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Mei Huang

Publications and source records attributed to Mei Huang.

At least 19 recordsLinked to original sources
arXiv2026

Deconfining Phase Transition under Real Rotation: A Matrix Model Study

We construct a matrix model to study the deconfining phase transition for a pure gluon plasma that is confined in a cylinder of radius ${\cal R}$ and rotating rigidly at a real-valued angular velocity $\Omega$, satisfying $\mathcal{R} \Omega<1$. The deconfining phase transition arises due to the competition between two terms that constitute the matrix model. The perturbative term comes from the one-loop effective potential computed in the presence of a background field, while the non-perturbative term represents a correction to the perturbative contribution which is brought about by taking into account an effective mass of the gauge fields. Our results show that real rotation induces a radial inhomogeneity of the system and the deconfining temperature $T_c$ drops away from the rotation axis which is consistent with the Tolman-Ehrenfest law. As for the $\Omega$-dependence of $T_c$, it relies on our assumptions of the gluon effective mass. For a constant mass, $T_c$ is found to always decrease with increasing $\Omega$. A non-monotonic behavior of $T_c$ shows up when a $\Omega$-dependent mass is considered, leading to a qualitative change in the region of small angular velocity. In addition, by setting $\Omega=0$ to eliminate rotational effects, we also demonstrate that the finite-volume effect reduces the deconfining temperature relative to the infinite-volume limit. Comparisons between our results and those from various lattice simulations and phenomenological models suggest that controversy remains over how the deconfining phase transition is modified by real rotation and further work is required to reach a definite conclusion.

hep-ph↗
arXiv2026

Medium effect on spin alignment of strange and charm vector mesons

Understanding the spin alignment of vector mesons in relativistic heavy-ion collisions requires a nonperturbative description of their spin-dependent in-medium properties. We investigate this problem within a unified four-flavor soft-wall holographic framework that combines an anisotropic Einstein--Maxwell--dilaton background at finite temperature, baryon chemical potential, and angular velocity. Spin alignment is determined from the medium-induced splitting of the spin-resolved vector-current spectral functions through an instantaneous freeze-out prescription. We systematically study the strange and charm vector mesons $K^{*}$, $\phi$, $D^{*}$, $D_s^{*}$, and $J/\psi$ and the dependence of their spin alignment on transverse momentum, rapidity, temperature, baryon chemical potential, and angular velocity. We find that the heavy charm vector mesons $D^{*}$, $D_s^{*}$, and $J/\psi$ mesons exhibit $\rho_{00}>1/3$ at low transverse momentum, whereas the light strange vector mesons $K^{*}$ and $\phi$ exhibit the opposite low-momentum behavior and angular distributions with $\rho_{00}<1/3$. We trace this flavor-dependent separation to the different locations of the vacuum mass shell relative to the thermally shifted longitudinal and transverse spectral peaks. The results qualitatively reproduce several trends observed at low and intermediate transverse momentum. Spin alignment is insensitive to baryon chemical potential and only weakly affected by angular velocity. These results establish an equilibrium holographic baseline for vector-meson spin alignment across flavor sectors and help delineate the regimes in which additional mechanisms, such as nonequilibrium evolution, fluctuations, and hard production, become important.

hep-ph↗
arXiv2026

Detecting Multiple Phase Transitions in Lattice Systems with Intrinsic Dimensions

Lattice systems with multiple nearby transitions pose two related challenges: resolving distinct transition scales and identifying the degrees of freedom primarily associated with each transition. We show that the intrinsic dimension of Monte Carlo configuration ensembles, estimated by the two-nearest-neighbors method, provides a geometric diagnostic for both problems. In the two-dimensional $q$-state clock model, the intrinsic dimension distinguishes the ordered, quasi-critical, and disordered regimes for both well-separated ($q=9$) and closely spaced ($q=5$) Berezinskii--Kosterlitz--Thouless transitions. In the $q=5$ case, the intermediate phase appears as a broad low-dimensional valley even when energy and magnetization do not separately resolve the two transitions. In the four-dimensional $U(1)$ Higgs model, we introduce channel-decomposed intrinsic dimensions based on gauge-invariant plaquette and Higgs variables. The dominant response of each channel tracks transitions associated with the corresponding degrees of freedom, while the combined channel retains features of both. We further show that intrinsic dimensions evaluated directly on gauge-variant fields are dominated by gauge-orbit directions, demonstrating the importance of removing gauge redundancy before interpreting configuration-space geometry. These results establish channel-decomposed intrinsic dimension as a geometric probe of lattice systems with multiple transitions and motivate its application to disentangling deconfinement and chiral crossover scales in full QCD.

hep-lat↗
arXiv2026

Exploring the chiral magnetic effect in Au+Au collisions at $\sqrt{s_{NN}}=7.7-200$ GeV through Chiral Anomaly Transport

High-energy heavy-ion collisions have the potential to create local domains of chirality-imbalanced quarks, reflecting the topological characteristics of quantum chromodynamics. This phenomenon can potentially induce local $\mathcal{P}$ and $\mathcal{CP}$ violations in the quark-gluon plasma. The Chiral Magnetic Effect (CME) predicts an electric charge separation along the intense magnetic field generated during these collisions, which is typically investigated through charge-dependent azimuthal correlations ($\Delta\gamma$). In this work, we investigate the CME in Au+Au collisions at $\sqrt{s_{NN}} = 7.7 - 200$ GeV using a multiphase transport (AMPT) model equipped with a Chiral Anomaly Transport (CAT) module. we employ two independent methods: direct subtraction of the correlator $\langle N_{part}\Delta\gamma\rangle$ between simulations with zero and finite chiral chemical potential $\mu_5$, and the event-shape-selection (ESS) approach. Our results reveal a significant CME signal within the energy range of 11.5-27 GeV and the centrality range of $20-50\%$, where the AMPT model aligns well with STAR experimental data. Furthermore, the CME fractions extracted by both methods are consistent within uncertainties across these energies. However, the CME signal disappears at both 7.7 and 200 GeV. These findings underscore that the observability of the CME critically depends on both the dynamic evolution of the magnetic field and the chemical freeze-out time of the partonic phase, which vary significantly with collision energy.

hep-ph↗
arXiv2026

Schwinger-Keldysh effective field theory of type-B Goldstone: near-diagonal geometry and Berry term

In this work, we formulate a finite temperature Schwinger-Keldysh effective field theory for type-B Goldstone modes. In particular, we organize the required two time contour structure by a near-diagonal geometry in which the r-type field is interpreted as the physical Goldstone configuration and the a-type field is identified as corresponding tangent displacement. Within this geometric viewpoint, the Berry term essential for type-B Goldstones is obtained directly through the transgression of the Berry curvature. Moreover, we show that this exact Berry transgression is compatible with dynamical KMS condition. In order to construct the conservative, dissipative and noise sectors, we classify possible tensors globally defined on the coset manifold. Based on this framework, we discuss in detail two concrete model examples. The dispersion relations of the Goldstone modes and the associated two-point correlation functions are calculated in the presence of dissipation.

hep-th↗
arXiv2026

A Chromomagnetic Mechanism for the Rotational Phase Transition of Gluonic Matter

Rotation serves as a pivotal control parameter for QCD matter, yet effective models and lattice QCD yield conflicting predictions regarding its effect on the deconfinement transition. Using a rotation-magnetic correspondence within a holographic framework, we investigate the rotational response of pure gluonic matter. Calibrated against lattice QCD data at imaginary angular velocity, we find real rotation enhances chromomagnetic string tension and raises deconfinement temperature, consistent with lattice QCD analytic-continuation predictions. The temperature dependence of chromomagnetic string tension dominates the system's Barnett response: weak low-temperature tension induces the negative Barnett effect, and slightly above the transition, spin contributions prevail to generate an anomalous negative total moment of inertia. Since growing angular velocity further strengthens chromomagnetic string tension and suppresses spin-dominated inversion, this anomalous regime only survives at weak real rotation and vanishes at large angular velocity. At high temperature, fully restored strong string tension stabilizes conventional Barnett behavior. Stemming from the melting and thermal restoration of nonperturbative chromomagnetic flux tubes, our results establish the chromomagnetic-induced inertia inversion (CII) mechanism as the microscopic origin of this anomalous rotational response.

hep-ph↗
arXiv2026

Flavor-Dependent QCD Critical Endpoint and Dual-Channel Fluctuations from Multi-Charge Holography

We construct a thermodynamically self-consistent holographic QCD framework incorporating multiple conserved charges. By introducing three independent bulk $U(1)$ gauge fields, our Einstein-Maxwells-dilaton (EMsD) model naturally accommodates the coupled chemical potential landscape $(\mu_B, \mu_Q, \mu_S)$ inherent to realistic heavy-ion collisions. Crucially, thermodynamic consistency is enforced at the level of holographic renormalization, ensuring exact Maxwell cross-derivative relations without ad hoc patching. Calibrated exclusively at zero density, the model exhibits genuine predictive power for finite-density thermodynamics. We reveal that finite charge and strangeness densities induce pronounced nonmonotonic shifts in the critical endpoint (CEP) location. Furthermore, by mapping the freeze-out trajectories, we demonstrate that the allowed parameter bands robustly encompass empirical hadron resonance gas (HRG) fits. Within this physical regime, higher-order cumulant ratios for both net-baryon and net-charge channels exhibit coherent critical peaks at $\sqrt{s_{NN}} \approx 5\text{--}7\,\text{GeV}$. This hierarchical dual-channel signature provides a decisive, background-free strategy for the ongoing experimental search for the QCD critical point.

hep-ph↗
arXiv2026

Hyperon-Nucleon Spectrometer

Chirality lies at the heart of low-energy QCD, governing the symmetry structure that shapes hadron masses and strong interaction dynamics. Among the most compelling open questions tied to chiral dynamics and spontaneous chiral symmetry breaking is the longstanding $\Lambda$ polarization puzzle, in which $\Lambda$ hyperons produced in unpolarized hadronic collisions exhibit a surprisingly large transverse polarization that remains theoretically unexplained. This whitepaper presents the proposal for the Hyperon-Nucleon Spectrometer (H-NS) at the High-Intensity heavy-ion Accelerator Facility (HIAF). Leveraging the high energy and high intensity of HIAF's proton and heavy-ion beams, the H-NS experiment will perform systematic studies of hyperon polarization phenomena and their underlying mechanisms in proton-proton ($pp$), proton-nucleus ($pA$), and nucleus-nucleus ($AA$) collisions in the fixed target mode. A wide-range beam energy scan, including proton beams from 3 GeV up to 9.3 GeV (HIAF) and up to 32 GeV (upgraded HIAF), will be conducted to examine the dependence of polarization on collision energy. The spectrometer is designed with specialized detectors capable of high-precision reconstruction of final-state baryon polarizations. Among its many interesting and important measurements, H-NS will simultaneously measure hyperon and proton spin observables to explore the polarization mechanism in hadronic interactions and the spin structure of baryons. Furthermore, the use of $pA$ and $AA$ collisions will enable detailed investigations of cold and hot nuclear matter effects on spin polarization. Its physics program and detector development will significantly benefit the future Electron-ion Collider in China.

physics.ins-det↗
arXiv2026

Purely quadratic non-Gaussianity from tachyonic instability: Primordial black holes and scalar-induced gravitational waves

We investigate primordial black hole (PBH) formation in a cosmological scenario where curvature perturbations follow purely quadratic non-Gaussianity, $\zeta = A(\phi^2-langle\phi^2\rangle)$, arising from tachyonic instability in multicomponent inflationary models. Within an extended Press-Schechter framework based on the compaction function, we derive the probability distribution of the linear compaction function and its asymptotic exponential tail, demonstrating that the PBH abundance is exponentially sensitive not only to the amplitude of perturbations but also to the correlation coefficient $\rho$ between the smoothed field and its radial gradient. We further find that, in this tachyonic amplification scenario, the spectral width of the curvature power spectrum plays a decisive role in avoiding PBH overproduction: broad spectra yield mildly negative $\rho$ and fail to suppress PBH formation, while sufficiently narrow spectra drive $\rho \to -1$, resulting in exponential suppression while maintaining a sizable gravitational-wave signal. Thermal inflation serves as a benchmark for asteroid-mass PBH dark matter and high-frequency scalar-induced gravitational waves potentially detectable by future space-based interferometers, but its typically broad spectra make it challenging to reconcile pulsar timing array observations with PBH constraints.

astro-ph.CO↗
arXiv2026

SAGE Celer 2.6 Technical Card

We introduce SAGE Celer 2.6, the latest in our line of general-purpose Celer models from SAGEA. Celer 2.6 is available in 5B, 10B, and 27B parameter sizes and benefits from extensive architectural modifications and further pre-training on an undisclosed model. Using our Inverse Reasoning (IR) pipeline, SAGEA natively trains Celer 2.6 to validate its own logic paths, minimizing cascading error and hallucination in complex reasoning tasks. Celer 2.6 also boasts natively integrated multimodal functionality with an end-to-end vision encoder to avoid common pitfalls in adapter-based approaches. Celer 2.6 provides highly competitive results on mathematics, coding, and general intelligence benchmarks (ACUMEN), along with low latency. Most importantly, Celer 2.6 is specifically optimized for South Asian language support, with a custom tokenizer for the Devanagari script and strong performance in both Nepali and Hindi without sacrificing English reasoning ability.

cs.CL↗
arXiv2026

Probing the chiral and $U(1)$ axial symmetry restoration via meson susceptibilities in holographic QCD

We investigate the restoration patterns of chiral and $U(1)$ axial symmetries at finite temperature using a soft-wall holographic QCD model. The study employs two distinct parameter sets (Case I and Case II), both calibrated to reproduce a pseudocritical temperature $T_{\rm pc} \sim 155$ MeV and the physical pion mass. The temperature dependence of the light and strange quark condensates confirms a smooth chiral crossover transition, with pseudocritical temperatures of $T_{\rm pc}=0.157$ GeV and $T_{\rm pc}=0.154$ GeV for Cases I and II, respectively. The screening masses of chiral partner mesons ($\pi$-$\sigma$ and $\eta$-$a_0$) become degenerate near $T_{\rm pc}$, providing a clear signature of chiral symmetry restoration. Analysis of the corresponding meson susceptibilities further supports this conclusion. However, the indicator for $U(1)$ axial symmetry restoration, $\chi_\pi - \chi_{a_0}$, vanishes at a temperature $T \sim 0.190 $ GeV, which indicates a distinct restoration scale with chiral symmetry restoration scale within the present holographic framework. The temperature-dependent topological susceptibility $\chi_{\rm top}^{1/4}$ is also computed, showing a sharp drop near $T_{\rm pc}$ and a subsequent slight decrease. While the model qualitatively captures established features of the chiral transition, the results highlight a limitation in the qualitative description of the $U(1)$ axial anomaly compared to LQCD in our work.

hep-ph↗
arXiv2026

Interpretable Maximum Margin Deep Anomaly Detection

Anomaly detection is a crucial machine-learning task with wide-ranging applications. Deep Support Vector Data Description (Deep SVDD) is a prominent deep one-class method, but it is vulnerable to hypersphere collapse, often relies on heuristic choices for hypersphere parameters, and provides limited interpretability. To address these issues, we propose Interpretable Maximum Margin Deep Anomaly Detection (IMD-AD), which leverages a small set of labeled anomalies and a maximum margin objective to stabilize training and improve discrimination. It is inherently resilient to hypersphere collapse. Furthermore, we prove an equivalence between hypersphere parameters and the network's final-layer weights, which allows the center and radius to be learned end-to-end as part of the model and yields intrinsic interpretability and visualizable outputs. We further develop an efficient training algorithm that jointly optimizes representation, margin, and final-layer parameters. Extensive experiments and ablation studies on image and tabular benchmarks demonstrate that IMD-AD empirically improves detection performance over several state-of-the-art baselines while providing interpretable decision diagnostics.

cs.LG↗
arXiv2026

Holographic QCD equation of state constrained by lattice QCD: neural-ODE for probe-limit and a back-reaction test

We study the equation of state (EoS) of QCD matter in a bottom-up holographic setup that combines an Einstein-Maxwell-dilaton (EMD) sector with an improved Karch-Katz-Son-Stephanov (KKSS) flavor action. In the probe approximation, we perform an inverse reconstruction of the model functions by parameterizing them with neural networks and solving the EMD equations via a differentiable ODE solver (a neural ODE framework), calibrating the model to a $(2+1)$-flavor lattice-QCD EoS at finite temperature and finite baryon chemical potential. The reconstructed model functions are then parametrized and kept fixed across thermodynamic states. Next, viewing the EMD sector as an effective description of pure Yang--Mills theory, we fix its parameters by fitting the $\mu_B=0$ lattice pure-glue EoS using a hybrid optimization strategy. Finally, we go beyond the probe limit and solve the coupled EMD$+$KKSS equations with back-reaction, using the pure-glue-calibrated EMD sector as a fixed input and varying the KKSS couplings to compare with the $\mu_B=0$ two-flavor lattice EoS. We find a visible mismatch and a high-temperature behavior in which the back-reacted dimensionless ratios approach a nearly $\beta_1$-insensitive plateau close to the pure-glue baseline, providing a simple structural diagnostic for the present flavor-sector truncation.

hep-ph↗
arXiv2026

Chromomagnetic condensation and perturbative confinement induced by imaginary rotation in SU(2) Yang-Mills Theory

We perturbatively investigate the rotation effect on the Polyakov loop potential in SU(2) gauge theroy within a chromomagnetic background. It is observed that the imaginary rotation spontaneously induces both confinement and chromomagnetic condensation at high temperatures, thereby provides a perturbative window to explore non-perturbative dynamics. Compared to the case without including the induced chromomagnetic field, the perturbative confinement transition becomes first-order, with a temperature-dependent phase boundary that asymptotically approaches $\tilde{\Omega}_c = \pi/\sqrt{3}$ at high temperatures. This leads to a significantly enriched $\tilde{\Omega}$-$T$ phase diagram characterized by an expanded deconfined region. For real angular velocities, we find that the chromomagnetic condensate decreases with increasing rotation, and that the coupling between rotation, spin, and the chromomagnetic background leads to a cusp in the Polyakov loop potential, suggesting that the underlying dynamics could be more intricate.

hep-ph↗
arXiv2026

Spectral function for pions in magnetic field

This study examines the spectral functions of neutral ($\pi_0$) and charged ($\pi_{\pm}$) pions under a uniform magnetic field using the SU(2) Nambu-Jona-Lasinio (NJL) model with the Ritus method. The analysis highlights the complex interplay of magnetic field effects, thermal influences, and chiral symmetry on meson properties in extreme QCD environments. For $\pi_0$, whose properties are governed by the behavior of its constituent quarks, magnetic field-induced Landau levels lead to a multi-peak structure in its spectral function, reflecting stable and resonance solutions that evolve with temperature, showing shifts and critical enhancements near chiral restoration. For $\pi_{\pm}$, cross terms that come from the asymmetry between the constituent quarks introduce Landau cuts alongside Unitary cuts, indicating damping effects, with decay widths narrowing at higher temperatures, suggesting increased stability.

hep-ph↗
arXiv2026

SAGE-32B: Agentic Reasoning via Iterative Distillation

We demonstrate SAGE-32B, a 32 billion parameter language model that focuses on agentic reasoning and long range planning tasks. Unlike chat models that aim for general conversation fluency, SAGE-32B is designed to operate in an agentic loop, emphasizing task decomposition, tool usage, and error recovery. The model is initialized from the Qwen2.5-32B pretrained model and fine tuned using Iterative Distillation, a two stage training process that improves reasoning performance through rigorously tested feedback loops. SAGE-32B also introduces an inverse reasoning approach, which uses a meta cognition head to forecast potential failures in the planning process before execution. On agentic reasoning benchmarks including MMLU-Pro, AgentBench, and MATH-500, SAGE-32B achieves higher success rates in multi tool usage scenarios compared to similarly sized baseline models, while remaining competitive on standard reasoning evaluations. Model weights are publicly released at https://huggingface.co/sagea-ai/sage-reasoning-32b

cs.AI↗
arXiv2025

HoloNet: Toward a Unified Einstein-Maxwell-Dilaton Framework of QCD

We propose HoloNet, a neural-network framework that unifies lattice QCD(LQCD) thermodynamics and holographic Einstein-Maxwell-Dilaton (EMD) theory within a data-to-holography pipeline. Instead of assuming specific functional forms, HoloNet learns the metric profile $A(z)$ and the gauge-dilaton coupling $f(z)$ directly from 2+1-flavor LQCD data at $\mu=0$. These learned functions are embedded into the EMD equations, enabling the model to reproduce the lattice equation of state and baryon number fluctuations with high fidelity. Once trained, HoloNet provides a fully data-driven holographic description of QCD that extends naturally to finite density, allowing us to map the phase diagram and estimate the location of the critical end point (CEP). The reconstructed potential $V(\phi)$ and coupling $f(\phi)$ agree quantitatively with those obtained from holographic renormalization, demonstrating that HoloNet can consistently bridge different holographic models.

hep-lat↗
arXiv2025

Primordial Quark Stars Made of Long-lived False Vacuum

A false vacuum could be a profound ingredient of fundamental physics, yet its direct detection in laboratories is hindered when the lifetime is exponentially long. Conventional static phase diagrams often discard metastable false vacuum, we show that, however, in a dynamical treatment of a first-order QCD phase transition at large quark chemical potential that strongly suppresses tunneling, cosmologically long-lived, and thus indispensable false vacuum naturally arises, and makes nontrivial contribution to constituting primordial quark objects. We identify two distinct branches of such primordial quark objects: quark star crusted with false vacuum, and nugget specifically referring to quark star in global false vacuum, which may account for a population of small compact stars. Some long-lived primordial objects may have survived until the late Universe, and hopefully sow the seeds of high red-shift galaxies. Its false vacuum decay can power ultra-energetic long $\gamma$-ray bursts and kHz gravitational waves within multi-messenger facilities, rendering itself an astrophysical and thus testable phenomenon.

hep-ph↗