A non-perturbative (np) method of Field Correlators (FCM) was applied to study QCD at temperatures above the deconfinement transition ($1<T/T_c<3,~T_c\sim0.16~GeV$) and nonzero baryon densities (baryon chemical potential $μ_B<0.5~GeV$) in an external uniform magnetic field ($eB<0.5~GeV^2$). Within FCM, the np high-temperature dynamics is embodied in the Polyakov loop and in the Debye mass due to the Color-Magnetic Confinement. Analytic expressions for quark pressure and magnetic susceptibility were obtained. The expressions were represented as series and in integral form. Magnetic susceptibility was found to increase rapidly with temperature and slowly with density. The results at the zero density limit are in agreement with lattice data.
A quasiclassical theory of the synchrotron-like gluon emission is discussed. We show that the synchrotron emission may be important in the jet quenching if the plasma instabilities generate a chromomagnetic field about $m^{2}_{D}/g$. Our gluon spectrum disagrees with that obtained by Shuryak and Zahed within Schwinger's proper time method.
The gluon polarization tensor for the quark-gluon plasma with shear viscosity is derived with the viscous chromohydrodynamics. The longitudinal and transverse dielectric functions are evaluated from the gluon polarization tensor, through which the polarization energy loss suffered by a fast quark traveling through the viscous quark-gluon plasma is investigated. The numerical analysis indicates that shear viscosity significantly reduces the polarization energy loss.
We review both lattice evidences and theoretical arguments supporting the existence of electric flux tubes in quark-gluon plasma, above the deconfinement transition temperature $T>T_c$. At the end of this comment, we also point out certain questions which still needs to be answered.
The transverse and longitudinal transport coefficients for jets in a quark-gluon plasma, $\hat{q}$ and $\hat{e}$, are extracted from simulations of the VNI/BMS parton cascade model. We study their variation under the strong coupling and the parton mass in the medium. We show that their ratio is sensitive to the mass of the plasma constituents. Experimental measurements of both quantities could provide new insights into the nature of the quark-gluon plasma as seen by hard probes.
Some aspects of heavy flavor probes of quark-gluon plasma (QGP) including quarkonia and open heavy flavor D- and B-mesons, aimed to study the properties of QGP, are discussed in this lecture note.
We study radiative parton energy loss in an expanding quark-gluon plasma with magnetic monopoles. We find that for realistic number density of thermal monopoles obtained in lattice simulations parton rescatterings on monopoles can considerably enhance energy loss for plasma produced in $AA$ collisions at RHIC and LHC energies. However, contrary to previous expectations, monopoles do not lead to the surface dominance of energy loss.
We demonstrate that for a finite-size quark-gluon plasma the induced gluon radiation from heavy quarks is stronger than that for light quarks when the gluon formation length becomes comparable with (or exceeds) the size of the plasma. The effect is due to oscillations of the light-cone wave function for the in-medium $q\to gq$ transition. The dead cone model by Dokshitzer and Kharzeev neglecting quantum finite-size effects is not valid in this regime. The finite-size effects also enhance the photon emission from heavy quarks.
A quark propagating through the quark gluon plasma and scattering off the thermal gluons can radiate photons in states with definite angular momentum and magnetic helicity. These states, known as the Chandrasekhar-Kendall states, are eigenstates of the curl operator and have a non-trivial topology. I compute spectrum of these states in the ultrarelativistic limit and study its properties.
The role of color-magnetic monopoles in a pure gauge plasma at high temperature $T>2T_c$ is considered. In this temperature regime, monopoles can be considered heavy, rare objects embedded into matter consisting mostly of the usual "electric" quasiparticles, quarks and gluons. The gluon-monopole scattering is found to hardly influence thermodynamic quantities, yet it produces a large transport cross section, significantly exceeding that for pQCD gluon-gluon scattering up to quite high $T$. This mechanism keeps viscosity small enough for hydrodynamics to work at LHC.
We explore the thermodynamics of the gluon plasma in SU(3) Yang-Mills theory emerging from the non-trivial spatial dynamics of valence gluons. The lattice data suggest that these gluons interact with each other linearly at large spatial separations. At high temperatures, valence gluons should reproduce the pressure of the non-interacting Stefan-Boltzmann plasma along with the leading perturbative correction. These properties of valence gluons can be modeled in terms of the integral over their trajectories. We calculate such a world-line integral analytically and obtain the pressure and the int…
