相关论文: High temperature QCD and QED with unstable excitat…
After presenting a brief summary of functional approaches to QCD at vanishing temperatures and densities the application of QCD Green's functions at non-vanishing temperature and vanishing density is discussed. It is pointed out in which…
We discuss the infrared and ultraviolet behavior of the fermion propagator in (2+1)-dimensional QED based on spectral representation.If we choose soft-photon exponentiation to include all orders of soft-photon emission by electron,its…
We perform an exact computation of the grand partition function of a model of confined quarks at arbitrary temperatures and quark chemical potentials. The model is inspired by a version of QCD where the perturbative BRST symmetry is broken…
We investigate the in-medium modifications of heavy quarkonia in the vector channel and the heavy quark diffusion coefficient by comparing Euclidean correlators from the lattice to a perturbative spectral function. On the lattice side, we…
We present results of numerical solutions of Schwinger-Dyson equations for the finite-temperature quark and electron propagators. It is shown that both strongly coupled QED and QCD undergo a chiral symmetry restoring phase transition as the…
The dynamics of {\it light} fermions propagating in a spatial direction at high temperatures can be described effectively by a two--dimensional Schr\"odinger equation with {\it heavy} effective mass $m_{\rm eff} = \pi T$. Starting from QED,…
A hallmark of integrable systems is the purely elastic scattering of their excitations. Such systems possess an extensive number of locally conserved charges, leading to the conservation of the number of scattered excitations, as well as…
We investigate gluon spectral functions at finite temperature in Landau gauge, based on a subset of lattice QCD ensembles with $N_f=2+1+1$ dynamical twisted mass quarks flavors, generated by the tmfT collaboration. Our study uses a novel…
In e+e- collisions the particle spectra at low momenta reflect the properties of the underlying "soft" QCD gluon bremsstrahlung: the particle density, in the limit p\to 0, becomes independent of the incoming energy \sqrt{s} and directly…
The grand partition function of a model of confined quarks is exactly calculated at arbitrary temperatures and quark chemical potentials. The model is inspired by a softly BRST-broken version of QCD and possesses a quark mass function…
We present a general method for the high-temperature expansion of the self-energy of interacting particles. Though the method is valid for fermions and bosons, we illustrate it for spin one half fermions interacting via a zero range…
By making use of the finite-temperature real-time static potential that was introduced and computed to leading non-trivial order in Hard Thermal Loop resummed perturbation theory in recent work, and solving numerically a Schr\"odinger-type…
We perform a quark model calculation of the quarkonia $b\overline{b}$ and $c\overline{c}$ spectra using smooth and sudden string breaking potentials. The screening parameter is scale dependent and can be related to an effective running…
Spectral properties of quarks above the critical temperature for deconfinement are analyzed in quenched lattice QCD on lattices of size 128^3x16. We study quark spectral function in energy and momentum space, focusing on the values of the…
We formulate a dressed perturbative expansion of QCD, where the standard diagrams are evaluated in the presence of a constant external gluon field whose magnitude is gaussian distributed. The approach is Poincar{\'e} and gauge invariant,…
The invariant mass spectra of dileptons radiated from the fireballs formed in high-energy heavy-ion collisions have been successfully used to investigate the properties of hot and dense QCD matter. Using a realistic model for the in-medium…
We elaborate on the fact that quarkonium in hot QCD should not be thought of as a stationary bound state in a temperature-dependent real potential, but as a short-lived transient, with an exponentially decaying wave function. The reason is…
Photon and electron spectra in hot and dense QED are found in the high temperature limit for all $|\q|$ using the Feynman gauge and the one-loop self-energy. All spectra are split by the medium and their branches develop the gap (the…
The spectrum of collective fermionic excitations in a finite temperature QED_{3+1} is studied in different regimes. It is shown that within the standard perturbation approach the one-loop dispersion equation, besides the ordinary…
We have observed momentum- and position-resolved spectra and images of the photoluminescence from thermalised and condensed dye-microcavity photons. The spectra yield the dispersion relation and the potential energy landscape for the…