arXiv subjects

Rong-Zhi Sun

Publications and source records attributed to Rong-Zhi Sun.

6 recordsLinked to original sources

arXiv2026

Calculation for Electric Dipole Moments of Lepton and Neutron in the N-B-LSSM via the Mass Insertion Approximation

In the N-B-LSSM, we calculate the electric dipole moments (EDMs) of lepton and neutron at the one loop level via the Mass Insertion Approximation (MIA). In the Standard Model (SM), charge parity (CP) violation originates only from the single phase of the Cabibbo-Kobayashi-Maskawa (CKM) matrix, and the predicted EDMs of lepton and neutron are far below the current experimental upper limits. Thus, EDMs serve as sensitive probes for exploring CP-violating phases in new physics. The N-B-LSSM extends the Minimal Supersymmetric Standard Model (MSSM) by introducing right-handed neutrino superfields and additional singlet Higgs superfields, which enriches the particle spectrum and the sources of CP violation. We derive the one loop analytical expressions for lepton and quark EDMs, and reveal their dependence on model parameters such as $g_{YB}$, $θ_{μ_H}$, $θ_{1'}$, $θ_{BB'}$ and $\tanβ$. Numerical analyses demonstrate that EDM measurements strongly constrain the CP-violating parameter space of the N-B-LSSM and reveal the sensitivity of lepton and neutron EDMs to the extended gauge interactions and supersymmetric parameters. This study provides a systematic theoretical tool and numerical reference for exploring CP violation and new physics under the N-B-LSSM.

hep-ph↗

arXiv2026

Pair production of $h$ in the $U(1)_X$SSM

Higgs pair production provides an important probe of the Higgs self-interaction and the Higgs potential structure. We study the lightest neutral Higgs pair production process $gg \to hh$ via gluon fusion at the 14 TeV LHC, in the $U(1)_X$ supersymmetric standard model. As a $U(1)$ extension of the minimal supersymmetric standard model (MSSM), this model introduces new superfields that bring additional one-loop contributions to the production amplitude. We analyze the parameter dependence of the cross section numerically and present contour distributions in two-dimensional parameter planes. The results indicate that the gauge couplings $g_X$ and $g_{YX}$ are the most sensitive parameters, and the model yields sizable new physics corrections under current experimental constraints. This work helps to understand Higgs physics in the $U(1)_X$SSM and guides new physics searches at the high-luminosity LHC.

hep-ph↗

arXiv2026

Higgs Bosons at 95 and 125 GeV in the $U(1)_X$VLFM

We present a systematic analysis of the Higgs signal strengths at 125 GeV and 95 GeV in a non-supersymmetric $U(1)_X$ model with vector-like fermions ($U(1)_X$VLFM). This model extends the SM by introducing an additional $U(1)_X$ gauge symmetry, three right-handed neutrinos, two singlet Higgs fields ($ϕ$ and $S$), and one generation of vector-like quarks and leptons. The scalar fields mix with each other in the neutral CP-even sector, leading to two Higgs-like states around 95 GeV and 125 GeV. A $χ^2$ analysis is performed by combining the Higgs signal strength measurements at 125 GeV from ATLAS and CMS, including the $γγ$, $WW^*$, $ZZ^*$, $b\bar{b}$, and $τ\barτ$ channels, with the 95 GeV excesses observed in the diphoton and $b\bar{b}$ final states reported by CMS and LEP. Our results indicate that the $U(1)_X$VLFM can successfully reproduce the observed signal strengths of the 125 GeV Higgs while simultaneously explaining the 95 GeV excess. The parameters $g_X$, $g_{YX}$, $v_S$, $v_P$, and the new Yukawa couplings play a crucial role in achieving this consistency.

hep-ph↗

arXiv2026

Higgs boson decays $h\rightarrow Z γ$ and $h\rightarrow m_V Z$ in the $U(1)_X$VLFM

We study the Higgs boson decays $h \to Zγ$ and $h \to m_VZ$ in a model with vectorlike fermions and $U(1)_X$ symmetry ($U(1)_X$VLFM), where $m_V$ is a vector meson ($ρ,\ ω,\ ϕ,\ J/ψ,\ Υ$). The exotic Yukawa interactions in this model generate mixing between Standard Model (SM) fermions and vectorlike fermions, and this mixing affects the Higgs boson mass and Higgs couplings. The corrections to the CP-even and CP-odd $hγZ$ couplings come from loop diagrams that involve the new particles, and these corrections have a clear impact on the decay rates of $h\to Zγ$ and $h\to m_VZ$. In suitable regions of the parameter space, the model can produce non-negligible deviations in $Γ_{\rm NP}(h\to Zγ)/Γ_{\rm SM}(h\to Zγ)$ and $Γ_{\rm NP}(h\to m_VZ)/Γ_{\rm SM}(h\to m_V Z)$, providing possible signals of new physics (NP) beyond the SM.

hep-ph↗

arXiv2025

Study of $τ\rightarrow e M^+ M^-$ decays in the N-B-LSSM

Within the framework of the next to the minimal supersymmetric (SUSY) extension of the Standard Model (SM) with a local B-L gauge symmetry (N-B-LSSM), we study lepton flavor violating (LFV) $τ\rightarrow e M^+ M^-$ decays: $τ\rightarrow e π^+π^-$,~$τ\rightarrow e π^+K^-$,~$τ\rightarrow e K^+K^-$. According to the latest experimental data, the influence of different sensitive parameters on the branching ratios is considered. It can be seen from the numerical analysis that the main sensitive parameters and LFV sources are non-diagonal elements corresponding to the initial and final leptons. This work can provide a basis for discovering the existence of new physics (NP).

hep-ph↗

arXiv2025

Lepton flavor violating decays $l_j\rightarrow l_iγ$, $l_j \rightarrow 3l_i$ and $μ\rightarrow e+ q\bar q$ in the N-B-LSSM

The N-B-LSSM is an extension of the minimal supersymmetric standard model (MSSM) with the addition of three singlet new Higgs superfields and right-handed neutrinos, whose local gauge group is $SU(3)_C\times SU(2)_L\times U(1)_Y\times U(1)_{B-L}$. In the N-B-LSSM, we study lepton flavor violating decays $l_j\rightarrow l_iγ$, $l_j \rightarrow 3l_i$ and $μ\rightarrow e+ q\bar q$ $(j=τ,μ,~i=μ,e$ and $i\neq j)$. Based on the current experimental limitations, we carry out detailed parameter scanning and numerical calculations to analyse the effects of different sensitive parameters on lepton flavor violation (LFV) in the N-B-LSSM. The numerical results show that the non-diagonal elements involving the initial and final leptons are main sensitive parameters and LFV sources. This work can provide a strong basis for exploring new physics (NP) beyond the Standard Model (SM).

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