English

Top quark decay at next-to-leading order in the Standard Model Effective Field Theory

High Energy Physics - Phenomenology 2019-12-23 v2

Abstract

We consider top quark decay in the Standard Model Effective Field Theory (SMEFT). We present a calculation of the total decay width and the WW-boson helicity fractions at next-to-leading order (NLO) in SMEFT. Our result includes the complete set of contributing four-fermion operators in addition to QCD dipole operators and bottom-mass suppressed effects. We show that operators that first appear at NLO in the SMEFT can be bounded by the current data as well as future data from both a high-luminosity LHC and a potential e+ee^+e^- collider, demonstrating the importance of going beyond leading order when studying the SMEFT. We discuss technical aspects of our calculation that we believe will be useful in future higher-order studies of the SMEFT, in particular the treatment of γ5\gamma_5 in loop diagrams.

Keywords

Cite

@article{arxiv.1907.00997,
  title  = {Top quark decay at next-to-leading order in the Standard Model Effective Field Theory},
  author = {Radja Boughezal and Chien-Yi Chen and Frank Petriello and Daniel Wiegand},
  journal= {arXiv preprint arXiv:1907.00997},
  year   = {2019}
}

Comments

26 pages, 7 figures; fixed Latex formatting issue affecting equations A.35-A.37