In this talk, we present a novel QCD spectral sum rule at finite temperature incorporating contributions from both the (chromo)electric scale $gT$ and the (chromo)magnetic scale $g^2T$. The sum rule uncovers a strongly coupled QCD thermal spectral function containing both massive quasiparticle modes generated by the electric scale and a massless hydro-like mode generated by the magnetic scale....
We will discuss the recent developments on quantum kinetic theory with collisions and its applications to the local spin polarization and spin alignment. We simulate the local spin polarization by the relativistic hydrodynamics combined with the results derived from quantum kinetic theory. We have discussed the interaction corrections to the local spin polarization. Meanwhile, we also...
Non-central heavy-ion collisions produce some of the strongest magnetic fields in the universe and hence provide a unique setting to study QCD matter under extreme conditions. I will introduce BHAC-QGP, a derivation of the (3+1)D GRMHD Black Hole Accretion Code that is designed to investigate the influence of magnetic fields on final state observables and anomalous transport phenomena....
Searching for possible signals from the QCD critical point and the associated first-order phase transition is one of the most important goals of high-energy heavy-ion experiments. Occurrence of the first-order phase transition is likely accompanied by large spatial density fluctuations due to the spinodal instabilities. Trough a transport model approach, we study effects of the first-order...
Based on the Kharzeev-McLerran-Warringa (KMW) model that estimates strong electromagnetic (EM) fields generated in relativistic heavy-ion collisions, we generalize the formulas of EM fields in the vacuum by incorporating the longitudinal position dependence, the generalized charge distributions and retardation correction. We further generalize the formulas of EM fields in the pure quark-gluon...
This presentation is based on an event-by-event study of RHIC which is initialized by McLerran-Venugopalan (MV) model. Topological charge is related to the gauge invariant $F_{\mu\nu}\tilde{F^{\mu\nu}}$, where $F_{\mu\nu}$ and $\tilde{F^{\mu\nu}}$ denote the Yang-Mills field strength tensor and its dual. The chiral density is produced via the chiral anomaly of Quantum Chromodynamics. Firstly,...
We derive form factors for massless fermions, which has an analogous structures as that of chiral kinetic theory. We further use it describe the local spin polarization in relativistic spin hydrodynamics. To achieve this, we use the metric perturbation to mimic the fluid gradient. The coupling spin and fluid gradient arise in two forms: one corresponds to the potential correction modifying the...
The chirality imbalance in QCD is spontaneously induced by a repulsive axial-vector interaction from the instanton anti-instanton pairing at high temperature above the chiral phase transition, and vanishes at low temperature. The chiral chemical potential μ5 is in the same magnitude as estimated from the sphaleron transition. Phase transition of the chirality imbalance is always a first-order...
In this abstract I summarize some of our recent works about heavy quark potential and dynamics in a magnetized medium to discuss the effect of the magnetic field on various observables.
For the first part we present a calculation of the heavy quark momentum diffusion coefficients in a quark-gluon plasma under the presence of a strong external magnetic field, within the lowest Landau level...
Based on a general analysis of conservation laws, the duality between gravity and hydrodynamics of a relativistic quantum fluid in a flat space is shown. This duality is expressed in the equality between hydrodynamic transport coefficients and quantum corrections in curved space-time. It is shown that the gravitational chiral anomaly is dual to the axial current in the vortical and accelerated...
Based on the Nambu-Jona-Lasinio (NJL) model, we develop a framework for calculating the spin alignment of vector mesons and applied it to study $\phi$ mesons in a magnetic field. We calculate mass spectra for $\phi$ mesons and observe mass splitting between the longitudinally polarized state and the transversely polarized state. The $\phi$ meson in a thermal equilibrium system is preferred to...
The chiral kinetic theory (CKT) is a great theoretical framework for the transport phenomena of massless degrees of freedom. In spite of various developments, the nonlinear order quantum correction to the CKT is less understood. In this talk, employing the Wigner function, I develop the off-equilibrium CKT including the nonlinear quantum correction at $O(\hbar^2)$. This nonlinear CKT involves...
We present a new derivation of Israel-Stewart-like relativistic second-order dissipative spin hydrodynamic equations using entropy current analysis [arXiv:2304.01009]. The motivation behind this research stems from the identification of unstable solutions in the linearized first-order spin hydrodynamic evolution equations [10.1103/PhysRevD.107.054043] as well as from the unphysical dynamics...
We propose a method to find local plane wave solutions to linearized equations of motion of relativistic hydrodynamics in inhomogeneous backgrounds, i.e., when fluid is rigidly moving with nonzero thermal vorticity in equilibrium. Our method is based on extending the conserved currents to the tangent bundle, using Wigner transforms. The Wigner-transformed conserved currents can then be Fourier...
We derive an expression for the tensor polarization of a system of massive spin-1 particles in a hydrodynamic framework. Starting from quantum kinetic theory based on the Wigner-function formalism, we employ a modified method of moments which also takes into account all spin degrees of freedom. It is shown that the tensor polarization of an uncharged fluid is determined by the shear-stress...
We study the two-point functions from chiral kinetic theory which characterize the response to perturbative vector and axial gauge fields in magnetized chiral plasma. In the lowest Landau level approximation, the solution of chiral kinetic equations gives density waves of electric and axial charges, which contain chiral magnetic wave implied by the axial anomaly and magnetic field. We then...
Polarization measurements represent an important tool for understanding the particle production mechanisms occurring in proton proton collisions. In particular, for quarkonium states, the very small polarization measured at the LHC represents a serious and a long-lasting challenge for theoretical models. When considering heavy-ion collisions, particle polarization could also be used to...
One of the recent puzzles in hadron physics is how to define energy, momentum, spin and stress density distributions inside a hadron. The standard picture is that a hadron is a femtometer spherical ball, whose radial density profile is dictated by Strong Interaction. Given the so-called gravitational form factors (GFFs) either from the experimental measurements or theory, the energy, momentum...
