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Li Jiarong

Publications and source records attributed to Li Jiarong.

13 recordsLinked to original sources
arXiv2003

The Critical Rotation of Strange Stars and Rapidly Rotating Pulsars

We utilize the bulk viscosity of interacting strange quark matter to reevaluate the damping time scale. The presence of medium effect of bulk viscosity leads to a stronger damping of r-modes, which can be over an order of magnitude for realistic parameters. We find that the r-mode instability window is narrowed due to the medium effect, and hence when a pulsar reaches the instability window it will only slow down by gravitational wave emission to a period of 1.78msec instead of 2.5msec given by early estimate. As a theoretical upper rotation limit of pulsars, the period of 1.78msec is very close to the two most rapidly spinning pulsars known, with periods of about 1.6msec.

astro-ph↗
arXiv2002

Bulk viscosity of interacting strange quark matter

The quarks are regarded as quasiparticles, which acquire an effective mass generated by the interaction with the other quarks of the dense system. The bulk viscosity is re-expressed in the case of interacting strange quark matter. We find that the viscosity is a few ~ tens times larger than that of non-interacting quark gas due to the small correction of medium effect to the equation of state. The limiting spins of strange stars will rise so significantly that the pulsars with shorter period may exist.

hep-ph↗
arXiv2002

Kinetic-theory approach to Gluon Self-energy beyond Hard Thermal Loops

We compare the effective dynamics of soft fields, based on temperature field theory, with the mean field dynamics from non-Abelian kinetic theory. We derive the polarization tensor with the leading logarithmic factor $\log({gT\overμ})$ from the effective Boltzmann-Langevin equation given by Litim and Manuel. The tensor is identical with effective one-loop contributions within the hard thermal loop effective theory.

hep-ph↗
arXiv2001

The multiple solutions of self-consistency condition in Walecka model and the validity of the Brown-Rho scaling law

We investigate the self-consistency condition (SCC) of mean-field theory in Walecka model and find that the solutions of the SCC are multiple at high temperature and chemical potential. Using the effective Lagrangian approach, we study medium effects on the $ω$ meson mass by taking into account of vacuum effects. We show that the $ω$ meson mass decreases with both temperature and chemical potential with a general tendency, while near the critical point several $ω$ meson masses become degenerate due to the multiple solutions of the SCC. We check the validity of Brown-Rho scaling law in this case. Finally, we calculate the thermodynamic potential and prove that the multiple solutions of the SCC result from a first-order phase transition of nuclear matter in the Walecka model at high temperature and chemical potential.

hep-ph↗
arXiv2000

The Nonlinear Permittivity Including Non-Abelian Self-interaction of Plasmons in Quark-Gluon Plasma

By decomposing the distribution functions and color field to regular and fluctuation parts, the solution of the semi-classical kinetic equations of quark-gluon plasma is analyzed. Through expanding the kinetic equations of the fluctuation parts to third order, the nonlinear permittivity including the self-interaction of gauge field is obtained and a rough numerical estimate is given out for the important $\vk =0$ modes of the pure gluon plasma.

hep-ph↗
arXiv1999

An effective relaxation-time approach to collisionless quark-gluon plasma

We present an effective relaxation-time theory to study the collisionless quark-gluon plasma. Applying this method we calculate the damping rate to be of order $g^2T$ and find plasmon scattering is the damping mechanism. The damping for the transverse mode is stronger than the longitudinal one.

hep-ph↗
arXiv1999

Non-Abelian Collective Excitations in Unlinearized Quark-Gluon Plasma Media

We study the effect of unlinearized medium on the collective excitations in quark-gluon plasma. We present two kinds of non-Abelian oscillation solutions which respectively correspond to weakly and strongly nonlinear coupling of field components in color space. We also show that the weakly nonlinear solution is similar to Abelian-like one but has the frequency shift, which is of order $g^2T$, from eigenfrequency.

hep-ph↗
arXiv1998

Self-consistent Study on Color Transport in the Quark Gluon Plasma at Finite Chemical Potential

We calculate the relaxation time self-consistently to study the damping of collective color modes and the color conductivity in a QGP by deriving self-consistent equations for the damping rates of gluons and quarks to leading order QCD by TFD including a chemical potential for quarks. We show that the damping rates are not sensitive to the chemical potential whereas color conductivity is enhanced considerably.

hep-ph↗
arXiv1997

Effects of gluon damping rate on the viscosity coefficient of the quark-gluon plasma at finite chemical potential

By considering the Debye screening and damping rate of gluons, the viscosity coefficient of the quark-gluon plasma was evaluated via real-time finite temperature QCD in the relaxation time approximation at finite temperature and chemical potential . The results show that both the damping rate and the chemical potential cause considerable enhancements to the viscosity coefficient of hot dense quark-gluon plasma.

nucl-th↗
arXiv1997

A Colored Particle Acceleration by Fluctuations in QGP

We discuss the energy variation of a parton passing through a quark-gluon plasma(QGP) taking into account nonlinear polarization effect. We find the parton can be accelerated by fluctuations in QGP, which gives us a new physical insight about the response of QGP to such external the current.

hep-ph↗
arXiv1997

The Asymptotic Method Developed from Weak Turbulent Theory and the Nonlinear Permeability and Damping Rate in QGP

With asymptotic method developed from weak turbulent theory, the kinetic equations for QGP are expanded in fluctuation field potential $A^T_μ$. Considering the second-order and third-order currents, we derive the nonlinear permeability tensor function from Yang-Mills field equation, and find that the third-order current is more important in turbulent theory. The nonlinear permeability formulae for longitudinal color oscillations show that the non-Abelian effects are more important than the Abelian-like effects. To compare with other works, we give the numerical result of the damping rate for the modes with zero wave vector.

hep-th↗
arXiv1996

Non-Abelian Kubo Formula and the Multiple Time-Scale Method

The non-Abelian Kubo formula is derived from the kinetic theory. That expression is compared with the one obtained using the eikonal for a Chern-Simons theory. The multiple time-scale method is used to solve the non-Abelian Kubo formula, and the damping rate for longitudinal color waves is computed.

hep-th↗