higgs Legacy of the LHC Run II
• Structure of two-loop SMEFT anomalous dimensions via on-shell methods
• Field redefinitions in effective theories at higher orders
• Precision diboson measurements at hadron colliders
• A sensitivity study of VBS and diboson WW to dimension-6 EFT operators at the LHC
• Interference Resurrection of the $\tau$ Dipole through Quantum Tomography
• Adding Pseudo-Observables to the Four-Lepton Experimentalist's Toolbox
• Polarized-boson pairs at NLO in the SMEFT