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Deutsch Intern
  • [Translate to Englisch:] Seminar Elementarteilchenphysik
Theoretical Physics II

MSc. Jannis Lang

Karlsruher Institut für Technologie

T a l k : 15. December 2022

Effective field theory descriptions of Higgs boson pair production at NLO QCD

Abstract

Higgs pair production depends on the trilinear Higgs coupling already at LO in the SM, which makes it the prime channel to study the structure of the Higgs potential. For a general BSM scenario, however, a variation of one parameter of the SM does not provide the complete picture. Hence, the framework of bottom-up effective field theories (EFTs) is applied for the parameterisation of a generic (non-resonant) modification of the process.

In this talk, I introduce the concept for the linear (SMEFT) and non-linear (HEFT) EFT extensions of the SM and present the relevant contributions to gg → hh that are implemented in the POWHEG BOX process ggHH SMEFT. Subsequently, I demonstrate results at NLO QCD in SMEFT and HEFT, where the former is realized with several truncation options using contributions of dimension 6 operators. I discuss uncertainties due to the truncation of the SMEFT expansion using the truncation options as a proxy and point out the pitfalls in the translation of the two EFT pictures. Finally, I review power counting rules in SMEFT and give an outlook on the inclusion of subleading contributions.