Off-shell single-top-quark production in the Standard Model Effective Field Theory

Neumann, Tobias (0000 0004 1936 7806, grid.62813.3e, Department of Physics, Illinois Institute of Technology, 3101 S. Dearborn St., Chicago, IL, 60616, U.S.A.) (0000 0001 0675 0679, grid.417851.e, Fermilab, P.O. Box 500, Batavia, IL, 60510, U.S.A.) ; Sullivan, Zack (0000 0004 1936 7806, grid.62813.3e, Department of Physics, Illinois Institute of Technology, 3101 S. Dearborn St., Chicago, IL, 60616, U.S.A.)

12 June 2019

Abstract: We present a fully differential and spin-dependent t -channel single-top-quark calculation at next-to-leading order (NLO) in QCD including off-shell effects by using the complex mass scheme in the Standard Model (SM) and in the Standard Model Effective Field Theory (SMEFT). We include all relevant SMEFT operators at 1 / Λ 2 that contribute at NLO in QCD for a fully consistent comparison to the SM at NLO. In addition, we include chirality flipping operators that do not interfere with the SM amplitude and contribute only at 1 / Λ 4 with a massless b -quark. Such higher order effects are usually captured by considering anomalous right-handed Wtb and left-handed Wtb tensor couplings. Despite their formal suppression in the SMEFT, they describe an important class of models for new physics. Our calculation and analysis framework is publicly available in MCFM.


Published in: JHEP 1906 (2019) 022 DOI: 10.1007/JHEP06(2019)022
arXiv: 1903.11023
License: CC-BY-4.0



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