The existence of neutron stars provide us with a challenge and a
possibility to study strong interaction, too. At the center of
neutron stars the densities can reach 6-8 times the normal nuclear densities,
and these densities cannot be studied in terrestrial experiments.
Therefore, it provides us with constraints for the properties of the cold,
dense strongly interacting matter.
The...
The QGP fireball is a temporally fast-evolving and spatially highly nonuniform system. Instantaneously, the spatial temperature gradients are huge and will have significant influence on the spatial distribution of QCD order parameter and its correlations, but related studies are inadequate.
Based on the local equilibrium assumption and the Markov assumption, we will discuss the phase...
In this talk, I will present the application of machine learning in holographic QCD. By incorporating the equation of state and baryon number susceptibility data, we leverage machine learning techniques to construct a holographic model capable of predicting the location of the critical endpoint (CEP). Furthermore, we enhance the model using Bayesian inference, providing a refined CEP...
With the new heavy-ion collision facilities at FAIR (CBM) and HIAF (CEE+) being nearly completed, the experimental researches in the high baryon density region of QCD phase diagram are entering the precision physics era. There is in turn a great demand on the first-principles QCD computations in theory, in order to have a clear understanding on the observational signatures in experiments.
To...
To better understand recent predictions on the moat regime of quantum chromodynamics (QCD) matter, this paper extends the previous work within the two-flavor quark-meson (QM) model to the more realistic 2+1 flavor Polyakov-quark-meson (PQM) model. Mainly, two effects are further taken into account: strange quark and confinement coded through Polyakov loop. Model parameters are chosen to...
The quark anomalous magnetic moments (AMMs) are investigated in a 2-flavor low-energy effective theory within the functional renormalization group (FRG) approach under an external magnetic field. The Schwinger formalism is adopted for quark propagators, and Fierz-complete four-quark scatterings are self-consistently included through the renormalization group flows. We find that the quark AMMs...
Searching for the QCD critical end point is one of the most important topic. In this work, we present the study of net-proton cumulants and factorial cumulants in Au+Au collisions from the RHIC-STAR Beam Energy Scan Phase-II program. Careful event and track selections, with efficiency and systematic corrections, yield high-precision results across energies, centralities, and kinematic windows....
The ALICE collaboration published the first measurement of the skewness and kurtosis of mean pT fluctuations, which can constrain the initial state of ultra-relativistic nuclear collisions. In this paper, we investigate the higher-order mean pT fluctuations using a multiphase transport model for three different collision systems: pp collision at 5.02 TeV, Pb+Pb collision at 5.02 TeV and Xe+Xe...
The medium modification of jet substructure in hot and dense nuclear matter has garnered significant interest from the heavy-ion physics community in recent years. Measurements of inclusive jets show an angular narrowing in nucleus-nucleus collisions, while recent CMS results for photon-tagged jets ($\gamma$+jets) suggest evidence of broadening. In this study, we conduct a theoretical analysis...
The chromomagneto monopoles, an excitation of the non-Abelian gauge field that carries chromomagnetic charge, are believed to be important in explaining confinement in vacuum and the strong coupling nature around the confinement-deconfinement transition temperature ($T_c$). The chromomagneto monopoles have been found to be a solution to the long-standing puzzle that one cannot simultaneously...
We present a comprehensive study of multiplicity distributions in QCD jets at the LHC. Our analysis combines pQCD calculations within the Double Logarithmic Approximation (DLA) and modified DLA (MDLA), together with comparisons to ATLAS data and PYTHIA simulations. We provide the first direct verification of KNO scaling for both quark- and gluon-initiated jets within the DLA framework by...
Recent CMS results reveal that jets with extremely high multiplicity exhibit novel substructure patterns not seen in ordinary jets, including long-range correlations. However, standard Monte Carlo tools struggle to access this regime due to its rarity and complexity. In this work, we develop a theoretical framework to study high-multiplicity jets, incorporating both multiplicity evolution and...
Particles associated with the jet will be deflected from their initial direction due to the scatterings with the thermal partons flowing in the QGP fluid. Such deflections lead to an intra-jet asymmetry coupled with flow, which we can use to extract the properties of the QGP medium. This work calculates the intra-jet asymmetry distribution in both transverse and longitudinal directions and...
This work presents the first theoretical investigation of the medium modification of jet broadening as an event-shape observable in multijet final states due to jet quenching in high-energy nuclear collisions. The partonic spectrum of $pp$ collisions with next-to-leading order (NLO) accuracy at $\sqrt{s_{\mathrm{NN}}} = 5.02$ TeV is provided by the POWHEG+PYTHIA8 event generator, and the...
The talk presents our preliminary estimates of heavy flavor (HF) quark energy loss during its propagation through the non-equilibrated medium formed in minimum bias proton-proton (p+p) collisions at LHC energies. The study is inspired by the ongoing hot debates on whether tiny droplets of Quark-Gluon Plasma can be created in collisions of small systems. In this work, we assume that the...
Particle azimuthal anisotropies inside jets, defined within the momentum plane perpendicular to the jet axis, carry the information of the QCD cascade process for jet formation. In this work, we propose to measure the medium-induced modifications of the elliptic anisotropy inside jets in relativistic heavy-ion collisions to provide novel insight into the jet quenching phenomenon. By simulating...
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....
We study the two-flavor Nambu-Jona-Lasinio model under the rotation and chiral chemical potential μ5. First, the influence of chiral imbalance on the chiral phase transition in the Tpc − ω plane is investigated.
And then by incorporating AMM at the quark level, we find that AMM significantly alters the magnetic field dependence of constituent quark masses, inducing first-order phase...
Exploring the QCD phase transition is one of the most important goals in relativistic heavy-ion collisions. The Beam Energy Scan Program at RHIC has revealed a preliminary non-monotonic behavior of net-proton multiplicity fluctuations with increasing collision energy [1], which is consistent with theoretical predictions [2].
However, the quark-gluon plasma created in relativistic heavy-ion...
We constructed the matrix model under real rotation $\omega$ in a cylinder of radius $R$, with $R \omega<1$ to preserve causality, by using the background field effective theory. Based on this new matrix model, we investigated the confinement/deconfinement phase transition in $SU(3)$ and $SU(2)$ gauge theories. Our results indicate that a phase transition can occur as long as the...
In this work, we propose an effective action for the quark-meson model incorporating all (pseudo)scalar and (axial)vector mesons based on chiral symmetry. Within the framework of the functional renormalization group (FRG), we conduct a systematic study of the model. By deriving and solving the flow equation for the effective potential, we calculate the curvature masses of mesons at finite...
We present a neural network-based quasi-particle model to separate the contributions of chromo-electric and chromo-magnetic gluons. Using dual residual networks, we extract temperature-dependent masses from SU(3) lattice thermodynamic data of pressure and trace anomaly. After incorporating physics regularizations, the trained models reproduce lattice results with high accuracy over $T/T_c \in...
Heavy-ion collisions (HICs) serve as a unique experimental tool for investigating the properties of nuclear matter under extreme conditions in the laboratory. At HIRFL-CSR energies, HICs can produce nuclear matter at densities reaching 2–3 times the normal nuclear saturation density. The HIRFL-CSR External-target Experiment (CEE) is a large-acceptance spectrometer specifically designed to...
We study the first-order phase transition in holographic QCD models with two-flavor and 2+1-flavor matter at finite temperature and chemical potential. Using the holographic bounce solution, we calculate the key parameters governing phase transition dynamics, including the strength parameter $\alpha$, the inverse duration time $\beta/H_*$, and the bubble wall velocity $v_w$. Along the phase...
The critical endpoint (CEP) in the quantum chromodynamics (QCD) phase diagram may act as a thermalization point, drawing non-equilibrium systems toward thermodynamic equilibrium. Using transport and gap equations from the NJL model, we show that QCD matter perturbed by velocity fields near the first-order phase transition line evolves toward the CEP. Simulations confirm this attractor...
In this paper, we consider the Einstein-Maxwell-dilaton holographic model for light quarks with nonzero magnetic field and chemical potential. First, we study the phase diagrams in $T-\mu$ and $T-B$ planes. We observe inverse magnetic catalysis which is consistent with the lattice QCD results. We discuss the influence of the magnetic field and chemical potential on the location of the critical...
We present the first lattice QCD results of quadratic fluctuations and correlations of conserved charges in (2+1)-flavor lattice QCD in the presence of a background magnetic field. The simulations were performed using the Highly Improved Staggered Quarks with physical pion mass $m_\pi$ = 135 MeV on $N_\tau=8$ and 12 lattices. We find that the correlation between net baryon number and electric...
