Dilepton production in the SMEFT at $\mathcal{O}(1/{\Lambda }^4)$

Abstract

We study the inclusion of $\mathcal{O}(1/{\Lambda }^4)$ effects in the Standard Model Effective Field Theory in fits to the current Drell-Yan data at the LHC. Our analysis includes the full set of dimension-6 and dimension-8 operators contributing to the dilepton process, and is performed to next-to-leading-order in the QCD coupling constant at both $\mathcal{O}(1/{\Lambda }^2)$ and $\mathcal{O}(1/{\Lambda }^4)$. We find that the inclusion of dimension-6 squared terms and certain dimension-8 operators has significant effects on fits to the current data. Neglecting them leads to bounds on dimension-6 operators off by large factors. We find that dimension-8 four-fermion operators can already be probed to the several-TeV level by LHC results, and that their inclusion significantly changes the limits found for dimension-6 operators. We discuss which dimension-8 operators should be included in fits to the LHC data. Only a manageable subset of two-derivative dimension-8 four-fermion operators need to be included at this stage given current LHC uncertainties.

38 pages, 10 figures, 8 tables. Corrected a few typos in Appendix A

References in corpus (6)

• Extending the Standard Model Effective Field Theory with the Complete Set of Dimension-7 Operators
• Complete Higgs Sector Constraints on Dimension-6 Operators
• Compilation of low-energy constraints on 4-fermion operators in the SMEFT
• Electroweak corrections to hadronic production of W bosons at large transverse momenta
• Precision Electroweak Analysis after the Higgs Boson Discovery
• Four-lepton Z-boson decay constraints on the SMEFT