arXiv subjects

Weiyao Ke

Publications and source records attributed to Weiyao Ke.

At least 19 recordsLinked to original sources

arXiv2026

Tracing Gluon Saturation through Hadronization at EIC

Gluon saturation provides a window into the nonlinear nature of the strong interaction in nuclear matter. One direct consequence of saturation is the $\boldsymbol{k}_T$ broadening in the final state.We investigate how hadronization reshapes conventional signatures of gluon saturation at EIC within a complete event-generator framework. To this end, we implement in eHIJING an initial-state-radiation algorithm based on nonlinear small-$x$ evolution and complete the events with beam remnants, final-state radiation, and hadronization. In our simulations, the signal of parton-level nuclear $\boldsymbol{k}_T$ broadening is strongly diluted in both the nucleon energy correlator and leading-dihadron azimuthal decorrelation after hadronization. Global hadronic recoil, by contrast, remains sensitive to the underlying $\boldsymbol{k}_T$ broadening. We further demonstrate that Bayesian unfolding of the global hadronic recoil provides access to the underlying hard-scattering $\boldsymbol{k}_T$ distribution. These results establish the global hadronic recoil as a promising saturation observable at the EIC.

hep-ph↗

arXiv2026

Tracing Vacuum Hadronization with Conserved Currents

We show that color triality constrains the nonperturbative states that screen a Wilson-line endpoint, allowing the joint flows of net electric charge, baryon number, and strangeness to probe QCD vacuum hadronization. Whether evaluated from resolved hadrons in a jet initiated by a quark of flavor $f$ or from the corresponding charge correlators, these flows satisfy the Gell-Mann--Nishijima relation $\langle Q_{\rm flow}\rangle_f \simeq I_{3,f} +\frac{1}{2}\left( \langle S_{\rm flow}\rangle_f +\langle B_{\rm flow}\rangle_f \right)$, where $I_{3,f}$ is the third component of the initiating-quark isospin. The net jet baryon number, $\langle B_{\rm flow}\rangle_f\simeq \frac{r_{qq}}{1+r_{qq}}$, directly probes the relative probability of a diquark--antidiquark vacuum excitation, with $r_{qq}$ the diquark-to-quark production ratio. Thus, for $r_{qq}\ll1$, the baryon number carried by the jet is substantially suppressed relative to the initiating-quark value $B_f=1/3$. Likewise, the strange-to-light pair-production ratio, defined by $u\bar u:d\bar d:s\bar s=1:1:r_s$, is encoded in the measured jet strangeness $\langle S_{\rm flow}\rangle_f \simeq S_f+\frac{3r_s}{2+r_s} \left(\frac{1}{3}- \langle B_{\rm flow}\rangle_f\right)$, predicting a nonzero mean net strangeness even in $u$- and $d$-initiated jets. The conserved-current moments appearing in these relations are independent of the renormalization scale. Their simultaneous measurement therefore provides a direct, flavor-resolved probe of vacuum pair production and quantum-number transport during hadronization.

hep-ph↗

arXiv2026

Study the Longitudinal Entropy Deposition using d+Au Collision

Relativistic hydrodynamics successfully describes bulk observables in symmetric heavy-ion collisions, but struggles to reproduce charged-particle rapidity distributions in asymmetric systems such as d+Au collisions. To address this challenge, we introduce two key improvements to the initial-state modeling: sampling deuteron configurations from an ab initio wavefunction, and developing a new longitudinal entropy deposition model that incorporates a transverse entropy deposition coefficient $\beta$ and a rapidity loss term scaling with the number of binary collisions $n_{\rm BC}$. Using the (3+1)-dimensional viscous hydrodynamic model CLVisc coupled with the SMASH afterburner, we simulate d+Au collisions at $\sqrt{s_{\rm NN}} = 200$ GeV and successfully reproduce the experimental charged-particle pseudorapidity distributions across five centrality classes with $\beta = 0.35$, as well as the transverse momentum spectra and anisotropic flow $v_n$. The entropy deposition coefficient $\beta$ and the $n_{\rm BC}$-dependent rapidity loss are found to play crucial roles in achieving this agreement. Furthermore, this longitudinal entropy deposition framework demonstrates excellent universality, as validated in p+Au, $^3$He+Au, and Au+Au collisions. Our entropy deposition mechanism could be widely applied to recent light-nucleus collisions such as O+O, Ne+Ne, and asymmetric systems like Pb+Ne at LHC energies, thereby better constraining the nuclear structure of light nuclei through an improved longitudinal description.

nucl-th↗

arXiv2026

Uncover the correlation between jet energy correlators and multiplicity fluctuations

The energy-energy correlator (EEC) and multiplicity are two fundamental observables probing complementary aspects of QCD jets: the former characterizes the angular structure of energy flows in a scale-dependent manner, while the latter is sensitive to the entire history of particle production. In this \emph{Letter}, we uncover a nontrivial correlation between them by studying the EEC as a function of jet internal multiplicity. We introduce the multiplicity-conditioned EEC jet function (MCJF) and perform a factorization calculation to next-to-leading order accuracy. It is found that, for jet samples selected at a given normalized multiplicity $\nu = N_{\rm ch}/\langle N_{\rm ch} \rangle$, the EEC in the angular region $\Lambda_{\rm QCD}/p_{T,\rm jet}\ll\chi\ll R$ acquires a $\nu$-dependent anomalous dimension. Thus the $\nu$-conditioned EEC provides a direct and robust probe to the multiplicity generating function in the perturbative regime. In addition, understanding $\nu$ dependence of the EEC is also crucial for isolating possible multiplicity-dependent bias effects in the EEC measurements in nuclear environment.

hep-ph↗

arXiv2025

Renormalization Group Evolution for In-medium Energy Correlators

We present a first-principles analysis of the renormalization group (RG) evolution of the two-point energy-energy correlator (EEC) in light-quark and gluon jets propagating through nuclear matter. Our work focuses on the analytic structure of the RG equations in the thin-medium regime, highlighting how collinear emissions in the presence of a dense QCD medium reshape the EEC observables. We work in the opacity expansion of the SCET$_{\rm G}$ formalism, where the propagating quarks and gluons interact with the medium via Glauber gluon exchanges. We compute the corresponding one-loop jet functions using the medium-induced splitting kernels at first order in opacity and perform resummation at leading logarithmic (LL) order. In particular, we identify an experimentally accessible regime of jet energies and EEC angles where one can directly investigate the medium-induced scale evolution and extract the corresponding opacity-one correction to the anomalous dimensions. Furthermore, we demonstrate analytically, using the method of regions, the Coulomb-logarithmic enhancement regulated by plasma screening for EEC. We compare our theoretical predictions with experimental data in $p$-Pb collisions and make projections for O-O collisions to test whether energy correlators could serve as sensitive probe of the quark-gluon plasma (QGP) dynamics in small collision systems, offering a robust and model-independent avenue for constraining jet evolution in QCD matter.

hep-ph↗

arXiv2025

Fermi-liquid view of viscosity in cold and dense nucleon matter

We develop a framework to calculate transport properties in cold, dense relativistic quasiparticle system within the Fermi-liquid theory at the mean-field level. Building on our previous study J. Li \emph{et al.} [Phys. Rev. C \textbf{111}, 044904 (2025)], we start from the linearized relativistic Boltzmann equation tailored to quasiparticles with medium-dependent dispersion relation and implement Landau matching conditions, proving that the bulk viscosity is manifestly nonnegative. A low-temperature expansion then yields leading-order ($T/\mu^*$) expressions for the shear ($\eta$) and bulk ($\zeta$) viscosities, where the behavior $\zeta/\eta \propto (T/\mu^*)^4$ in the degenerate regime is found to be robust against quasiparticle mass correction. We couple the kinetic framework to a Walecka-type mean-field equation of state and compute $\eta$ and $\zeta$ for cold, dense nucleon matter. The transport properties of nucleonic matter in the degenerate regime can be relevant for intermediate beam-energy nuclear experiments.

nucl-th↗

arXiv2025

Open heavy-flavor transport and hadronization in heavy-ion collisions

We develop a comprehensive model for heavy-quark evolution in a realistic QGP, from their production in the initial collision to hadronic freeze-out. Heavy-quark transport is described by a Langevin approach including medium-induced radiation, coupled to a 2+1D viscous hydrodynamic bulk evolution. Transport coefficients are obtained from non-perturbative $T$-matrix calculations with resonant correlations near the transition temperature. Hadronization is implemented via two fragmentation+recombination schemes: an improved sudden coalescence model and a resonance recombination model. We present results for key open heavy-flavor observables, i.e., the nuclear modification factor and elliptic flow, and compare to LHC Pb-Pb data at $\sqrt{s_{\NN}}$=5.02\,TeV.}

hep-ph↗

arXiv2025

Internal multiplicity distributions of jets from nonlinear evolution within the jet function framework

Jets selected with high internal charged-particle multiplicity exhibit markedly different substructure patterns compared to inclusive jet samples. Such correlations motivate a systematic study of jet observables as a function of the normalized multiplicity, $\nu = N_{\rm ch}/\langle N_{\rm ch}\rangle$. In this work, we develop a theoretical framework for the full charged-particle multiplicity distribution of exclusive and inclusive jets, formulated within the jet-function approach. The hard production and jet function are evaluated at NLO+LL$_R$ accuracy. The internal parton dynamics governing the multiplicity distribution are described by coupled nonlinear branching equations with angular ordering, supplemented by a nonperturbative modeling term that accounts for hadron-level effects. The resulting predictions are validated against \textsc{Pythia8} simulations and compared with CMS data. We examine the effects of both nonperturbative and perturbative components in shaping the multiplicity distribution, and show that Koba--Nielsen--Olesen (KNO) scaling is notably violated in the region $\nu > 2$ in the full solution, with a trend consistent with Monte Carlo results. This framework that numerically solves the nonlinear multiplicity evolution goes beyond DLA-like approximations and reproduces key features seen in event generators, providing a solid foundation for future investigations of multiplicity -- conditioned jet substructure within the jet function formalism.

hep-ph↗

arXiv2025

Nonperturbative Heavy-Flavor Transport Approach for Hot QCD Matter

The heavy charm and bottom quarks are unique probes of the transport properties of the quark-gluon plasma (QGP) and its hadronization in high-energy nuclear collisions. A key challenge in this context is to embed the interactions of the heavy quarks in the expanding medium compatible with the strong-coupling nature of the QGP, and thus to unravel the underlying microscopic mechanisms. In the present work we progress toward this goal by combining recent $T$-matrix interactions for elastic scattering with an effective transport implementation of gluon radiation, and apply these in a Langevin framework in a viscous hydrodynamic evolution. Hadronization of heavy quarks is evaluated using a modern recombination model with 4-momentum conservation, supplemented with fragmentation constrained by data in proton-proton collisions. Deploying this approach to charm-hadron observables in Pb-Pb collisions at the LHC yields fair agreement with experiment while also identifying areas of further systematic improvement of the simulations and its current input.

nucl-th↗

arXiv2025

From wave-function to fireball geometry: the role of a restored broken symmetry in ultra-relativistic collisions of deformed nuclei

Traditional Monte Carlo (MC) Glauber models treat the shapes of deformed nuclei classically; that is, in a collision event, each nucleus is randomly assigned a configuration with fixed deformation parameters and orientation (collective coordinates). Quantum mechanically, however, a valid nuclear ground state must be a superposition of these configurations to preserve rotational symmetry, creating entanglement in the nucleon wave function. We show that for collisions with a moderate number of participants, this quantum superposition -- particularly in the orientation of deformed nuclei -- has non-negligible impacts on the initial geometry of the quark-gluon plasma fireball. We propose a minimal extension to the MC Glauber model to approximately incorporate these superposition effects and find a $6$-$8\%$ reduction in the second-order eccentricity in central Ne-Ne and Ne-Pb collisions relative to results from classical treatments of nuclear orientation. Though these effects are expected to be small for large collision systems such as U-U, this study demonstrates the importance of properly accounting for quantum superposition and the associated off-diagonal information when studying nuclear deformation in ultra-relativistic nuclear collisions.

nucl-th↗

arXiv2025

Bayesian inference of the magnetic field and chemical potential on holographic jet quenching in heavy-ion collisions

Jet quenching is studied in a background magnetic field and a finite baryon chemical potential. The production of energetic partons is calculated using the next-to-leading order (NLO) perturbative Quantum Chromodynamics (pQCD) parton model, while the parton energy loss formula is obtained from the AdS/CFT correspondence incorporating the magnetic field and baryon chemical potential effects. Using Bayesian inference, we systemically compare the theoretical calculations with experimental data for the nuclear modification factor $R_{AA}$ of the large transverse momentum hadrons in different-centrality nucleus-nucleus collisions at 0.2, 2.76 and 5.02 TeV, respectively. The form of the holographic energy loss leads to a strong negative correlation between the magnetic field and the chemical potential after the calibration, from which we discussed the sensitivity of jet quenching phenomena to magnetic field and baryon chemical potential.

hep-ph↗

arXiv2024

Transport coefficients of dense nucleon matter at low temperature

The transport property of cold and dense nucleon matter is important for nuclear physics but is relatively less studied than that at finite temperatures. In this paper, we present a primary study of bulk and shear viscosities in the limit $T/\mu_B \ll 1$, where $T$ and $\mu_B$ are the temperature and the baryon chemical potential. The analysis is performed for a generic system where nucleons are dressed by the condensation of both scalar and vector interactions. Under the relaxation time approximation of the Boltzmann equation, we compute the viscosities of the system to leading power in $T/\mu_B$ expansion and establish a relation between the thermodynamic potential and transport coefficients, including bulk viscosity ($\zeta$) and shear viscosity ($\eta$). It is found that hydrodynamic stability ($\zeta>0$) imposes additional constraints on the thermodynamic potential. As an example, these relations are applied to the Walecka model. The fluid properties of the cold and dense nucleon matter are characterized by the dimensionless combination of viscosities times the quasi-Fermi momentum over the enthalpy. Furthermore, we discuss the implication of the stability condition on the range of applicability of the model.

nucl-th↗

arXiv2024

Imperceptible Adversarial Attacks on Point Clouds Guided by Point-to-Surface Field

Adversarial attacks on point clouds are crucial for assessing and improving the adversarial robustness of 3D deep learning models. Traditional solutions strictly limit point displacement during attacks, making it challenging to balance imperceptibility with adversarial effectiveness. In this paper, we attribute the inadequate imperceptibility of adversarial attacks on point clouds to deviations from the underlying surface. To address this, we introduce a novel point-to-surface (P2S) field that adjusts adversarial perturbation directions by dragging points back to their original underlying surface. Specifically, we use a denoising network to learn the gradient field of the logarithmic density function encoding the shape's surface, and apply a distance-aware adjustment to perturbation directions during attacks, thereby enhancing imperceptibility. Extensive experiments show that adversarial attacks guided by our P2S field are more imperceptible, outperforming state-of-the-art methods.

cs.CV↗

arXiv2024

Anisotropic jet broadening and jet shape

In this paper, we explore the use of jet substructure as a way of probing phenomena which break the isotropic behavior of jets, such as jet propagation through an anisotropically flowing quark-gluon plasma or spin correlations. We introduce two novel observables for this purpose: the azimuthal-dependent jet broadening and the azimuthal-dependent jet shape, which generalize the traditional isotropic substructure studies. Using Soft-Collinear Effective Theory, we explicitly calculate the jet functions associated with these observables with a standard jet axis and with a Winner-Take-All jet axis in both the resummed and fixed order limits. While our analysis first and foremost establishes the formalism for the azimuthal-dependent jet substructure, it also brings to light new results for jet substructure in the azimuthally integrated case, such as the semi-inclusive jet function and the exclusive jet shape for the Winner-Take-All axis, and the jet broadening in the fixed order region. As an illustrative example for the new formalism we demonstrate that the azimuthal-dependent jet broadening can be used as a direct probe of the transversity parton distribution function in deep inelastic scattering.

hep-ph↗

arXiv2024

Toward a first-principles description of transverse momentum dependent Drell-Yan production in proton-nucleus collisions

In this paper, we study the parton dynamics in Drell-Yan collisions involving proton-nuclei interactions in the limit of small transverse momentum, emphasizing the role of the cold nuclear matter effects. The distribution of transverse momentum that enter into these collisions differs from that in Drell-Yan collisions with free nucleons in two distinct ways: the intrinsic parton structure of the TMDs are altered, the perturbative dynamics undergo additional modification due to interactions with the nuclear medium. In this paper, we focus on the perturbative dynamics, which we demonstrate enter from forward scattering between the parton constituents of the proton and the nuclear medium. We then derive these partonic contributions to the TMD Drell-Yan cross section up to next-to-leading order in the strong coupling constant and to the first order in the medium opacity. We demonstrate that the collinear and rapidity divergences related to parton showers in matter lead to i) an in-medium renormalization group equation that encodes the transverse momentum dependence of parton energy loss, and ii) a Balitsky-Fadin-Kuraev-Lipatov evolution equation for the forward scattering cross section. We discuss the relation of our results to the phenomenological extraction of nuclear TMDs and apply the new formalism to Drell-Yan production at small transverse momenta in $p$+$A$ reactions.

hep-ph↗

arXiv2024

eHIJING: an Event Generator for Jet Tomography in Electron-Ion Collisions

We develop the first event generator, the electron-Heavy-Ion-Jet-INteraction-Generator (eHIJING), for the jet tomography study of electron-ion collisions. In this generator, energetic jet partons produced from the initial hard scattering undergo multiple collisions with the nuclear target. The collision rate is proportional to the transverse-momentum-dependent (TMD) gluon density in the nucleus, which is given by a simple model inspired by the physics of gluon saturation. Medium-modified QCD splitting functions within the higher-twist (HT) and generalized higher-twist (GHT) frameworks are utilized to simulate parton showering in the nuclear medium that takes into account the non-Abelian Landau-Pomeranchuck-Midgal interference effect. Employing eHIJING, we revisit hadron production in semi-inclusive deep inelastic scattering (SIDIS) as measured by EMC, HERMES, and recent CLAS experiments. eHIJING with both GT and GHT frameworks gives reasonably good descriptions of these experimental data. Predictions for experiments at the future electron-ion colliders are also provided. It is demonstrated that future measurements of the transverse momentum broadening of single hadron spectra can be used to map out the two-dimensional kinematic ($Q^2, x_B$) dependence of the jet transport coefficient $\hat{q}$ in cold nuclear matter.

hep-ph↗

arXiv2024

Understanding parton evolution in matter from renormalization group analysis

We perform a renormalization group (RG) analysis of collinear hadron production in deep inelastic scattering on nuclei. We consider the limit where the parent parton energy $E$ is large, while the medium opacity $L/λ_g$ remains small. We identify the fixed order and leading $\ln(E/ξ^2 L)$ enhanced medium contributions to the semi-inclusive cross sections and derive RG equations that resum multiple emissions near the endpoints of the splitting functions at first order in opacity. These evolution equations treat the same type of radiation enhancement in matter as the modified Dokshitzer-Gribov-Lipatov-Altarelli-Parisi approach, but differ in the way one regulates the collinear divergences. They provide a unique analytic insight into the problem of resummation and a faster and more efficient path to phenomenology. The new RG evolution framework is applied to study fragmentation in $e$A reactions.

hep-ph↗

arXiv2024

Non-hydrodynamic response in QCD-like plasma

Quark-gluon plasma's (QGP) properties at non-hydrodynamic and non-perturbative regimes remain largely unexplored. Here, we examine the response functions describing how a QGP-like plasma responds to initial energy-momentum disturbance in both static and Bjorken-expanding plasma at non-hydrodynamic gradient using the Boltzmann equation in the relaxation-time approximation (RTA). We show that the resulting response functions are remarkably similar in both static and expanding backgrounds at non-hydrodynamic gradients. While non-hydrodynamic response can not be described by the conventional first-order and second-order theories, its behavior is reasonably captured by the extended version of hydrodynamics proposed by us (arXiv: 2208.01046). The potential sensitivity of the Euclidean correlator to non-hydrodynamic response is also illustrated.

nucl-th↗