Related papers: Gluon masses without seagull divergences
The observational consequences of certain broken symmetries in a thermalised quark gluon plasma are elucidated. The signature under study is the spectrum of dileptons radiating from the plasma, through gluon fusion. Being a pure medium…
We discuss gluon production by the Schwinger mechanism in collinear color-electric and magnetic fields which may be realized in pre-equilibrium stages of ultra-relativistic heavy-ion collisions. Fluctuations of non-Abelian gauge fields…
A complication in proving factorization theorems in Feynman gauge is that individual graphs give a super-leading power of the hard scale when all the gluons inducing the hard scattering are longitudinally polarized. With the aid of an…
A constraint correlation dynamics up to 4-point Green functions is proposed for SU(N) gauge theories which reduces the N-body quantum field problem to the two-body level. The resulting set of nonlinear coupled equations fulfills all…
Medium-induced gluon radiation is usually identified as the dominant dynamical mechanism underling the {\it jet quenching} phenomenon observed in heavy-ion collisions. In its actual implementation, multiple medium-induced gluon emissions…
We review recent developments in the study of gluon scattering amplitudes of the four-dimensional maximally supersymmetric Yang-Mills theory at strong coupling based on the gauge/string duality and its underlying integrability. The…
In a functional approach to QCD the infrared behaviour of Landau gauge Green functions is investigated. Positivity violation for, and thus confinement of, gluons is demonstrated, and the analytic structure of the gluon propagator is…
We investigate Landau gauge $SU(3)$ Yang-Mills theory in a systematic vertex expansion scheme for the effective action with the functional renormalisation group. Particular focus is put on the dynamical creation of the gluon mass gap at…
The gluon spin coupling to a Gaussian correlated background gauge field induces an effective tachyonic gluon mass. It is momentum dependent and vanishes in the UV only like 1/p^2. In the IR, we obtain stabilization through a positive…
Based on hep-ph/0510121, we discuss further the numerical study of classical SU(2) 3+1-D Yang-Mills equations for matter produced in a high energy heavy ion collision. The growth of the amplitude of fluctuations as $\exp{(\Gamma…
In the framework of the functional renormalization group, we reexamine the stability of the Yang-Mills vacuum with a chromomagnetic condensation. We show that the Nielsen-Olesen instability of the Savvidy vacuum with a homogeneous…
We present a comprehensive numerical study of dynamical mass generation for unquenched QED in four dimensions, in the absence of four-fermion interactions, using the Dyson--Schwinger approach. We begin with an overview of previous…
Based on a suitable basis system for the quark-gluon vertex' transverse tensor structures and on carefully chosen kinematical variables, the transverse part of the quark-gluon vertex in quenched QCD in the Landau gauge is obtained from a…
Recently, a theoretical framework was set up in [1], which allows for the symmetry-preserving inclusion of full quark-gluon vertices in the description of the meson dynamics. In the present work, we develop a special truncation within this…
The non-equilibrium quantum field dynamics is usually described in the closed-time-path formalism. The initial state correlations are introduced into the generating functional by non-local source terms. We propose a functional approach to…
Within the Euclidean path integral and mass perturbation theory we derive, from the Dyson-Schwinger equations of the massive Schwinger model, a general formula that incorporates, for sufficiently small fermion mass, all the bound-state mass…
The possible infrared behaviour of the gluon propagator is studied analytically, using the Schwinger-Dyson equations, in both the axial and the Landau gauge. The possibility of a gluon propagator less singular than $1/k^{2}$ when $k^{2}…
It is proposed to consider the fast thermalization of gluons in relativistic heavy-ion collisions as a diffusion process in momentum space. Closed-form analytical solutions of a nonlinear boson diffusion equation (NBDE) with constant drift…
Truncated Dyson-Schwinger equations represent finite subsets of the equations of motion for Green's functions. Solutions to these non-linear integral equations can account for non-perturbative correlations. We describe the solution to the…
The Schwinger-Dyson quark equation (SDE) combined with results from lattice simulation for the propagators are used to obtain information on the quark-gluon vertex, taking into account the recent full QCD lattice results for the soft-gluon…