The rare decays $h^0\rightarrow Zγ,V Z$ in the NB-LSSM

TL;DR

NB-LSSM extends MSSM by adding three singlet Higgs fields and RH neutrinos, which modify Higgs masses and couplings through mixing and gauge kinetic mixing. The paper analyzes rare Higgs decays $h^0\rightarrow Z\gamma$ and $h^0\rightarrow VZ$ (with $V\in(\phi, J/\psi, \Upsilon(1S), \rho^0, \omega)$) as probes of the loop-induced $h^0Z\gamma$ coupling and potential NP effects parameterized by $\kappa$, $\lambda$, $\lambda_2$ and related soft terms. It derives the effective $h^0Z\gamma$ vertex and the $h^0\rightarrow VZ$ amplitudes (including indirect NP contributions via $h^0Z\gamma$) and performs a numerical scan under current experimental constraints, finding deviations of order $10\%$–$15\%$ from the SM in these channels for plausible NB-LSSM parameter choices. The results highlight the sensitivity of rare Higgs decays to NP in extended gauge/Higgs sectors and provide guidance for future searches at HL-LHC and beyond.

Abstract

This study investigates the Higgs rare decays $h^0\rightarrow Zγ,V Z$ within the next to minimum B-L supersymmetric model(NB-LSSM), where $V$ represents a vector meson $(φ,J/ψ,Υ(1S),ρ^0,ω)$. Compared to the minimal supersymmetric standard model(MSSM), the NB-LSSM introduces three singlet Higgs superfields, which mix with the Higgs doublets and affect the lightest Higgs boson mass and the Higgs couplings. The loop-induced contributions resulting from the effective $h^0Zγ$ coupling can produce new physics(NP) contributions, thereby affecting the theoretical predictions of rare decays significantly through the new parameters such as $κ$, $λ$, $λ_2\cdot\cdot\cdot$. The results of this work can provide a reference for probing NP beyond standard model(SM).

Figures (7)

• Figure 1: The one-loop diagrams for decay $h^{0}\rightarrow Z\gamma$ in the NB-LSSM.
• Figure 2: The major diagrams for decay $h^{0}\rightarrow ZV$ in the NB-LSSM.
• Figure 3: The scatter points for parameters $\lambda,\kappa,\lambda_2,v_S$ and signal strength $\mu_{Z\gamma,ZV}^{gg}$.
• Figure 4: The signal strengths of the Higgs rare decays change with parameters $\tan\beta$ and $\tan\beta'$, where the red lines meet the $3\sigma$ experimental limit of SM-like Higgs boson mass. The red lines in following figures satisfy the same constraints as here.
• Figure 5: The signal strengths of the Higgs rare decays change with parameters $\frac{\lambda*v_S}{\sqrt{2}}$ and $\kappa$.