Ankit Anand, Souvik Paul, Sarthak Satapathy, Sabyasachi Ghosh
We have studied the collisional time and relaxation time of a QGP(Quark-Gluon Plasma) by parameterizing them by temperature. From this parameterization we have obtained the decay rate parameterized by temperature which further helps us to calculate and compare the shear viscosity to entropy density ratio of a QGP with the KSS(Kovtun-Son-Starinets) result.
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The transverse momentum distribution of identified hadrons from recent years are analyzed within the thermodynamically consistent formulation of non-extensive statistics. A wide range of center-of-mass energies and average event multiplicities are studied for various hadron species. We demonstrate that the average event multiplicity is a key variable in the study of high-energy collisions and a smooth transition in the description from small to large systems is possible. For this purpose the non-extensive statistical approach is more than appropriate. The validity of the non-extensive descript…
The collisional energy gain of a heavy quark due to chromo-electromagnetic field fluctuations in a quark-gluon plasma is investigated. The field fluctuations lead to an energy gain of the quark for all temperatures and velocities. The net effect is a reduction of the collisional energy loss by 15-40% for parameters relevant at RHIC energies.
We calculate the collisional energy loss suffered by a heavy (charm) quark created at a finite time within a Quark Gluon Plasma (QGP) in the classical linear response formalism as in Peigne {\it et al.} \cite{peigne}. We pay close attention to the problem of formulating a suitable current and the isolation of binding and radiative energy loss effects. We find that unrealistic large binding effects arising in previous formulations must be subtracted. The finite time correction is shown to be important only for very short length scales on the order of a Debye length. The overall energy loss is s…
We study the \textit{non-ideal} effects arising due to viscosity (both bulk and shear), equation of state ($ε\neq 3P$) and cavitation on thermal dilepton production from QGP at RHIC energies. We calculate the first order corrections to the dilepton production rates due to shear and bulk viscosities. Ignoring the cavitation can lead to a wrong estimation of dilepton spectra. We show that the shear viscosity can enhance the thermal dilepton spectra whereas the bulk viscosity can suppress it. We present the combined effect of bulk and shear viscosities on the dilepton spectra.
In this article, we will briefly review the recent progress on hydrodynamic modeling and the extraction of the quark-gluon plasma (QGP) specific shear viscosity with an emphasis on results obtained from the hybrid model VISHNU that couples viscous hydrodynamics for the macroscopic expansion of the QGP to the hadron cascade model for the microscopic evolution of the late hadronic stage.
With the new viscous hydrodynamic + hadron cascade hybrid code VISHNU, a rather precise (O(25%)) extraction of the QGP shear viscosity (eta/s)_QGP from heavy-ion elliptic flow data is possible if the initial eccentricity of the collision fireball is known with <5% accuracy. At this point, eccentricities from initial state models differ by up to 20%, leading to an O(100%) uncertainty for (eta/s)_QGP. It is shown that a simultaneous comparison of elliptic and triangular flow, v_2 and v_3, puts strong constraints on initial state models and can largely eliminate the present uncertainty in (eta/s)…
The chromo-electromagnetic field fluctuations in the quark-gluon plasma (QGP) play an important role as these field fluctuations result energy gain of heavy quarks. We consider these fluctuations and evaluate the transport coefficients, e.g., drag and diffusion coefficients of charm quarks and shear viscosity to entropy density ratio ($η/s$) of the QGP. We find a significant effect of such fluctuations on the transport coefficients. These fluctuations cause a reduction of the drag and diffusion coefficients. We also observe that the shear viscosity to entropy density ratio of the QGP is closer…
We study the heavy quark scattering on partons of the quark gluon plasma (QGP) being especially interested in the collisional (elastic) scattering processes of heavy quarks on quarks and gluons. We calculate the different cross sections for perturbative partons (massless on-shell particles in the vacuum) and for dynamical quasi-particles (off-shell particles in the QGP medium as described by the dynamical quasi-particles model "DQPM") using the leading order Born diagrams. Our results show clearly the effect of a finite parton mass and width on the perturbative elastic $(q(g) Q \rightarrow q (…
We investigate the shear viscosity of thermalized photons in the quark gluon plasma (QGP) at weak coupling and $\mathcal{N}=4$ super Yang-Mills plasma (SYMP) at both strong and weak couplings. We find that the shear viscosity due to the photon-parton scattering up to the leading order of electromagnetic coupling is suppressed when the coupling of the QGP/SYMP is increased, which stems from the blue-shift of the thermal-photon spectrum at strong coupling. In addition, the shear viscosity rapidly increases near the deconfinement transition in a phenomenological model analogous to the QGP.
In this study we evaluate the dynamical collisional energy loss of heavy quarks, their interaction rate as well as the different transport coefficients (drag and diffusion coefficients, $\hat{q}$, etc). We calculate these different quantities for i) perturbative partons (on-shell particles in the vacuum with fixed and running coupling) and ii) for dynamical quasi-particles (off-shell particles in the QGP medium at finite temperature $T$ with a running coupling in temperature as described by the dynamical quasi-particles model). We use the perturbative elastic $(q(g) Q \rightarrow q (g) Q)$ cro…
We consider QCD at temperatures T near Tc, where the theory deconfines. We distinguish between a "complete" Quark Gluon Plasma (QGP), where the vacuum expectation value of the renormalized Polyakov loop is near unity, essentially constant with T, and the "semi"-QGP, where the loop changes strongly with T. Lattice simulations indicate that in QCD, there is a semi-QGP from below Tc to a few times that. Using a semi-classical model, we compute the shear viscosity, eta, to leading order in perturbation theory. We find that near Tc, where the expectation value of the Polyakov loop is small, that et…
We calculate two transport coefficients -- the shear viscosity over entropy ratio $η/s$ and the ratio of the electric conductivity to the temperature $σ_0/T$ -- of strongly interacting quark matter within the extended $N_f=3$ Polyakov Nambu-Jona-Lasinio (PNJL) model along the crossover transition line for moderate values of baryon chemical potential $0 \leq μ_B \leq 0.9$ GeV as well as in the vicinity of the critical endpoint (CEP) and at large baryon chemical potential $μ_B=1.2$ GeV, where the first-order phase transition takes place. The evaluation of the transport coefficients is performed …
We study the viscosity and thermodynamic properties of QGP at RHIC by employing the recently extracted equilibrium distribution functions from two hot QCD equations of state of $O(g^5)$ and $O(g^6\ln(1/g))$ respectively. After obtaining the temperature dependence of energy density, and entropy density, we focus our attention on the determination of shear viscosity for a rapidly expanding interacting plasma, as a function of temperature. We find that interactions significantly decrease the shear viscosity. They decrease the viscosity to entropy density ratio, $η/{\mathcal S}$ as well.
The bottom quark transport coefficients, i.e., drag and diffusion coefficients, have been studied for the collisional and soft gluon radiative processes within the viscous QCD medium. The thermal medium effects are incorporated using the effective fugacity quasiparticle model (EQPM). Both the shear and bulk viscous effects at leading order are embedded through the near-equilibrium distribution functions of the quark-gluon plasma (QGP) constituent quasiparticles. The transport coefficients' dependence on the bottom quark's initial momentum and QGP temperature has been investigated. The relative…
In the framework of the Mueller-Israel-Stewart theory of dissipative fluid dynamics, we have studied the space-time evolution of a QGP fluid. For simplicity, we have considered shear viscosity only and neglected bulk viscosity and heat conductivity. Shear viscosity opposes the expansion and cooling of the fluid. As a result, the lifetime of the fluid is extended. We also find that the parton $p_T$ distribution is considerably flattened.
Based on the first principle calculation, a Lagrangian for the system describing quarks, gluons, and their interactions, is constructed. Ascribed to the existence of dissipative behavior as a consequence of strong interaction within quark-gluon plasma (QGP) matter, auxiliary terms describing viscosities are constituted into the Lagrangian. Through a "kind" of phase transition, gluon field is redefined as a scalar field with four-vector velocity inherently attached. Then, the Lagrangian is elaborated further to produce the energy-momentum tensor of dissipative fluid-like system and the equation…
Viscous effects of a hot QGP medium in time dependent magnetic field and their phenomenological significance
本文在动力学理论中求解含指数衰减电磁场的相对论Boltzmann方程，首次得到弱场下QGP剪切与体黏度的时间演化，并导出热化时间及η/s、ζ/s以联系实验。
We study the charmonium suppression in different evolutions of quark gluon plasma (QGP) based on the transport model. In the colliding energies of Large Hadron Collider, charmonium final yields are dominated by the recombination of charm and anti-charm quarks in the deconfined phase. Heavy quark diffusions depend less on the shear viscosity of the bulk medium, which makes the J/psi nuclear modification factor in the entire pT bin shows weak dependence on the shear viscosity of QGP. However, charmonium with high transverse momentum pT, can only be produced in the early stage of nuclear collisio…
We investigate the collision energy dependence of shear viscosity over the entropy density ratio $η/s$ in Au+Au collisions at $\sqrt{s_{NN}}=19.6, 39$, and $62.4$ GeV, using Bayesian statistical analysis and Gaussian process emulators to explore the full input parameter space of a transport+hydrodynamics hybrid model. The ratio is found to decrease as a function of collision energy, supporting the results from previous studies performed with the same hybrid model.
Shear Viscosity of Collider-Produced QCD Matter II: Comparing a Multi-Component Chapman-Enskog Framework with AMPT in Full Equilibrium
本研究用多组分Chapman-Enskog框架解析计算QGP的剪切黏度及其与熵密度之比，发现（反）夸克增强黏度且随时间冷却减小，结果与微扰QCD一致，并与AMPT模型对比。
We construct the Liouville operator for the SU(2) classical colored Coulomb plasma (cQGP) for arbitrary values of the Coulomb coupling $Γ=V/K$, the ratio of the mean Coulomb to kinetic energy. We show that its resolvent in the classical colored phase space obeys a hierarchy of equations. We use a free streaming approximation to close the hierarchy and derive an integral equation for the time-dependent structure factor. Its reduction by projection yields hydrodynamical equations in the long-wavelength limit. We discuss the character of the hydrodynamical modes at strong coupling. The shear visc…
We extend our recently advanced model on collisional energy loss of heavy quarks in a quark gluon plasma (QGP) by including radiative energy loss. We discuss the approach and present calculations for PbPb collisions at $\sqrt{s}=2.76 TeV$. The transverse momentum spectra, RAA, and the elliptic flow $v_2$ of heavy quarks have been obtained using the model of Kolb and Heinz for the hydrodynamical expansion of the plasma.
I review recent developments in the phenomenological study of the quark-gluon plasma (QGP) transport properties based on a personal selection of results that were presented at Quark Matter 2019. The constraints on the temperature dependence of QGP shear and bulk viscosity are summarized. I discuss new theory advancements towards more realistic 3D dynamical simulations of heavy-ion collisions at finite baryon density. The challenges and opportunities of applying hydrodynamics to small collision systems are highlighted.
Deciphering the viscous properties and the Bjorken expansion of the QGP medium at finite angular velocity
本研究通过新型弛豫时间近似计算旋转QGP介质的粘性系数，发现角速度增大剪切和体粘度，并加速Bjorken膨胀中的冷却过程。
We have investigated, in the frame work of the transport approach, different aspects of the QGP created in Heavy Ion Collisions at RHIC and LHC energies. The shear viscosity $η$ has been calculated by using the Green-Kubo relation at the cascade level. We have compared the numerical results for $η$ obtained from the Green-Kubo correlator with the analytical formula in both the Relaxation Time Approximation (RTA) and the Chapman-Enskog approximation (CE). From this comparison we show that in the range of temperature explored in a Heavy Ion collision the RTA underestimates the viscosity by about…
Within a covariant parton cascade, we discuss the impact of both finite shear viscosity $η$ and freeze-out dynamics on the elliptic flow generated at RHIC. We find that the enhancement of $η/s$ in the cross-over region of the QGP phase transition cannot be neglected in order to extract the information from the QGP phase. We also point out that the elliptic flow $v_2(p_T)$ for a fluid at $η/s \sim 0.1-0.2$ is consistent with the one needed by quark number scaling drawing a nice consistency between the nearly perfect fluid property of QGP and the coalescence process.
With the QGP opacity computed perturbatively and with the global entropy constraints imposed by the observed dNch/dy~1000, radiative energy loss alone cannot account for the observed suppression of single non-photonic electrons. Collisional energy loss is comparable in magnitude to radiative loss for both light and heavy jets. Two aspects that significantly affect the collisional energy loss are examined: the role of fluctuations, and the effect of introducing a running QCD coupling as opposed to the fixed alpha_s=0.3 used previously.
We investigate the influence of a temperature-dependent shear viscosity over entropy density ratio eta/s on the transverse momentum spectra and elliptic flow of hadrons in ultrarelativistic heavy-ion collisions. We find that the elliptic flow in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC is dominated by the viscosity in the hadronic phase and in the phase transition region, but largely insensitive to the viscosity of the quark-gluon plasma (QGP). At the highest LHC energy, the elliptic flow becomes sensitive to the QGP viscosity and insensitive to the hadronic viscosity.
Bayesian Inference of the Specific Shear and Bulk Viscosities of the Quark-Gluon Plasma at Crossover from $ϕ$ and $Ω$ Observables
本研究利用$\phi$介子和$\Omega$重子作为探针，结合夸克复合模型与黏性冲击波参数化，通过贝叶斯推断首次同时确定了交叉温度下夸克胶子等离子体的比剪切黏度与比体黏度，为QGP输运性质研究提供新途径。
Shear viscosity is a crucial property of QCD matter which determines the collective behavior of the the quark-gluon plasma (QGP) in ultrarelativistic heavy-ion collisions. Extending the near-equilibrium, high-precision investigations in theory and experiment, we take into account the fact that, in a collision, the QGP is generated far from equilibrium. We use the AdS/CFT correspondence to study a strongly coupled plasma and find a significant impact on the ratio of shear viscosity to entropy density, $η/s$. In particular, we investigate the initial heating phase and find a decrease reaching do…
We study the thermal dilepton and photon production from relativistic heavy ion collisions in presence of viscosities by employing the recently developed second order dissipative hydrodynamic formulation estimated within a quasiparticle description of thermal QCD (Quantum Chromo-Dynamics) medium. The sensitivity of shear and bulk viscous pressures to the temperature dependence of relaxation time is analyzed within one dimensional boost invariant expansion of quark gluon plasma (QGP).The dissipative corrections to the phase-space distribution functions upto first order in gradients are obtained…
It has been realized that thermal shear plays a similar role as thermal vorticity in polarizing spin of particles in heavy ion collisions. We point out that shear has a fundamental difference that it leads to particle redistribution in the medium. The redistribution gives rise to an additional contribution to spin polarization through the self-energy, which is parametrically the same order as the one considered so far in the literature. The self-energy contribution is in general gauge dependent. We introduce double gauge links stretching along the Schwinger-Keldysh contour to restore gauge inv…
We have investigated shear viscosity of quark matter in presence of a strong uniform magnetic field background where Nambu-Jona-Lasinio model has been considered to describe the magneto-thermodynamical properties of the medium. In presence of magnetic field, shear viscosity coefficient gets split into different components because of anisotropy in tangential stress of the fluid. Four different components can be merged to two components in limit of strong field, where collisional width of quark becomes much lower than its synchrotron frequency. A simplified contact diagram of quark-quark interac…
It is shown that the acoustic scaling patterns of anisotropic flow for different event shapes at a fixed collision centrality (shape-engineered events), provide robust constraints for the event-by-event fluctuations in the initial-state density distribution from ultrarelativistic heavy ion collisions. The empirical scaling parameters also provide a dual-path method for extracting the specific shear viscosity $(η/s)_\mathrm{QGP}$ of the quark-gluon plasma (QGP) produced in these collisions. A calibration of these scaling parameters via detailed viscous hydrodynamical model calculations, gives $…
This work calculates the first correction to the leading order qq dilepton production rates due to shear viscosity in an expanding gas. The modified rates are integrated over the space-time history of a viscous hydrodynamic simulation of RHIC collisions. The net result is a {\em hardening} of $q_\perp$ spectrum with the magnitude of the correction increasing with invariant mass. We argue that a thermal description is reliable for invariant masses less than $M_{max}\approx(2τ_0 T_0^2)/(η/s)$. For reasonable values of the shear viscosity and thermalization time $M_{max}\approx 4.5$ GeV. Finally,…
We study heavy flavor evolution in the quark-gluon plasma matter and the subsequent hadron gas created in ultrarelativistic heavy-ion collisions. The motion of heavy quarks inside the QGP is described using our modified Langevin framework that incorporates both collisional and radiative energy loss mechanisms; and the scatterings between heavy mesons and the hadron gas are simulated with the UrQMD model. We find that the hadronic interaction further suppresses the $D$ meson $R_\mathrm{AA}$ at high $p_\mathrm{T}$ and enhances its $v_2$. And our calculations provide good descriptions of experime…
With the QGP opacity computed perturbatively and with the global entropy constraints imposed by the observed $dN_{ch}/dy\approx1000$, radiative energy loss alone cannot account for the observed suppression of single non-photonic electrons. We show that collisional energy loss, which previously has been neglected, is comparable to radiative loss for both light and heavy jets and may in fact be the dominant mechanism for bottom quarks. Predictions taking into account both radiative and collisional losses significantly reduce the discrepancy with data. In addition to elastic energy loss, it is cr…
We investigate the energy loss of heavy quarks in the gas, liquid and solid phase of a classical quark-gluon plasma (cQGP) using molecular dynamics simulations. The model consists of massive quarks and gluons interacting as a classical non-relativistic colored Coulomb gas. We show that the electric force decorrelates on a short time scale causing the energy loss to be mostly diffusive and langevin-like in the cQGP. We find that the drag coefficient changes with the heavy quark mass, while the diffusion constant does not. The fractional collisional energy loss is much larger than the leading or…
This manuscript reviews recent theoretical progress on the understanding of the quark gluon plasma in a magnetic field that I presented on the conference Hot Quarks 2016, held at South Padre Island, Texas, USA, 12-17 September 2016. It is shown that, using a holographic bottom-up Einstein-Maxwell-Dilaton model, one can have a good quantitative agreement with Lattice data for QCD equation of state and Polyakov loop with nonzero magnetic field. I also present results for the anisotropic shear viscosity ratio $η_{\parallel}/η_{\perp}$, with the conclusion that $η_{\parallel}<η_{\perp}$ for $B>0$.
Quark-Gluon Plasma (QGP), a QCD state of matter created in ultra-relativistic heavy-ion collisions, has remarkable properties, including, for example, a low shear viscosity over entropy ratio. By detecting the collection of low-momentum particles that arise from the collision, it is possible to gain quantitative insight into the created matter. However, its fast evolution and thermalization properties remain elusive. Only using high momentum objects as probes of QGP can unveil its constituents at different wavelengths. In this review, we attempt to provide a comprehensive picture of what was, …
The strong suppression of heavy quarkonia is a good indicator that one has generated a quark-gluon plasma (QGP) in an ultrarelativistic heavy ion collision. Recent advancements in first principles calculations of the heavy quark potential provide additional insight into this suppression and can be used to further pin down the in-medium properties of the QGP. Realistic 3+1d dissipative hydrodynamical models can be used to simulate the QGP and, with bottomonium as a probe, one can make inferences for the initial temperature of the QGP and other phenomenological parameters such as the shear visco…
We discuss the propagation of heavy quarks (charm and bottom) through the QGP by means of a relativistic Boltzmann transport approach including both collisional and radiative energy loss mechanisms. In particular we investigate the impact of induced gluon radiation by dynamical QCD medium implementing in our transport model a formula for the emitted gluon spectrum calculated in a higher-twist scheme. We notice that in the region of high transverse momentum ($p_T > 10$ GeV) radiative processes play an essential role giving a dominant contribution to the generation of $R_{AA}$ and $v_2$ at momen…
Observable Dependence of Viscous Corrections in QGP: Heavy Quarks and Dileptons in Chapman--Enskog Theory
首次使用梯度展开至二阶的黏性修正计算重夸克输运和热双轻子产生，发现Chapman-Enskog修正显著抑制拖曳力并影响动量扩散，且不同可观测量对动量空间不同区域敏感。
We study the influence of a temperature-dependent shear viscosity over entropy density ratio $η/s$, different shear relaxation times $τ_π$, as well as different initial conditions on the transverse momentum spectra of charged hadrons and identified particles. We investigate the azimuthal flow asymmetries as a function of both collision energy and centrality. The elliptic flow coefficient turns out to be dominated by the hadronic viscosity at RHIC energies. Only at higher collision energies the impact of the viscosity in the QGP phase is visible in the flow asymmetries. Nevertheless, the shear …
Shear Viscosity of Collider-Produced QCD Matter I: AMY Formalism vs. A Modified Relaxation Time Approximation in 0-flavor SU(3) Theory
本文在0味SU(3)理论中比较AMY形式与修正的$q^2$输运加权弛豫时间近似对剪切黏度$η$的计算，证明两者在对撞机产生的QGP相关温度下完全一致，并与Chapman-Enskog方法进行对照。
The drag and diffusion coefficients of charm and bottom quarks propagating through quark gluon plasma (QGP) have been evaluated within the framework of perturbative Quantum Chromodynamics (pQCD). Both radiative and collisional processes of dissipation are included in evaluating these transport coefficients. The dead cone as well as the LPM effects on radiative energy loss of heavy quarks have also been considered. The Fokker Planck equation has been solved to study the dissipation of heavy quarks momentum in QGP. The nuclear suppression factor, $R_{\mathrm AA}$ and the elliptic flow $v_2^{HF}$…
We review the transport properties of the strongly interacting quark-gluon plasma (QGP) created in heavy-ion collisions at ultrarelativistic energies, i.e. out-of equilibrium, and compare them to the equilibrium properties. The description of the strongly interacting (non-perturbative) QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature $T_c$ from lattice QCD. We study the transport coefficients such as the ratio of shear…
Exploring QGP-like phenomena with Charmonia in $p+p$ collisions at $\sqrt{s} = 13$ TeV
本文研究质子-质子碰撞中粲偶素的产额变化，通过引入预平衡态演化、碰撞阻尼、胶子解离与再生等机制，提出这些综合效应可作为探测小碰撞系统中是否存在热化QCD介质的可靠探针。
The specific shear viscosity (eta/s)_QGP of a Quark-Gluon-Plasma (QGP) at temperatures T_c < T < 2T_c is extracted from the centrality dependence of the eccentricity-scaled elliptic flow measured in ultra-relativistic heavy-ion collisions. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find that the eccentricity-scaled elliptic flow is a universal function of charged multiplicity per unit overlap area, (1/S)(dN_ch/dy), that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity. Comparin…
The specific shear viscosity (eta/s)_QGP of quark-gluon plasma (QGP) can be extracted from elliptic flow data in heavy-ion collisions by comparing them with the dynamical model VISHNU which couples a viscous fluid dynamic description of the QGP with a microscopic kinetic description of the late hadronic rescattering and freeze-out stage. A robust method for fixing (eta/s)_QGP from the collision centrality dependence of the eccentricity-scaled charged hadron elliptic flow is presented. The systematic uncertainties associated with this extraction method are discussed, with specific attention to …
We have evaluated the shear viscosity of pion gas taking into account its scattering with the low mass resonances, $σ$ and $ρ$ during propagation in the medium. The thermal width (or collisional rate) of the pions is calculated from $πσ$ and $πρ$ loop diagrams using effective interactions in the real time formulation of finite temperature field theory. A very small value of shear viscosity by entropy density ratio ($η/s$), close to the KSS bound, is obtained which approximately matches the range of values of $η/s$ used by Niemi et al. \cite{Niemi} in order to fit the RHIC data of elliptic flow…
Quenching and flow of charm and bottom quarks via semi-leptonic decay of $D$ and $B$ mesons in Pb+Pb collisions at the LHC
本研究结合CLVisc流体模型、改进的Langevin模型等模拟LHC重离子碰撞中重夸克演化，发现相同扩散系数下粲夸克能量损失强于底夸克。
In 2nd order causal dissipative theory, space-time evolution of QGP fluid is studied in 2+1 dimensions. Relaxation equations for shear stress tensors are solved simultaneously with the energy-momentum conservation equations. Comparison of evolution of ideal and viscous QGP fluid, initialized under the same conditions, e.g. same equilibration time, energy density and velocity profile, indicate that in a viscous dynamics, energy density or temperature of the fluid evolve slowly, than in an ideal fluid. Cooling gets slower as viscosity increases. Transverse expansion also increases in a viscous d…
Shear viscosity and electric conductivity of quark matter at finite temperature and chemical potential with QCD phase transitions
研究有限温度和化学势下夸克物质的剪切粘性和电导率，利用PNJL模型分析QCD相变中输运系数的行为。
Higher derivative holography and temperature dependence of QGP viscosities
针对重离子碰撞揭示的QGP剪切和体黏度温度依赖，研究在五维Einstein-dilaton全息模型中引入高导数修正，并用贝叶斯结果约束dilaton势，同时分析微扰修正与数据的张力及解决方案。
Study of some properties of deconfined matter: Resummed perturbation theory and beyond
本论文运用硬热圈有效理论与Gribov量子化非微扰重求和，系统研究QGP中夸克色散、屏蔽质量、重夸克输运及能量损失等性质。
The large center-of-mass energies available to the heavy-ion program at the LHC and recent experimental advances at RHIC will enable QCD matter at very high temperatures and energy densities, that is, the quark-gluon plasma (QGP), to be probed in unprecedented ways. Fully-reconstructed inclusive jets and the away-side hadron showers associated with electroweak bosons, that is, tagged jets, are among these exciting new probes. Full jet reconstruction provides an experimental window into the mechanisms of quark and gluon dynamics in the QGP which is not accessible via leading particles and leadi…
AdS black holes with planar event horizon topology play a central role in AdS/CFT holography, and particularly in its applications. Generalisations of the known planar black holes can be found by considering the Plebanski--Demianski metrics, a very general family of exactly specified solutions of the Einstein equations. These generalised planar black holes may be useful in applications. We give a concrete example of this in the context of the holographic description of the Quark-Gluon Plasma (QGP). We argue that our generalised planar black holes allow us to construct a model of the internal s…
Hall Viscosity in the Quark-Gluon Plasma
研究非对称重离子碰撞中夸克-胶子等离子体的霍尔粘性，通过扩展动力学理论机制，推导出霍尔粘性与剪切变形的关系，并探讨其在流体动力学初始化中的可观测影响。
The present article is the followup of {\color{blue} Eur.\ Phys.\ J.\ C {\bf 79}, 761 (2019)}, where we have studied the energy-loss of the heavy quarks traversing through the isotropic collisional hot QCD medium. Since, the exploration of QCD phase diagram is possible with the upcoming experimental facilities such as Anti-proton and Ion Research (FAIR) and Nuclotron-based Ion Collider fAcility (NICA), at finite baryon density and moderate temperature, the inclusion of finite chemical potential is essential to study the hot QCD/QGP medium. Therefore, the aim is to develop a formalism to study …
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