arXiv subjects

Lihua Dong

Publications and source records attributed to Lihua Dong.

11 recordsLinked to original sources

arXiv2025

Influence of a nontrivial Polyakov loop on the quarkonium states

Using a hybrid approach based on a phenomenological heavy-quark potential model and the background field effective theory, we assess the influence of a nontrivial Polyakov loop on the in-medium properties of the heavy quarkonium states. Without resorting to any temperature-dependent parameter, the lattice simulations on the complex heavy-quark potential are well reproduced with the potential model in which the screening masses are determined by the background field effective theory. Due to the reduced screening strength near the deconfining temperature, a nontrivial Polyakov loop leads to a dramatic increase in the binding energies, together with a moderate decrease in the decay widths. In general, a more tightly bounded quarkonium state can be expected, although the increase in the dissociation temperatures is significant only for relatively large-size bounded states. Our results indicate that the background field modification on the binding and decay of the quarkonium states may have a notable impact on the density evolution of quarkonia during the expansion of the fireball, and thus on the final observed quarkonium spectra.

hep-ph↗

arXiv2024

Polarization Dynamics in Paramagnet of Charged Quark-Gluon Plasma

It is commonly understood that the strong magnetic field produced in heavy ion collisions is short-lived. The electric conductivity of the quark-gluon plasma is unable to significantly extend the life time of magnetic field. We propose an alternative scenario to achieve this: with finite baryon density and spin polarization by the initial magnetic field, the quark-gluon plasma behaves as a paramagnet, which may continue to polarize quark after fading of initial magnetic field. We confirm this picture by calculations in both quantum electrodynamics and quantum chromodynamics. In the former case, we find a splitting in the damping rates of probe fermion with opposite spin component along the magnetic field. In the latter case, we find a similar splitting in damping rate of probe quark in quark-gluon plasma in both high density and low density limits. The splitting provides a way of polarizing strange quarks by the quark-gluon plasma paramagnet consisting of light quarks, which effectively extends the lifetime of magnetic field in heavy ion collisions.

hep-ph↗

arXiv2023

Direct Laser Writing of Surface Micro-Domes by Plasmonic Bubbles

Plasmonic microbubbles produced by laser irradiated gold nanoparticles (GNPs) in various liquids have emerged in numerous innovative applications. The nucleation of these bubbles inherently involves rich phenomena. In this paper, we systematically investigate the physicochemical hydrodynamics of plasmonic bubbles upon irradiation of a continuous wave (CW) laser on a GNP decorated sample surface in ferric nitrate solution. Surprisingly, we observe the direct formation of well-defined micro-domes on the sample surface. It reveals that the nucleation of a plasmonic bubble is associated with the solvothermal decomposition of ferric nitrate in the solution. The plasmonic bubble acts as a template for the deposition of iron oxide nanoparticles. It first forms a rim, then a micro-shell, which eventually becomes a solid micro-dome. Experimental results show that the micro-dome radius Rd exhibits an obvious dependence on time t, which can be well interpreted theoretically. Our findings reveal the rich phenomena associated with plasmonic bubble nucleation in a thermally decomposable solution, paving a plasmonic bubble-based approach to fabricate three dimensional microstructures by using an ordinary CW laser.

physics.plasm-ph↗

arXiv2023

Sub-megahertz nucleation of plasmonic vapor microbubbles by asymmetric collapse

Laser triggered and photothermally induced vapor bubbles have emerged as promising approaches to facilitate optomechanical energy conversion for numerous relevant applications in micro/nanofluidics. Here we report the observation of a sub-megahertz spontaneous nucleation of explosive plasmonic bubbles, triggered by a continuous wave laser. The periodic nucleation is found to be a result of the competition of Kelvin impulsive forces and thermal Marangoni forces applied on residual bubbles after collapse. The former originates from asymmetric bubble collapse, resulting in the directed locomotion of residual bubbles away from the laser spot. The latter arises in a laser irradiation induced heat affected zone (HAZ). When the Kelvin impulses dominates, residual bubbles move out of the HAZ and the periodic bubble nucleation occurs, with terminated subsequent steadily growing phases. We experimentally and numerically study the dependence of the nucleation frequency f on laser power and laser spot size. Moreover, we show that strong fluid flows over 10 mm/s in a millimeter range is steadily achievable by the periodically nucleated bubbles. Overall, our observation highlights the opportunities of remotely realizing strong localized flows, paving a way to achieve efficient micro/nanofluidic operations.

physics.flu-dyn↗

arXiv2023

On asymptotic stability of the 3D Boussinesq equations without thermal conduction

We investigate the asymptotic stability of solution to Boussinesq equations without thermal conduction with the initial data near a specific stationary solution in the three--dimensional domain $Ω= \mathbb{R}^{2}\times (0,1)$. It is shown that the solution starting from a small perturbation to the stationary solution converges to it with explicit algebraic rates as time tends to infinity.

math.AP↗

arXiv2022

The effective complex heavy-quark potential in an anisotropic quark-gluon plasma

We introduce a method for reducing anisotropic heavy-quark potentials to isotropic potentials by using an effective screening mass that depends on the quantum numbers $l$ and $m$ of a given state. We demonstrate that, using the resulting 1D effective potential model, one can solve a 1D Schrödinger equation and reproduce the full 3D results for the energies and binding energies of low-lying heavy-quarkonium bound states to relatively high accuracy. This includes the splitting of different p-wave polarizations. The resulting 1D effective model provides a way to include momentum anisotropy effects in open quantum system simulations of heavy-quarkonium dynamics in the quark-gluon plasma.

hep-ph↗

arXiv2022

Dilepton Helical Production in a Vortical Quark-Gluon Plasma

In this paper, we propose an observable counting a weighted difference between right-handed and left-handed lepton pairs, which is coined dilepton helical rate. The weight is the momentum difference of the lepton pairs projected onto an auxiliary vector. We derive the helical rate in a quark-gluon plasma with a vorticity in the limit when the quark and lepton masses are ignored. We find the helical rate is maximized when the auxiliary vector is parallel to the vorticity, in which case it has a nearly spherical oblate ellipsoidal distribution. We propose that it can be used as a vortical-meter for quark-gluon plasma.

hep-ph↗

arXiv2022

The complex heavy-quark potential in an anisotropic quark-gluon plasma -- Statics and dynamics

We generalize a complex heavy-quark potential model from an isotropic QCD plasma to an anisotropic one by replacing the Debye mass $m_D$ with an anisotropic screening mass depending on the quark pair alignment with respect to the direction of anisotropy. Such an angle-dependent mass is determined by matching the perturbative contributions in the potential model to the exact result obtained in the Hard-Thermal-Loop resummed perturbation theory. An advantage of the resulting potential model is that its angular dependence can be effectively described by using a set of angle-averaged screening masses as proposed in our previous work. Consequently, one could solve a one-dimensional Schrödinger equation with a potential model built by changing the anisotropic screening masses into the corresponding angle-averaged ones, and reproduce the full three-dimensional results for the binding energies and decay widths of low-lying quarkonium bound states to very high accuracy. Finally, turning to dynamics, we demonstrate that the one-dimensional effective potential can accurately describe the time evolution of the vacuum overlaps obtained using the full three-dimensional anisotropic potential. This includes the splitting of different p-wave polarizations.

hep-ph↗

arXiv2021

Effective Debye Screening Mass in an Anisotropic Quark Gluon Plasma

Due to the rapid longitudinal expansion of the quark-gluon plasma created in heavy-ion collisions, large local-rest-frame momentum-space anisotropies are generated during the system's evolution. These momentum-space anisotropies complicate the modeling of heavy-quarkonium dynamics in the quark-gluon plasma due to the fact that the resulting inter-quark potentials are spatially anisotropic, requiring real-time solution of the 3D Schrödinger equation. Herein, we introduce a method for reducing anisotropic heavy-quark potentials to isotropic ones by introducing an effective screening mass that depends on the quantum numbers $l$ and $m$ of a given state. We demonstrate that, using the resulting effective Debye screening masses, one can solve a 1D Schrödinger equation and reproduce the full 3D results for the energies and binding energies of low-lying heavy-quarkonium bound states to relatively high accuracy. The resulting effective isotropic potential models could provide an efficient method for including momentum-anisotropy effects in open quantum system simulations of heavy-quarkonium dynamics in the quark-gluon plasma.

hep-ph↗

arXiv2021

Asymptotic stability of the 2D Boussinesq equations without thermal conduction

This paper is concerned with the asymptotic stability of certain stationary solution to Boussinesq equations without thermal conduction in the infinite flat strip $Ω=\mathbb{R}\times (0,1)$. It is shown that the solution starting from initial data close to the stationary solution will converge to it with explicit algebraic rates as time tends to infinity.

math.AP↗

arXiv2019

Modeling the nonperturbative contributions to the complex heavy-quark potential

In this paper, we construct a simple model for the complex heavy quark potential which is defined through the Fourier transform of the static gluon propagator. Besides the hard thermal loop resummed contribution, the gluon propagator also includes a non-perturbative term induced by the dimension two gluon condensate. Within the framework of thermal field theory, the real and imaginary parts of the heavy quark potential are determined in a consistent way without resorting to any extra assumption as long as the exact form of the retarded/advanced gluon propagator is specified. The resulting potential model has the desired asymptotic behaviors and reproduces the data from lattice simulation reasonably well. By presenting a direct comparison with other complex potential models on the market, we find the one proposed in this work shows a significant improvement on the description of the lattice results, especially for the imaginary part of the potential, in a temperature region relevant to quarkonium studies.

hep-ph↗