Higgs boson decays h→ Z γ and h→ m_V Z in the U(1)_X SSM

We present a detailed analysis of the Higgs boson decays h→ Z γ and h→ m_V Z in the U(1)_X SSM, with m_V denoting one of the mesons ( ω ,ρ ,ϕ ,J/ψ,Υ ). Using the effective Lagrangian method, we calculate the effective constants C_γ Z (CP-even) and C̃_γ Z (CP-odd) for the vertex h γ Z , which are corrected by the new particle loop diagrams. Numerically, the ratio Γ_U(1)_X(h→ Z γ )/Γ_SM(h→ Z γ ) is between 1.02 and 1.35. For the vector mesons ω ,ρ ,ϕ and J/ψ , the ratios Γ_U(1)_X(h→ m_V Z )/Γ_SM(h→ m_V Z) are mainly distributed in the range of (1.01–1.45). When m_V represents Υ , the ratio Γ_U(1)_X(h→Υ Z )/Γ_SM(h→Υ Z) is mostly located in the range of (1.002–1.30). The aim of this work is to provide a reference for probing the U(1)_X SSM model via the Higgs decays h→ Z γ and h→ m_V Z .