arXiv subjects

Yuanfang Yue

Publications and source records attributed to Yuanfang Yue.

16 recordsLinked to original sources

arXiv2026

EasyScan_HEP 2: LLM-Agent Parameter-Scan Workflows in High Energy Physics

Large-language-model (LLM) agents are beginning to reshape the preparation and steering of computational workflows in high-energy physics phenomenology. To accommodate this change, we upgrade EasyScan_HEP to make the construction of parameter-scan configuration files more accessible to LLM-agent assistance. EasyScan_HEP 2 exposes command-line and machine-readable interfaces for LLM-agent workflows, allowing an assistant to translate natural language requests into an explicit .ini configuration that defines the scan method, external-program workflow, constraints, and outputs. The resulting configuration can be inspected through a local Web interface. The framework also supports LLM-agent-guided extension to new scan methods, as illustrated by the integration of BESTFIT, EMCEE, and DYNESTY. In this way, EasyScan_HEP 2 adapts parameter-scan workflows to LLM-agent use while preserving reproducibility, transparency, and user control.

hep-ph↗

arXiv2026

Viability of Sub-TeV Higgsino Dark Matter with Nearly Mass-Degenerate Sleptons

The higgsino-like neutralino is a compelling dark matter candidate motivated by both cosmology and naturalness considerations. While a pure higgsino typically requires a mass of around $1.1~\mathrm{TeV}$ to satisfy the observed thermal relic abundance, the presence of light sleptons can significantly alter this requirement. In this work, we revisit higgsino dark matter within the Minimal Supersymmetric Standard Model (MSSM), focusing on scenarios with slepton coannihilation. We find that the presence of nearly mass-degenerate sleptons in the thermal bath can allow the higgsino mass to be as light as $\sim 400$ GeV while satisfying relic density constraints. We explicitly contrast the impact of recent direct detection updates: the LZ-2022 limits raise this lower bound to approximately $450~\mathrm{GeV}$, while the stringent LZ-2024 constraints further shift the viable mass floor to $\sim 500~\mathrm{GeV}$. Crucially, we demonstrate that the direct detection sensitivity is strongly dependent on the relative signs of the gaugino mass parameters $M_1$ and $M_2$. We find that scenarios with $M_1, M_2 > 0$ are fully excluded by LZ-2024. Conversely, configurations with opposite signs ($M_1/M_2 < 0$) remain broadly viable, as destructive interference in the neutralino-Higgs coupling efficiently suppresses the spin-independent cross section. Finally, we delineate the remaining viable parameter space for both the opposite-sign cases and the specific configurations with negative $M_1$ and $M_2$.

hep-ph↗

arXiv2025

Attractive features of Higgsino Dark Matter in the Next-to-Minimal Supersymmetric Standard Model

In the Higgsino dark matter (DM) scenario of the Minimal Supersymmetric Model (MSSM), the mixing of Gaugino and Higgsino influences the mass splitting between neutralinos predominantly composed of Higgsino and introduces coupling between the DM and Higgs bosons. These effects modify the DM-nucleon scattering cross-section, causing conflicts with the latest direct detection results from LZ experiments for both substantial and minute mixings. Consequently, the experimental measurement of DM relic density necessitates the Higgsino DM mass to be approximately 1.1 TeV. We discovered that in the Higgsino DM scenario of the Next-to-Minimal Supersymmetric Model (NMSSM), the mixing of Higgsino and Singlino introduces analogous effects, with a crucial distinction being that the current LZ experiment permits significant mixing between Singlino and Higgsino. This pronounced mixing effect effectively attenuates the interactions between Higgsino-dominated neutralinos and standard model particles, enabling DM masses exceeding roughly 670 GeV to achieve the correct relic abundance. Through analytical formulas and numerical results, we elucidated these characteristics which were not observed before. Our research reveals that in the NMSSM, when comprehensively examining the mixing effects of Higgsino, Gaugino, and Singlino, the properties of Higgsino DM become markedly more intricate compared to the MSSM predictions.

hep-ph↗

arXiv2025

Antiferromagnetic two-dimensional transition-metal nitride Co$_2$N$_2$ layer with high N$\rm \acute{\textbf e}$el temperature and Dirac fermions

Two-dimensional (2D) transition metal nitrides have a wide prospect of applications in the fields of physics, chemistry, materials, etc. However, 2D transition metal nitrides with strong magnetism, especially high N$\rm \acute{e}$el temperature, are very scarce. Based on the first-principles calculations within the framework of density functional theory, we design two 2D transition-metal nitrides \textit{M}$_2$N$_2$ (\textit{M} = Ti, Co), in which the transition metal atoms and the N atoms form a 2D layer with a wrinkled structure. The structural stability is demonstrated by the cohesive energy, formation energy, elastic constants, phonon spectra and molecular dynamics simulations. Elastic moduli calculations reveal that the mechanical properties of the two structures are anisotropic. Spin-polarized calculations show that Ti$_2$N$_2$ is a 2D ferromagnetic material while Co$_2$N$_2$ is a 2D antiferromagnetic semimetal with a Dirac point at Fermi level. Furthermore, by solveing the Heisenberg model by Monte Carlo method, we discover that the 2D Co$_2$N$_2$ layer is a high-temperature antiferromagnetic material and the N$\rm \acute{e}$el temperature is up to 474 K. Therefore, our findings provide a rare antiferromagnetic 2D material with both high critical temperature and Dirac Fermions.

cond-mat.mtrl-sci↗

arXiv2025

Ferroelectricity originating from polar moiety flipping

A wide variety of applications has inspired great interest in designing new materials and investigating fundamental physics in the ferroelectric field. In the concept of ferroelectricity, the spontaneous polarization is traditionally considered a core property, but we find that the `spontaneous' seems unnecessary. Based on this understanding, we suggest a new type of ferroelectric materials, in which the polar atomic moiety is incorporated to realize the electric polarization and the polar atomic moiety flipping corresponds to the reversal of electric polarization. Lead hydroxyapatite Pb$_{10}$(PO$_4$)$_6$(OH)$_2$ containing polar OH moieties is taken as an example to illustrate our idea, in which the OH moiety flipping result in the reversal of electric polarization. The mechanism of ferroelectricity reported herein distinctly differs from those of the displacive type, disorder-order type, and interlayer sliding type ferroelectric materials in the previous studies.

cond-mat.mtrl-sci↗

arXiv2023

Impact of recent measurement of $(g-2)_μ$, LHC search for supersymmetry, and LZ experiment on Minimal Supersymmetric Standard Model

Motivated by the recent measurement of muon anomalous magnetic moment at Fermilab, the rapid progress of the LHC search for supersymmetry, and the significantly improved sensitivities of dark matter direct detection experiments, we studied their impacts on the Minimal Supersymmetric Standard Model (MSSM). We conclude that higgsino mass should be larger than about $500~{\rm GeV}$ for $M_1 < 0 $ and $630~{\rm GeV}$ for $M_1 > 100~{\rm GeV}$, where $M_1$ denotes the bino mass. These improved bounds imply a tuning of ${\cal{O}}(1\%)$ to predict the $Z$-boson mass and simultaneously worsen the naturalness of the $Z$- and $h$-mediated resonant annihilations to achieve the measured dark matter density. We also conclude that the LHC restrictions have set lower bounds on the sparticle mass spectra: $ m_{\tildeχ_1^0} \gtrsim 210~{\rm GeV}$, $m_{\tildeχ_2^0}, m_{\tildeχ_1^\pm} \gtrsim 235~{\rm GeV}$, $m_{\tildeχ_3^0} \gtrsim 515~{\rm GeV}$, $m_{\tildeχ_4^0} \gtrsim 525~{\rm GeV}$, $m_{\tildeχ_2^\pm} \gtrsim 530~{\rm GeV}$, $m_{\tildeν_μ} \gtrsim 235~{\rm GeV}$, $ m_{\tildeμ_1} \gtrsim 215~{\rm GeV}$, and $m_{\tildeμ_2} \gtrsim 250~{\rm GeV}$, where $\tildeχ_{2}^0$ and $\tildeχ_1^\pm$ are wino-dominated when they are lighter than about $500~{\rm GeV}$. These bounds are far beyond the reach of the LEP experiments in searching for supersymmetry and have not been acquired before. In addition, we illuminate how some parameter spaces of the MSSM have been tested at the LHC and provide five scenarios in which the theory coincides with the LHC restrictions. Once the muon g-2 anomaly is confirmed to originate from supersymmetry, this research may serve as a guide to explore the characteristics of the MSSM in future experiments.

hep-ph↗

arXiv2023

Electron and Muon Anomalous Magnetic Moment in the $\mathbb{Z}_3$-NMSSM

Inspired by the recent measurements of the muon and electron anomalous magnetic moments, the rapid progress of the LHC search for supersymmetry, and the significantly improved sensitivities of dark matter direct detection experiments, we studied the supersymmetric contribution to the electron \texorpdfstring{$g-2$}{}, $a_e^{\rm SUSY}$, in the Next-to-Minimal Supersymmetric Standard Model with a discrete $\mathbb{Z}_3$ symmetry. We concluded that $a_e^{\rm SUSY}$ was mainly correlated with $a_μ^{\rm SUSY}$ by the formula $a_e^{\rm SUSY}/m_e^2 \simeq a_μ^{\rm SUSY}/m_μ^2$, and significant violations of this correlation might occur only in rare cases. As a result, $a_e^{\rm SUSY}$ was typically around $5 \times 10^{-14}$ when $a_μ^{\rm SUSY} \simeq 2.5 \times 10^{-9}$. We also concluded that the dark matter direct detection and LHC experiments played crucial roles in determining the maximum reach of $a_e^{\rm SUSY}$. Concretely, $a_e^{\rm SUSY}$ might be around $3 \times 10^{-13}$ in the optimum cases if one used the XENON-1T experiment to limit the supersymmetry parameter space. This prediction, however, was reduced to $1.5 \times 10^{-13}$ after implementing the LZ restrictions and $1.0 \times 10^{-13}$ when further considering the LHC restrictions.

hep-ph↗

arXiv2023

Status of the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model

With the rapid progress of dark matter direct detection experiments, the attractiveness of the popular bino-dominated dark matter in economical supersymmetric theories is fading. As an alternative, the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model (NMSSM) is paying due attention. This scenario has the following distinct characteristics: free from the tadpole problem and the domain-wall problem of the NMSSM with a $Z_3$-symmetry, predicting more stable vacuum states than the $Z_3$-NMSSM, capable of forming an economical secluded dark matter sector to yield the dark matter experimental results naturally, and readily weaken the restrictions from the LHC search for SUSY. Consequently, it can explain the muon g-2 anomaly in broad parameter space that agrees with various experimental results while simultaneously breaking the electroweak symmetry naturally. In this study, we show in detail how the scenario coincides with the experiments, such as the SUSY search at the LHC, the dark matter search by the LZ experiment, and the improved measurement of the muon g-2. We provide a simple and clear picture of the physics inherent in the general NMSSM.

hep-ph↗

arXiv2022

Impact of recent $(g-2)_μ$ measurement on the light CP-even Higgs scenario in general Next-to-Minimal Supersymmetric Standard Model

The General Next-to-Minimal Supersymmetric Standard Model (GNMSSM) is an attractive theory that is free from the tadpole problem and the domain-wall problem of $Z_3$-NMSSM, and can form an economic secluded dark matter (DM) sector to naturally predict the DM experimental results. It also provides mechanisms to easily and significantly weaken the constraints from the LHC search for supersymmetric particles. These characteristics enable the theory to explain the recently measured muon anomalous magnetic moment, $(g-2)_μ$, in a broad parameter space that is consistent with all experimental results and at same time keeps the electroweak symmetry breaking natural. This work focuses on a popular scenario of the GNMSSM in which the next-to-lightest CP-even Higgs boson corresponds to the scalar discovered at the Large Hadron Collider (LHC). Both analytic formulae and a sophisticated numerical study show that in order to predict the scenario without significant tunings of relevant parameters, the Higgsino mass $μ_{tot} \lesssim 500~{\rm GeV}$ and $\tan β\lesssim 30$ are preferred. This character, if combined with the requirement to account for the $(g-2)_μ$ anomaly, will entail some light sparticles and make the LHC constraints very tight. As a result, this scenario can explain the muon anomalous magnetic moment in very narrow corners of its parameter space.

hep-ph↗

arXiv2021

Singlino-dominated dark matter in general NMSSM

The general Next-to-Minimal Supersymmetric Standard Model (NMSSM) describes the singlino-dominated dark-matter (DM) property by four independent parameters: singlet-doublet Higgs coupling coefficient $λ$, Higgsino mass $μ_{tot}$, DM mass $m_{\tildeχ_1^0}$, and singlet Higgs self-coupling coefficient $κ$. The first three parameters strongly influence the DM-nucleon scattering rate, while $κ$ usually affects the scattering only slightly. This characteristic implies that singlet-dominated particles may form a secluded DM sector. Under such a theoretical structure, the DM achieves the correct abundance by annihilating into a pair of singlet-dominated Higgs bosons by adjusting $κ$'s value. Its scattering with nucleons is suppressed when $λv/μ_{tot}$ is small. This speculation is verified by sophisticated scanning of the theory's parameter space with various experiment constraints considered. In addition, the Bayesian evidence of the general NMSSM and that of $Z_3$-NMSSM is computed. It is found that, at the cost of introducing one additional parameter, the former is approximately $3.3 \times 10^3$ times the latter. This result corresponds to Jeffrey's scale of 8.05 and implies that the considered experiments strongly prefer the general NMSSM to the $Z_3$-NMSSM.

hep-ph↗

arXiv2020

Impact of leptonic unitarity and dark matter direct detection experiments on the NMSSM with inverse seesaw mechanism

In the Next-to-Minimal Supersymmetric Standard Model with the inverse seesaw mechanism to generate neutrino masses, the lightest sneutrino may act as a feasible dark matter candidate in vast parameter space. In this case, the smallness of the leptonic unitarity violation and the recent XENON-1T experiment can limit the dark matter physics. In particular, they set upper bounds of the neutrino Yukawa couplings $λ_ν$ and $Y_ν$. We study such effects by encoding the constraints in a likelihood function and carrying out elaborated scans over the parameter space of the theory with the Nested Sampling algorithm. We show that these constraints are complementary to each other in limiting the theory, and in some cases, they are very strict. We also study the impact of the future LZ experiment on the theory.

hep-ph↗

arXiv2020

Anomalous Muon Magnetic Moment in the Inverse Seesaw Extended Next-to-Minimal Supersymmetric Standard Model

The present work investigates the possibility that both dark matter and the anomalous magnetic moment of the muon may be explained within the context of the inverse seesaw extended Next-to-Minimal Supersymmetric Standard Model (ISS-NMSSM). In ISS-NMSSM, the newly introduced Higgs-neutrino Yukawa coupling $Y_ν$ provides additional Higgsino-sneutrino loop contribution to $(g-2)_μ$. If the deviation between the experimental observations and the Standard Model predictions of the anomalous muon magnetic moment is confirmed by the further experimental and theoretical studies, it can be explained naturally within the ISS-NMSSM framework without conflicting with the current stringent limits on the direct detection of dark matter and Large Hadron Collider searches.

hep-ph↗

arXiv2020

Suppressing the Scattering of WIMP DM with Nucleons in Supersymmetric Theories

The continuously improving sensitivity of dark matter direct detection experiments has limited the interaction between dark matter and nucleons being increasingly feeble, while the dark matter relic density favors it to take part in weak interactions. After taking into account the constraints from the Large Hadron Collider (LHC) search for Higgs bosons and sparticles, it is becoming difficult for the neutralino dark matter in the Minimal Supersymmetric Standard Model and the Next-to-Minimal Supersymmetric Standard Model to possess these two seemingly paradoxical features in their most natural parameter space for electroweak symmetry breaking due to the limited theoretical structure. In contrast, the seesaw extension of the Next-to-Minimal Supersymmetric Standard Model, which was initially proposed to solve the neutrino mass problem, enables the lightest sneutrino to act as a viable dark matter candidate, readily has these features, and thus, it easily satisfies the constraints from dark matter and LHC experiments. Compared with the Type-I seesaw extension, the dark matter physics in the inverse seesaw extension is more flexible, allowing it to be consistent with the experimental results in broader parameter space. We conclude that weakly interacting massive particles (such as the sneutrino in this study) work well in supersymmetric theories as dark matter candidates.

hep-ph↗

arXiv2019

The 96 GeV Diphoton Excess in the Seesaw Extensions of the Natural NMSSM

The Next-to Minimal Supersymmetric Standard Model (NMSSM) with a Type-I seesaw mechanism extends the NMSSM by three generations of right-handed neutrino fields to generate neutrino mass. As a byproduct it renders the lightest sneutrino as a viable DM candidate. Due to the gauge singlet nature of the DM, its scattering with nucleon is suppressed in most cases to coincide spontaneously with the latest XENON-1T results. Consequently, broad parameter spaces in the Higgs sector, especially a light Higgsino mass, are resurrected as experimentally allowed, which makes the theory well suited to explain the long standing $b \bar{b}$ excess at LEP-II and the continuously observed $γγ$ excess by CMS collaboration. We show by both analytic formulas and numerical results that the theory can naturally predict the central values of the excesses in its broad parameter space, and the explanations are consistent with the Higgs data of the discovered Higgs boson, $B-$physics and DM physics measurements, the electroweak precision data as well as the LHC search for sparticles. Part of the explanations may be tested by future DM experiments and the SUSY search at the LHC.

hep-ph↗

arXiv2019

A Bayesian analysis of sneutrino DM in the NMSSM with Type-I seesaw mechanism

In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) with extra heavy neutrino superfields, neutrino may acquire its mass via a seesaw mechanism and sneutrino may act as a viable dark matter (DM) candidate. Given the strong tension between the naturalness for $Z$ boson mass and the DM direct detection experiments for customary neutralino DM candidate, we augment the NMSSM with Type-I seesaw mechanism, which is the simplest extension of the theory to predict neutrino mass, and study the scenarios of sneutrino DM. We construct likelihood function with LHC Higgs data, B-physics measurements, DM relic density and its direct and indirect search limits, and perform a comprehensive scan over the parameter space of the theory by Nested Sampling method. We adopt both Bayesian and frequentist statistical quantities to illustrate the favored parameter space of the scenarios, the DM annihilation mechanism as well as the features of DM-nucleon scattering. We find that the scenarios are viable over broad parameter regions, especially the Higgsino mass $μ$ can be below about $250 {\rm GeV}$ for a significant part of the region, which predicts $Z$ boson mass in a natural way. We also find that the DM usually co-annihilated with the Higgsinos to get the measured relic density, and consequently the DM-nucleon scattering rate is naturally suppressed to coincide with the recent XENON-1T results even for light Higgsinos. Other issues, such as the LHC search for the Higgsinos, are also addressed.

hep-ph↗

arXiv2017

Sneutrino DM in the NMSSM with inverse seesaw mechanism

In supersymmetric theories like the Next-to-Minimal Supersymmetric Standard Model (NMSSM), the lightest neutralino with bino or singlino as its dominant component is customarily taken as dark matter (DM) candidate. Since light Higgsinos favored by naturalness can strength the couplings of the DM and thus enhance the DM-nucleon scattering rate, the tension between naturalness and DM direct detection results becomes more and more acute with the improved experimental sensitivity. In this work, we extend the NMSSM by inverse seesaw mechanism to generate neutrino mass, and show that in certain parameter space the lightest sneutrino may act as a viable DM candidate, i.e. it can annihilate by multi-channels to get correct relic density and meanwhile satisfy all experimental constraints. The most striking feature of the extension is that the DM-nucleon scattering rate can be naturally below its current experimental bounds regardless of the higgsino mass, and hence it alleviates the tension between naturalness and DM experiments. Other interesting features include that the Higgs phenomenology becomes much richer than that of the original NMSSM due to the relaxed constraints from DM physics and also due to the presence of extra neutrinos, and that the signatures of sparticles at colliders are quite different from those with neutralino as DM candidate.

hep-ph↗