LHC EFT WG meeting

Monday 13 May 2024, 17:00 → 18:30 Europe/Zurich

online

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Zoom recording

17:00 → 17:30 Complete UV Resonances of the Dimension-8 SMEFT Operators

The effective field theory approach parameterizes the low energy behaviors of all possible ultraviolet (UV) theories in a systematic way. One of the most important tasks is thus to find the connection between the effective operators and their UV origins. The redundancy relations among operators make the connection very subtle, hence we proposed the j-basis prescription to illuminate the correspondence between operators and their UV resonances in the bottom-up way. In this work, we work out the dimension-8 j-basis operators in the standard model effective field theory (SMEFT), and find all the 146 (82) tree-level UV resonances along with their couplings up to mass dimension 5 (4). Furthermore, we point out a few subtleties on operator generation via field redefinition and on the UV Lagrangian for generic spin resonances. We also provide a data base storing our results and a \texttt{Mathematica} notebook for extracting those results for the reader's conveinence.

Speaker: Dr Haolin Li (CP3/UCLouvain)

arXiv:2309.15933

17:30 → 18:00 A complete tree-level dictionary between simplified BSM models and SMEFT (d ≤ 7) operators

Finding all possible UV resonances of effective operators is an important task in the bottom-up approach of effective field theory. We present all the tree-level UV resonances for the dimension-5, -6 and -7 operators in the Standard Model effective field theory (SMEFT), and then obtain the correspondence between the UV resonances and the effective operators from the relations among their Wilson coefficients, through the functional matching and operator reduction procedure. This provides a cross-dimension UV/IR dictionary for the SMEFT at tree-level, and the methods used here, especially the on-shell construction of general UV Lagrangian and the systematic reduction of operators, are extendable for UV resonances of d≥8 operators in SMEFT and other EFTs.

Speaker: Xu-Xiang Li (University of Utah)

arXiv:2307.10380