A1b: Higgs boson physics with higher order QCD corrections within the Higgs Effective Theory

Principal investigators
Prof. Kirill Melnikov Karlsruhe Institute of Technology
Prof. Robert Harlander RWTH Aachen University

Subject

Observed properties of the discovered Higgs boson seem to imply the simplest possible realization of the electroweak symmetry breaking mechanism, in perfect agreement with the Standard Model. This simplicity is puzzling and warrants a detailed exploration of this particle, especially its couplings to matter and gauge fields. A consistent framework to describe Higgs sector of the Standard Model is provided by “Standard Model Effective Field Theory'', where effects of physics beyond the Standard Model (BSM) are introduced by adding higher-dimensional operators to the Standard Model Lagrangian. The (Wilson) coefficients of these higher-dimensional operators need to be determined from experimental measurements. Since the expected deviations from the SM are small, their unambiguous determination requires a precise description of the production cross sections and kinematic distributions for a large number of processes with the Higgs boson in the final state. In particular, a potentially non-trivial interplay between higher-order perturbative effects, that are known to be quite large for many observables in Higgs physics, and the anomalous couplings needs to be addressed and understood.

Research Topics

  1. Standard Model Effective Theory: QCD renormalization of the relevant effective operators
  2. Higgs coupling to vector bosons: associated $VH$ and weak boson fusion production with NNLO QCD corrections and higher-dimensional operators
  3. Yukawa couplings of light and heavy quarks: $q \bar q \to H$ and $gg \to H$ through NNLO QCD and the determination of light quarks Yukawa coupling
  4. $H+j$ production with higher-order corrections, quark mass effects, higher-dimensional operators and Higgs decays