On probing Higgs couplings in H → Ze+e− and e+e−→ ZH

Abstract

Two most popular GUT scenarios, namely, the left–right symmetric model (LRM) and models coming from [Formula: see text] grand unification (effective rank 5 models (ER5M’s)) are considered. Both models forecast existence of the extra neutral gauge boson. Its contributions to the decay of the Higgs boson being an analog of the Standard Model (SM) Higgs boson [Formula: see text] and the process of the associated Higgs production with [Formula: see text] boson (Higgsstrahlung) [Formula: see text] are found. For both processes, deviations from the SM predicted by the LRM prove to be larger than that predicted by the ER5M’s. It is shown that in the case of the decay [Formula: see text] it is impossible to observe these deviations at the condition of the High Luminosity Large Hadron Collider. Investigation of the Higgsstrahlung disclosed that with its help one could make a choice between the SM and the SM extensions under consideration.