arXiv subjects

Enke Wang

Publications and source records attributed to Enke Wang.

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

Low-energy Muon-Nucleon scattering experiment: LUNE (White Paper)

The HIAF will provide high-intensity, high-quality muon beams with momenta from 0.5 to 7.5 GeV/c. This energy range is uniquely suited for precision muon scattering, bridging the gap between low-energy electron facilities and future high-energy lepton-ion colliders. In particular, HIAF will enable precision measurements with both positive and negative muon beams over a broad kinematic range, complementing existing electron-scattering facilities such as JLab, EicC and EIC. Based on HIAF muon source, the LUNE Collaboration has been established to address several fundamental questions in nuclear and particle physics, including the proton charge radius puzzle, nucleon electromagnetic structure, and the dynamics of quantum electrodynamics and hadronic interactions. The program proceeds in two phases, from elastic scattering to nucleon structure and beyond-Standard-Model searches. The experiment is expected to determine the proton charge radius with a precision of approximately 1.0\% using elastic muon-proton scattering. It will also perform systematic measurements of the proton electromagnetic form factors with both $\mu^+$ and $\mu^-$ beams, enabling precise studies of two-photon exchange effects and stringent tests of quantum electrodynamics. Beyond elastic scattering, LUNE will investigate TMD, gravitational form factors, and nuclear charge radii, providing new insights into the 3D structure of nucleons and nuclei. The experiment will further address important topics including Coulomb-distortion corrections, nuclear medium effects, and possible signatures of physics beyond the Standard Model. This white paper presents the scientific motivation, detector concept, expected performance, and long-term strategy of LUNE.

hep-ex↗

arXiv2026

Hadronic tensor in lattice gauge theories by quantum computing

The hadronic tensor encodes crucial information regarding the internal structure of hadrons, reflecting the non-perturbative features of quantum chromodynamics (QCD). In this work, we directly compute the hadronic tensor within (1+1)-dimensional $\rm U(1)$ and $\rm SU(2)$ gauge theories by evaluating real-time current-current correlation functions. Utilizing quantum algorithms executed on classical hardware, we demonstrate that the hadron form factors for both meson and baryon states can be reliably extracted from the hadronic tensor. Our methodology is validated by strong agreement with both direct calculation and exact diagonalization of the form factors.

hep-ph↗

arXiv2026

$D^0$-$D_s^+$ Elliptic-Flow Splitting under Event-Shape Engineering: A Probe of Sequential Charm Hadronization

Recent work has proposed sequential hadronization of open-charm hadrons in the quark-gluon plasma, wherein more tightly bound species such as $D_s^+$ form earlier near $1.2 T_c$ and $D^0$ forms later at $T_c$. That work showed that this mechanism naturally reverses the sign of the $D^0-D_s^+$ elliptic-flow splitting relative to the conventional simultaneous baseline. In this work, we demonstrate that event-shape engineering (ESE) provides a sharper discrimination between the two pictures than inclusive measurements alone. By selecting large-$q_2$ and small-$q_2$ events in 0--10\% and 30--50\% centrality classes in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV, we show that the geometry-driven enhancement of charm-meson $v_2$ can be separated from the hadronization-time response: the positive $\Delta v_2(D^0-D_s^+)$ in the sequential scenario grows systematically with $q_2$, while the corresponding response slope $\chi$ reveals a species-dependent hierarchy $\chi(D^0) > \chi(D_s^+)$ that is robust against the overall flow normalization and absent in the simultaneous baseline. In the simultaneous case, the splitting is near zero or negative and does not follow the same geometry scaling. Notably, the semi-central 30--50\% class emerges as the optimal window, because the non-monotonic interplay between QGP lifetime and initial eccentricity maximizes the late-stage flow conversion. The $q_2$ ratios of the $D_s^+/D^0$ yield ratio remain close to unity, confirming that the splitting is a dynamical flow effect rather than a chemical yield modification. These results establish $\Delta v_2(D^0-D_s^+)$ and the response slope $\chi$ under ESE as complementary differential probes of the space-time structure of charm hadronization near the QCD transition temperature.

hep-ph↗

arXiv2026

Attractors in a Generalized Relativistic Second Order Spin Hydrodynamics

We investigate the attractor of spin density in relativistic spin hydrodynamics using Zubarev's non-equilibrium statistical operator formalism in the spin probe limit. We derive the (0+1)D Bjorken flow equations and the associated attractor equation while retaining second order gradient corrections in the relevant relaxation constitutive equations including couplings associated with nonlinear response and nonlocal memory effects. We analyze the early time fixed point structure and analytically determine the early time attractor solution, thereby clarifying branch selection and the role of different dynamical corrections. We find that source-like driving terms modify the leading correction to the attractor solution without changing the fixed point structure, whereas self feedback terms involving the rotational stress tensor modify the dominant balance and modify the early time fixed point structure. We further study the late time asymptotic behavior in the conformal limit and show that the newly added terms affect the first subleading asymptotics without changing the leading late time branches. These results provide a unified picture of early and late time attractor dynamics in the conformal limit.

hep-ph↗

arXiv2026

System-size dependence of the $D^0$--$D_s^+$ flow splitting from early $D_s^+$ formation at $\sqrt{s_{NN}} = 5.36$~TeV

We investigate the elliptic-flow splitting between prompt $D^0$ and $D_s^+$ mesons within a heavy-quark transport framework with sequential hadronization, in which $D_s^+$ forms at $1.2\,T_c$ and $D^0$ at $T_c$. We present predictions for the $p_T$-differential $v_2$ and $D_s^+/D^0$ yield ratio in O--O $0$--$20\%$ collisions at $\sqrt{s_{NN}} = 5.36$~TeV, where preliminary ALICE data are available. The sequential scenario reproduces the observed $v_2(D^0) > v_2(D_s^+)$ ordering and predicts an enhanced $D_s^+/D^0$ ratio at low $p_T$, whereas a simultaneous baseline yields the opposite ordering. Decomposing the hadronic splitting into its partonic components, we show that the $v_2$ ordering is driven by the late-stage flow accumulated by $D^0$-parent charm quarks during the $1.2\,T_c \to T_c$ interval, with hadronic rescattering essential to preserve the signal in small systems. A systematic scan across nine collision configurations spanning O--O and Pb--Pb centralities reveals a universal linear scaling between the hadronic splitting and the partonic flow increment accumulated during this window. This establishes the $D^0$--$D_s^+$ flow splitting as a hadronization chronometer of the QGP at $\sqrt{s_{NN}} = 5.36$~TeV.

hep-ph↗

arXiv2025

Substructure grooming of inclusive and photon-tagged jets in heavy-ion collisions

Jet substructure provides a powerful probe of partonic interactions within the quark-gluon plasma (QGP) in heavy-ion collisions. In this paper, we present a systematic theoretical study of the groomed substructures for both inclusive jets and photon-tagged jets ($\gamma+$jets) utilizing the Dynamical and Soft-Drop Grooming algorithms in PbPb collisions by employing the SHELL transport model. Our theoretical calculations exhibit a suppression at high $k_{\rm T,g}$, the relative transverse momentum between the two subjets in the groomed substructure, consistent with the recent ALICE measurements. We show that the suppression of high $k_{\rm T,g}$ arises from the combined effects of the reduction of the subleading subjet transverse momentum due to partonic energy loss and the narrowing of the groomed jet radius $R_g$ induced by selection bias. Our findings demonstrate that no enhancement is observed at high $k_{\rm T,g}$, even in the complete absence of selection bias. Furthermore, we propose that the broadening of $R_g$ in photon-tagged jets, which are less susceptible to selection bias compared to inclusive jets, provides relatively direct evidence of the jet substructure broadening. Our analysis reveals that the $R_g$ broadening becomes more pronounced as the jet radius increases, where the medium-induced gluon radiation plays a dominant role in driving such broadening. In particular, we find that as the jet radius increases, the Soft Drop grooming algorithm exhibits a better resolving power for the contribution of the medium response to the jet substructure broadening.

hep-ph↗

arXiv2025

Unraveling the neutron skin thickness through jet charge in deep inelastic scattering

The neutron skin thickness in neutron-rich nuclei has traditionally been measured using elastic fixed target electron-nucleus scattering since the 1970s. In this paper, we propose a novel probe of the neutron skin thickness through deep inelastic scattering in electron-ion collisions, leveraging the intrinsic correlation between final-state jet charge distribution and initial-state partonic distributions in nucleons. Specifically, we demonstrate the sensitivity of jet charge distribution to the neutron skin thickness in $e$+Pb collisions with varying centralities, and in isobar collisions of $e$+Ru and $e$+Zr. We predict a strong suppression of positive jet charge distribution and an enhancement for negative jet charge distribution in peripheral electron-ion collisions, revealing the neutron skin effect. This proposal can also be extended to photon and Z-boson tagged jet charge distribution in proton-nucleus collisions at the Large Hadron Collider, providing an alternative access to neutron skin thickness.

hep-ph↗

arXiv2024

Quantum computing of chirality imbalance in SU(2) gauge theory

We implement a variational quantum algorithm to investigate the chiral condensate in a 1+1 dimensional SU(2) non-Abelian gauge theory. The algorithm is evaluated using a proposed Monte Carlo sampling method, which allows the extension to large qubit systems. The obtained results through quantum simulations on classical and actual quantum hardware are in good agreement with exact diagonalization of the lattice Hamiltonian, revealing the phenomena of chiral symmetry breaking and restoration as functions of both temperature and chemical potential. Our findings underscore the potential of near-term quantum computing for exploring QCD systems at finite temperature and density in non-Abelian gauge theories.

hep-ph↗

arXiv2024

The Boundary Effect of QGP Droplet and Self-similarity Effect of Hadrons on QGP-hadron Phase Transition

We investigate the boundary effect of QGP droplet and self-similarity effect of hadrons on QGP-hadron phase transition. In intermediate or low energy collisions, when the transverse momentum is below QCD scale, QGP cannot be produced. However, if the transverse momentum fluctuates to a relatively large value, small scale QGP droplet is produced. The modified MIT bag model with multiple reflection expansion method is employed to study the QGP droplet with the curved boundary effect. It is found that the energy density, entropy density and pressure of QGP with the influence are smaller than those without the influence. In hadron phase, we propose Two-Body Fractal Model (TBFM) to study the self-similarity structure, arising from the resonance, quantum correlation and interaction effects. It is observed that energy density, entropy density and pressure increase due to the self-similarity structure. We calculate the transverse momentum spectra of pions with the self-similarity structure influence, showing a good agreement with the experimental data. Considering both the boundary effect and self-similarity structure influence, our model predicts an increase in the transition temperature compared to scenarios without these two effects in HIAF energy region $2.2\sim 4.5 \,\text{GeV}$.

hep-ph↗

arXiv2024

Probing the mass effect of heavy quark jets in high-energy nuclear collisions

The production of heavy quark (HQ) jets provides a new arena to address the mass effect of jet quenching in heavy-ion physics. This paper presents a theoretical study of HQ jet yield suppression in Pb+Pb collisions at the LHC and focuses on the energy loss of HQ jets produced by different mechanisms. The p+p baseline is carried out by the SHERPA generator, and the jet-medium interactions are described by the SHELL transport model, which considers the elastic and inelastic partonic energy loss in the quark-gluon plasma (QGP). In p+p collisions, our numerical results indicate that the HQ jets from gluon splitting ($g \rightarrow Q$-jet) give the dominant contribution at high $p_T$, and it shows more dispersive structures than the HQ-initiated one ($Q \rightarrow Q$-jet). In nucleus-nucleus collisions, our calculations are consistent with the inclusive and b-jet $R_{AA}$ recently measured by the ATLAS collaboration, which suggests a remarkable manifestation of the mass effect of jet energy loss. As a result of the dispersive substructure, the $g \rightarrow Q$-jet will lose more energy than the $Q \rightarrow Q$-jet in the QGP. Due to the significant contribution of $g \rightarrow c$-jet, the $R_{AA}$ of c-jet will be comparable or even smaller than that of inclusive jet. To experimentally distinguish the $g \rightarrow Q$-jet and $Q \rightarrow Q$-jet, we propose the event selection strategies based on their topological features and test the performances. By isolating the $c \rightarrow c$-jet and $b \rightarrow b$-jet, the jets initiated by heavy quarks, we predict that the order of their $R_{AA}$ are in line with the mass hierarchy of energy loss. Future measurements on the $R_{AA}$ of $Q \rightarrow Q$-jet and $g \rightarrow Q$-jet will provide a unique chance to test the flavor/mass dependence of energy loss at the jet level.

hep-ph↗

arXiv2024

Hyperon Polarization from the Vortical Fluid in Low Energy Nuclear Collisions

In 2017, STAR Collaboration reported the measurements of hyperon global polarization in heavy ion collisions, suggesting the subatomic fireball fluid created in these collisions as the most vortical fluid. There remains the interesting question: at which beam energy the truly most vortical fluid will be located. In this work we perform a systematic study on the beam energy dependence of hyperon global polarization phenomenon, especially in the interesting $\hat{O}(1\sim 10)\ \rm GeV$ region. We find a non-monotonic trend, with the global polarization to first increase and then decrease when beam energy is lowered from $27~\rm GeV$ down to $3~\rm GeV$. The maximum polarization signal has been identified around $\sqrt{s_{NN}} = 7.7~\rm GeV$, where the heavy ion collisions presumably create the most vortical fluid. Detailed experimental measurements in the $\hat{O}(1\sim 10)\ \rm GeV$ beam energy region are expected to test the prediction very soon.

nucl-th↗

arXiv2024

Responses of quark-antiquark interaction and heavy quark dynamics to magnetic field

We investigate the impact of the magnetic field generated by colliding nuclei on heavy quark-antiquark interactions and heavy quark dynamics in the quark-gluon plasma (QGP). By means of hard-thermal-loop resummation technique combined with dimension-two gluon condensates, the static heavy quark potential and heavy quark momentum diffusion coefficient, which incorporate both perturbative and non-perturbative interactions between heavy quarks and the QGP medium, are computed beyond the lowest Landau level approximation. We find that the imaginary part of the heavy quark potential in the magnetic field exhibits significant anisotropy. Specifically, the absolute value of the imaginary part is larger when the quark-antiquark separation is aligned perpendicular to the magnetic field direction, compared to when it is aligned parallel to the magnetic field direction. The heavy quark momentum diffusion coefficient in the magnetized QGP medium also becomes anisotropic. As the temperature rises, the influence of higher Landau levels becomes increasingly significant, resulting in a decrease in the anisotropy ratio of the heavy quark momentum diffusion coefficient to values even below 1. At sufficiently high temperatures, this ratio ultimately approaches 1. The non-perturbative interactions are indispensable for understanding heavy quark dynamics in the low-temperature region. We also study the response of viscous quark matter to the magnetic field and explore its implications for heavy quark potential, thermal decay widths of quarkonium states, as well as heavy quark momentum diffusion coefficient.

hep-ph↗

arXiv2024

Flavor dependence of jet quenching in heavy-ion collisions from a Bayesian analysis

We investigate the flavor dependence of jet quenching, by performing a systematic analysis of medium modifications on the inclusive jet, $γ$+jet, and $b$-jet in Pb+Pb collisions at the LHC. Our results from MadGraph+PYTHIA exhibit excellent agreement with experimental measurements of the inclusive jet, $γ$+jet and $b$-jet simultaneously in p+p collisions. We then utilize a Bayesian data-driven method to extract systematically the flavor-dependent jet energy loss distributions from experimental data, where the gluon, light quark and $b$-quark initiated energy loss distributions are well constrained and satisfy the predicted flavor hierarchy of jet quenching, i.e. $\langle ΔE_g \rangle > \langleΔE_q\rangle > \langleΔE_b\rangle$. It is shown that the quark-initiated jet energy loss distribution shows weaker centrality and $p_\text{T}$ dependence than the gluon-initiated one. We demonstrate the impacts of the slope of initial spectra, color-charge as well as parton mass dependent jet energy attenuation on the $γ/b$-jet suppression observed in heavy-ion collisions.

hep-ph↗

arXiv2024

Scattering Amplitude from Quantum Computing with Reduction Formula

Utilizing the Lehmann-Symanzik-Zimmermann reduction formula, we present a new general framework for computing scattering amplitudes in quantum field theory with quantum computers in a fully nonperturbative way. In this framework, one only has to construct one-particle states of zero momentum, and no wave packets of incoming particles are needed. The framework is able to incorporate scatterings of bound states, and is ideal for scatterings involving a small number of particles. We expect this framework to have particular advantages when applied to exclusive hadron scatterings. As a proof of concept, by simulations on classical hardware, we demonstrate that in the one-flavor Gross-Neveu model, the fermion propagator, the connected fermion four-point function, and the propagator of a fermion-antifermion bound state obtained from our proposed quantum algorithm have the desired pole structure crucial to the implementation of the Lehmann-Symanzik-Zimmermann reduction formula.

hep-ph↗

arXiv2023

The Spectrum of Low-$p_T$ $J/ψ$ in Heavy-Ion Collisions in a Statistical Two-Body Fractal Model

We establish a statistical two-body fractal (STF) model to study the spectrum of $J/ψ$. $J/ψ$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/ψ$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effects in the fitted parameters. Here, we study the issue from a new point of view by analyzing the fact that all three effects induce a self-similarity structure, involving a $J/ψ$-$π$ two-meson state and a $J/ψ$, $π$ two-quark state, respectively. We introduce modification factor $q_{TBS}$ and $q_2$ into the probability and entropy of charmonium. $q_{TBS}$ denotes the modification of self-similarity on $J/ψ$, $q_2$ denotes that of self-similarity and strong interaction between \emph{c }and $\bar{c}$ on quarks. By solving the probability and entropy equations, we derive the values of $q_{TBS}$ and $q_2$ at various collision energies and centralities. Substituting the value of $q_{TBS}$ into distribution function, we successfully obtain the transverse momentum spectrum of low-$p_T$ $J/ψ$, which demonstrates good agreement with experimental data. The STF model can be employed to investigate other mesons and resonance states.

hep-ph↗

arXiv2023

Exploring Light-Cone Distribution Amplitudes from Quantum Computing

Light-cone distribution amplitudes (LCDAs) are essential nonperturbative quantities for theoretical predictions of exclusive high-energy processes in quantum chromodynamics (QCD). We demonstrate the prospect of calculating LCDAs on a quantum computer by applying a recently proposed quantum algorithm, with staggered fermions, to the simulation of the LCDA in the (1+1)-dimensional Nambu-Jona-Lasinio (NJL) model on classical hardware. The agreement between the result from the classical simulation of the quantum algorithm and that from exact diagonalization justifies the proposed quantum algorithm. We find that the resulting LCDA in the NJL model exhibits features shared with the LCDAs obtained from QCD.

hep-ph↗

arXiv2023

Unraveling Gluon Jet Quenching through $J/ψ$ Production in Heavy-Ion Collisions

Jet quenching has long been regarded as one of the key signatures for the formation of quark-gluon plasma in heavy-ion collisions. Despite significant efforts, the separate identification of quark and gluon jet quenching has remained as a challenge. Here we show that $J/ψ$ in high transverse momentum ($p_\text{T}$) region provides a uniquely sensitive probe of in-medium gluon energy loss since its production at high $p_\text{T}$ is particularly dominated by gluon fragmentation. Such gluon-dominance is first demonstrated for the baseline of proton-proton collisions within the framework of leading power NRQCD factorization formalism. We then use the linear Boltzmann transport model combined with hydrodynamics for the simulation of jet-medium interaction in nucleus-nucleus collisions. The satisfactory description of experimental data on both nuclear modification factor $R_{\text{AA}}$ and elliptic flow $v_2$ reveals, for the first time, that the gluon jet quenching is the driving force for high $p_\text{T}$ $J/ψ$ suppression. This novel finding is further confirmed by the data-driven Bayesian analyses of relevant experimental measurements, from which we also obtain the first quantitative extraction of the gluon energy loss distribution in the quark-gluon plasma.

hep-ph↗