Using the TRENTo-3D initial condition model coupled with (3+1)-dimensional CLVisc hydrodynamic simulations, we systematically investigate the left-right splitting of elliptic flow ($\Delta v_{2}$) for soft particles in relativistic heavy-ion collisions. Our study reveals that the final distribution characteristics of $\Delta v_{2}$ are primarily depend on the odd flow harmonics and $v_{2}$...
The Cooling-Storage-Ring External-target Experiment (CEE) at Heavy Ion Research Facility in Lanzhou (HIRFL) is designed to study the properties of nuclear matter created in heavy-ion collisions at a few hundred MeV/$u$ to 1 GeV/$u$ beam energies, facilitating the research of quantum chromodynamics phase structure in the high-baryon-density region.
Collective flow is one of the most important...
Particle correlations are powerful tools for studying quantum chromodynamics in hadron collisions. In heavy-ion collisions, azimuthal angular correlations probe collective phenomena in hot, dense, nuclear media, such as QGP. The LHCb experiment has the ability to study particle correlations in high-energy hadron collisions at forward rapidity, complementing the results from other experiments....
Shear and bulk viscosities are two key transport coefficients that characterize the fundamental properties of quark-gluon plasma.They quantify the response of the energy-momentum tensor to shear flow and divergent flow,serving as crucial input parameters for the phenomenological and transport models that interpret experimental data, such as the elliptic flow $v_2$.
$\quad$ However,...
The shape and orientation of colliding nuclei play a crucial role in determining the initial conditions of the quark-gluon plasma (QGP), which influence key observables such as anisotropic and radial flow. In this talk, we present the measurements of $v_n$, $p_{\rm T}$ fluctuation, and $v_n-p_{\rm T}$ correlations in isobar-like $^{238}$U+$^{238}$U and $^{197}$Au+$^{197}$Au collisions at...
Understanding the impact of nuclear structure in high-energy nuclear collisions is critical to advancing our knowledge of quark-gluon plasma (QGP) formation. In this study, we investigate the role of nuclear clustering, in particular the alpha-cluster structure in $^{16}\rm{O}$, using anisotropic flow observations from $^{16}\rm{O}+^{16}\rm{O}$ collisions at RHIC energy. Through systematic...
Due to their weak coupling to the strongly interacting matter produced in relativistic heavy-ion collisions, dileptons serve as a sensitive probe of the initial geometry of the colliding nuclei. In this study, we investigate the influence of initial nuclear quadrupole deformation, characterized by the parameter β2, on dilepton production in U+U collisions at √sNN = 193 GeV. The analysis is...
Measurements of collective flow in intermediate size collisions such as OO and NeNe are crucial for understanding the origin of collectivity in small systems and its evolution with collision system size. Furthermore, they are crucial for probing the possible exotic nuclear structure of the nucleus. With data collected by the CMS experiment at the LHC, charged particles $v_{n}$(n=2,3) are...
The early thermalization puzzle—stemming from the unexpectedly early success of hydrodynamics in describing the quark–gluon plasma (QGP)—remains a central open question in relativistic heavy-ion collisions. To address this, we develop a new theoretical framework, the spectral BBGKY hierarchy, which is analytically equivalent to the Liouville equation and preserves time-reversal invariance...
The thermalization of quark-gluon plasma created in heavy-ion collisions is crucial for understanding its behavior as a relativistic fluid and the thermodynamic properties of the Quantum Chromodynamics (QCD). This study investigates the role of fluctuations in the relationship between transverse momentum and particle multiplicity, with a particular focus on their impact on extracting the QCD...
This work presents a comprehensive theoretical investigation into the influence of nuclear microstructure, specifically nucleon-nucleon (NN) correlations and α-cluster structures, on initial-state fluctuations in heavy-ion collisions. By establishing a direct link between nuclear structure details and experimentally measurable observables, we provide crucial theoretical predictions for...
The Drell-S${\rm\ddot{o}ding}$ mechanism, which describes non-resonant pair production via linearly polarized virtual photons in ultra-peripheral heavy-ion collisions, arises from the coherent superposition of contributions from both colliding nuclei. The angular momentum of the system is imprinted in the orbital angular momentum of the produced pair, leading to quantum entanglement between...
Significant progress, particularly in holography, has clarified how rapidly two-point functions hydrodynamize after a quench. Motivated by non-Gaussian observables relevant to the QCD critical-point program, we ask: how do higher-point functions hydrodynamize relative to two-point functions? We propose two conjectures that organize the ordering and scaling of hydrodynamization times across...
Event-by-event mean transverse momentum fluctuations (<𝑝T>) serve as a sensitive probe of initial state overlap geometry and energy density fluctuations in relativistic heavy-ion collisions. We present a systematic investigation of <𝑝T> fluctuations in Au+Au collisions at 3.0–19.6 GeV, examining their centrality and energy dependence with the framework of an improved multiphase transport...
Onset of hydrodynamics in the hot medium created in relativistic heavy-ion collisions is a crucial theoretical question. Addressing this problem in a first-principle manner, requires a real-time, non-perturbative simulation of a large scale quantum system, as hydrodynamic behavior emerges only when approaching the continuum limit. The exponentially large Hilbert space of quantum states...
The early-stage thermalization of the Quark-Gluon Plasma (QGP) is important process in high energy collision. However, our understanding of thermalization of isolated quantum systems in this stage stills remains limited. This talk aims to explore QGP thermalization from the perspective of entropy in isolated many-body quantum systems. To solve the long-standing problem of the entropy paradox...
Using the three-dimensional kinetic Ising model with Metropolis algorithm, we calculate the free energy in the whole phase boundary, particularly near the first phase transition line (1st-PTL). The results show that along the 1st-PTL, as the temperature decreases, the energy barrier between the two coexisting phases diverges. This results in more difficulty to reach the equilibrium, i.e.,...
One of the central goals of the RHIC Beam Energy Scan is to identify the transition from ordinary hadronic matter to the Quark–Gluon Plasma (QGP). Elliptic flow ($v_2$), which reflects the azimuthal anisotropy of particle emission, serves as a sensitive probe of collectivity and the active degrees of freedom of the medium. Over the past two decades, systematic studies of collectivity across...
Heavy-ion collisions provide a unique environment to study nucleon-nucleon ($N$-$N$) and hyperon-nucleon ($Y$-$N$) interactions, as well as the production mechanisms and structure of light (hyper)nuclei. Two-particle correlations at small relative momenta serve as a powerful tool, carrying rich information about the space-time evolution of the particle-emitting source and the effects of...
Dibaryons, exotic states composed of six quarks, have long been a subject of interest in understanding the strong interaction beyond conventional hadrons. Among these, strange dibaryons, which contain strange quarks, offer an important role of studying the hyperon-nucleon ($YN$) and hyperon-hyperon ($YY$) interactions . Of particular interest are the spin-0 $H$ ($S$ = -2) and the spin-2...
Directed flow $v_1$ has been used to probe early dynamics in high-energy nuclear collisions. The vector meson $\phi(s \overline{s})$, with a mass comparable to that of light baryons, exhibits a small interaction cross section with other hadrons. Therefore, the measurement of $\phi$-meson directed flow $v_1$ provides clean access to the early collision dynamics and the production mechanisms of...
We perform 2+1D simulations of anisotropic hydrodynamics (aHydro) under boost-invariant and
conformal conditions. Comparing both aHydro and traditional hydrodynamics to kinetic theory
in the relaxation-time approximation as the underlying microscopic theory, we show that aHydro
provides a superior description of the evolution across a wide range of opacity, effectively extending
the...
The differential cross section of the diffractive vector meson production in electron proton deeply inelastic scattering is considered to be one of the most promising observables to probe the spatial structure of the proton and the QCD dynamics in the high energy limit. In this work, we investigate the dependence of the differential cross section of vector meson production on the position...
Nuclear modifications to parton distribution functions provide an essential baseline for disentangling final-state nuclear matter effects in high-energy nuclear collisions. However, determining the explicit form of the modification factors $r^{\textrm{A}}_i(x,Q^2)$ through global analyses remains challenging, partly due to their complex relationships with observables. In this talk, we...
Fragmentation functions (FFs) are crucial non-perturbative inputs in quantum chromodynamics (QCD) for predicting hadron production cross sections in high-energy scattering processes. In this talk, we present recent progress on global fits of FFs by the Non-perturbative Physics Collaboration (NPC). Our analyses incorporate a comprehensive set of precision measurements, including data from the...
We propose a novel strategy to systematically isolate the nucleon’s intrinsic non-perturbative three-dimensional structure by employing 0-jettiness to suppress initial-state radiation in transverse momentum-dependent (TMD) observables. Applying this method to transverse single spin asymmetries (SSAs) in W$^±$ and Z$^0$ boson production at RHIC, we demonstrate a substantial enhancement of...
The fragmentation process has been proposed as a possible origin of the transverse $\Lambda$ polarization, described by polarizing fragmentation functions (pFFs). In $pp$ collisions, this mechanism can be studied by measuring the $\Lambda$ polarization within jets. We present the first measurement of the transverse polarization of $\Lambda$/$\overline{\Lambda}$ hyperons relative to the jet...
In high-energy scattering processes, the partonic density exhibits a crucial phenomenon, primarily dominated by gluonic density at the small-$x$ region. The partonic density increases rapidly with the decrease in Bjorken-$x$ owing to gluon splitting, while the overlapping gluons begin to recombine and become prevalent at high-density. This results in a balance between splitting and...
