Search for anomalous couplings in the Higgs sector at LEP

Abstract

Anomalous couplings of the Higgs boson are searched for through the processes e+e− → Hγ , e+e− → e+e−H and e+e− → HZ. The mass range 70 GeV < mH < 190 GeV is explored using 602 pb⁻¹ of integrated luminosity collected with the L3 detector at LEP at centre-of-mass energies √s = 189–209 GeV. The Higgs decay channels H → f ̄f, H → γγ , H → Zγ and H → WW^(∗) are considered and no evidence is found for anomalous Higgs production or decay. Limits on the anomalous couplings d, d_B, Δg^Z₁, Δκ_γ and ξ² are derived as well as limits on the H → γγ and H → Zγ decay rates.