arXiv subjects

Shu-Min Zhao

Publications and source records attributed to Shu-Min Zhao.

At least 19 recordsLinked to original sources

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.

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arXiv2026

Lepton flavor violating decays $l_j \rightarrow l_i\gamma$ in the $U(1)_X$VLFM

In the $U(1)_X$ vector-like fermion model ($U(1)_X$VLFM), the Standard Model(SM) gauge group is extended with an additional $U(1)_X$ symmetry. Vector-like fermions and right-handed neutrinos are introduced, providing new sources of lepton flavor violation(LFV). In this paper, we perform a detailed study of the LFV decays $l_j \to l_i \gamma$ (with $j = \tau, \mu$; $i = \mu, e$; $i \neq j$) in this model. The numerical results show that, in certain parameter regions, the branching ratios of these processes can become large enough to be probed in future experiments. This work provides important theoretical guidance and constraints for exploring new physics beyond the SM.

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arXiv2026

The Higgs boson decay $h \rightarrow bs$ in the NB-LSSM

Within the framework of the next to minimum B-L supersymmetric model (NB-LSSM), we investigate the flavor transition process $\bar B\rightarrow X_s\gamma$. Building upon this foundation, we further discuss the Higgs decay process $h \to bs$ under the constraint from the $\bar B\rightarrow X_s\gamma$ process. Our study reveals that the branching ratio of $h \to bs$ can significantly deviate from the Standard Model (SM) expectation, depending on the values of the new parameters introduced in the model. This finding highlights the modulation of new physics parameters on the Higgs flavor-violating decay and provides important theoretical grounds for exploring new physics beyond the SM through flavor observables.

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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.

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arXiv2026

Study on the detector energy response of SVOM/GRM

The SVOM mission is specifically designed to for the detection and localization of Gamma-Ray Bursts (GRBs) and subsequent follow-up observations. Among the four telescopes installed on the SVOM satellite, the Gamma-Ray Monitor (GRM) plays a crucial role in capturing the prompt emission of GRBs due to its wide field of view (FOV) and broad energy range. Accurate determination of the detector's energy response is vital for analyzing GRM data, particularly considering the significant impact of the atmospheric albedo effect on this response. This research focuses on deriving the detector's energy response and establishing a calibration database for the GRM, with particular emphasis on investigating the atmospheric albedo effect. The study shows that the contribution of albedo photons to the detector's effective area depends strongly on the orientation of the GRD line of sight (LoS) relative to Earth and on the incident direction of the GRB. When the GRD LoS is anti-Earth oriented, the albedo effect is minimal, with the highest proportion of albedo effective area accounting for approximately 10% of the total effective area. This occurs when the incident angle of the GRB is nearly perpendicular to the LoS. Conversely, if the GRD LoS is not pointing away from Earth and the GRB arrives from angles greater than about 90$^{\circ}$, the albedo component can become predominant, contributing up to around 100% of the total effective area. This is especially pronounced in the 8-20 keV range, where the direct effective area drops to zero due to the large GRB injection angle. Our results show that, it is necessary for GRM to consider the atmospheric albedo effects in detector response, otherwise the spectral and localization analyses will result in biased measurements.

astro-ph.HE↗

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 $g_{YB}$, $\theta_{\mu_H}$, $\theta_{1'}$, $\theta_{BB'}$ and $\tan\beta$. Numerical analyses demonstrate that within a reasonable parameter space, the EDMs of leptons (electron, muon, tau) and the neutron can satisfy the current experimental limitations. This study provides a systematic theoretical tool and numerical reference for exploring CP violation and new physics under the N-B-LSSM.

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arXiv2026

The Higgs boson in the CP-violating NB-LSSM

This study investigates the lightest and second-lightest Higgs bosons at around 95 GeV (which is only a hypothetical scenario) and 125 GeV respectively within the CP-violating next to minimum B-L supersymmetric model(NB-LSSM). In the NB-LSSM, the CP violation in the Higgs potential leads to the mixing mass terms between the CP-even and CP-odd Higgs fields. Thus, one has to consider a $(10 \times 10)$-dimensional mass matrix for the neutral Higgs boson. These potential mixing effects may lead to drastic variations on the neutral Higgs boson masses. Besides, the neutral Higgs bosons predicted in the NB-LSSM may strongly mix with one another, thereby significantly modifying the couplings of the Higgs bosons to the fermions or gauge bosons. It is found that the specific parameters $g_{YB}$, $\tanβ$, $T_κ$, $T_λ, \cdot\cdot\cdot$ and CP-violating phases $θ_{1,2,3,4,6,7,8}$ in the NB-LSSM affect the theoretical predictions on the Higgs boson mass and corresponding signal strengthes significantly. And the theoretical predictions on the signal strengthes of SM-like Higgs decay channels and excess signals at around 95 GeV are fitted well to the observed experimental data.

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arXiv2026

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

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).

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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.

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arXiv2025

Lepton flavor violating decays of Higgs boson in the NB-LSSM

Lepton flavor violation (LFV) represents a clear new physics (NP) signal beyond the standard model (SM). NB-LSSM, the next to minimal supersymmetric extension of the SM with local B-L gauge symmetry, includes three Higgs singlets and three generations of right-handed neutrinos in the basis of MSSM, motivated by the new definition of SM-like Higgs resultly from the introducing of three Higgs singlets which mix with the two Higgs doublets at the tree level in the NB-LSSM. We calculate LFV processes $h\rightarrow l_i l_j$ in the mass eigenstate basis and the electroweak interaction basis separately, and the latter adopts the mass insertion approximation (MIA) method. In the suitable parameter space, we obtain the reasonable numerical results. At the same time, the corresponding constraints from the LFV rare decays $l_j\rightarrow l_iγ$ are considered to analyze the numerical results.

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arXiv2025

Analyzing the magnitude of two loop corrections to the muon magnetic dipole moment in the mass insertion approximation

With the development of muon magnetic dipole moment (MDM) experiments, particularly the high-precision measurements at Fermilab National Accelerator Laboratory (FNAL), experimental data have become increasingly precise. Up to now, the deviation of muon MDM between the experimental data and the standard model prediction is still existing, which may be caused by the new physics contribution. The two loop supersymmetric diagrams can produce important corrections to muon MDM. For many two loop diagrams, we analyse the order of the contribution to select the important two loop diagrams and neglect the tiny one, which is in favor of distinguishing the important two loop diagrams from all the two loop diagrams. In our analysis, we use the mass insertion approximation. There is no rotation matrix during the study and the resulting factors become more intuitive, so the mass insertion method is more suitable for this study of ours.

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arXiv2025

One-loop corrections to the neutrino in the N-B-LSSM

In this paper, we study one-loop corrections to the neutrino mass matrix in the N-B-LSSM. We obtain the N-B-LSSM from the $U(1)$ extension of the minimal supersymmetric standard model(MSSM). By adding three generation right-handed neutrino superfields and three Higgs singlets, the model generates tiny neutrino masses at the tree level through the first type seesaw mechanism. However, one-loop corrections are essential for understanding neutrino masses and mixing angles. In our calculations, the one-loop corrections contribute approximately 10\% to the total result. We calculate the neutrino mass variance and mixing angle from both normal order neutrino mass spectrum and inverse order neutrino mass spectrum. Crucially, these corrections are 3-5 times larger than current experimental uncertainties. And they have implications for future neutrino oscillation experiments. This study provides new theoretical support for exploring the mechanism of neutrino mass generation in the supersymmetric model and provides clues for exploring new physics beyond the Standard Model (SM).

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arXiv2025

A 95 GeV Higgs Boson in the $U(1)_X$SSM

The CMS and ATLAS Collaborations have recently reported their findings based on the comprehensive run 2 dataset, detailing their searches for a light Higgs boson with a mass of approximately 95 GeV. We investigate the excesses observed in the $γγ$ and $b{\bar b}$ data at approximately 95 GeV in the $U(1)_X$ extension of the minimal supersymmetric standard model ($U(1)_X$SSM). Additionally, it also mixes with the SM-like Higgs boson. Research indicates that, in this model, identifying the mixture of the singlet Higgs states as the lightest Higgs boson holds tremendous potential for explaining the excess observed at approximately 95 GeV. In our calculations, we maintain the masses of the lightest and next-to-lightest Higgs bosons at approximately 95 GeV and 125 GeV, respectively. The study finds that the theoretical predictions for the signal strengths $μ(h_{95})_{γγ}$ and $μ(h_{95})_{b{\bar b}}$ in the $U(1)_X$SSM align well with the excesses observed by CMS.

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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).

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arXiv2025

Neutrino transition magnetic moment in the $U(1)_X$SSM

This paper investigates the neutrino transition magnetic moment in the $U(1)_X$SSM. $U(1)_X$SSM is the $U(1)$ extension of Minimal Supersymmetric Standard Model (MSSM) and its local gauge group is extended to $SU(3)_C\times SU(2)_L \times U(1)_Y\times U(1)_X$. To obtain this model, three singlet new Higgs superfields and right-handed neutrinos are added to the MSSM, which can explain the results of neutrino oscillation experiments. The neutrino transition magnetic moment is induced by electroweak radiative corrections. By applying effective Lagrangian method and on-shell scheme, we study the associated Feynman diagrams and the transition magnetic moment of neutrinos in the model. We fit experimental data for neutrino mass variances and mixing angle. Based on the range of data selection, the influences of different sensitive parameters on the results are analysed. The numerical analysis shows that many parameters have an effect on the neutrino transition moment, such as $g_X$, $M_2$, $λ_H$ and $g_{YX}$. For our numerical results, the order of magnitude of $μ_{ij}^M/μ_B$ is around $10^{-20}$ $\sim$ $10^{-19}$.

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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arXiv2025

Study some two loop contribution to muon anomalous MDM in the N-B-LSSM

It is well known that the muon magnetic dipole moment (MDM) has close relation with the new physics (NP) in the development of the Standard Model (SM). Combined with the Fermilab National Accelerator Laboratory (FNAL) and the Brookhaven National Laboratory (BNL) E821 result, the departure from the SM prediction is about 5.0 $σ$. We study the electroweak corrections from several type two-loop SUSY diagrams and the virtual SUSY particles include chargino, neutralino, scalar lepton and scalar neutrino. Based on the latest experimental constraints, we study the {muon anomalous MDM} under the next to the minimal supersymmetric extension of the SM with local B-L gauge symmetry (N-B-LSSM). The abundant numerical results verify that $\tanβ,~T_e,~M^2_L,~M^2_e,~M_{BB'}$ play an important role in {muon anomalous MDM}. $M^2_e,~\tanβ$ and $T_e$ are sensitive parameters to {muon anomalous MDM}. From the data obtained in all the figures of the numerical results, most of the values of $a_μ^{NBL}$ are in 2$σ$ interval, which can compensate the departure between the experiment data and the SM prediction.

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arXiv2024

Right-handed neutrino dark matter in $U(1)_X$SSM

There is strong evidence for the existence of dark matter in a number of current experiments. We study dark matter using the $U(1)_X$SSM obtained from the $U(1)_X$ extension of the minimal supersymmetric standard model (MSSM). In the $U(1)_X$SSM, we use the right-handed neutrino as a dark matter candidate, whose lightest mass eigenstate has cold dark matter features. In this paper, the relic density of right-handed neutrino as dark matter is investigated. For dark matter scattering, both spin-independent and spin-dependent cross sections are studied. In the final numerical results obtained, some parameter spaces can satisfy the constraints of the relic density and dark matter direct detection experiments.

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