Search for anomalous couplings in the Higgs sector at LEP

Abstract

We search for a Higgs particle with anomalous couplings in the e⁺e⁻→Hγ, e⁺e⁻→HZ and e⁺e⁻→He⁺e⁻ processes with the L3 detector at LEP. We explore the mass range 70 GeV < m_H < 170 GeV using 176 pb⁻¹ of integrated luminosity at a center-of-mass energy of √ s = 189 GeV. The Higgs decays H→bb̅, H→γγ and H→Zγ are considered in the analysis. No evidence for anomalous Higgs production is found. This is interpreted in terms of limits on the anomalous couplings d, d_B, Δg₁^Z and ΔΚ_γ. Limits on the Γ(H→γγ) and Γ(H→Zγ) partial widths in the explored Higgs mass range are also obtained.