Related papers: The Three Loop Two-Mass Contribution to the Gluon …
The anomalous magnetic moment of the muon is one of the most fundamental observables. It has been measured experimentally with a very high precision and on theory side the contributions from perturbative QED have been calculated up to…
We study a model of quark-gluon plasma of 2+1 flavors Quantum Chromodynamics in terms of quasiparticles propagating in a condensate of Polyakov loops. The Polyakov loop is coupled to quasiparticles by means of a gas-like effective…
Loop quantum gravity is a physical theory which aims at unifying general relativity and quantum mechanics. It takes general relativity very seriously and modifies it via a quantisation. General relativity describes gravity in terms of…
We consider a process of quasielastic $e\mu$ large-angle scattering at high energies with radiative corrections up to a two-loop level. A lowest order radiative correction arising both from one-loop virtual photon emission and a real soft…
Hadronic vacuum polarization at low virtualities limits the precision of experimental tests of the standard model via important physical observables. Here we compute that effect in two-flavor chiral perturbation theory to three loops. Among…
In the context of the so-called valon model, we calculate $\frac{\delta g}{g}$ and show that although it is small and compatible with the measured values, the gluon contribution to the spin of nucleon can be sizable. The smallness of…
We propose a new reformulation of Yang-Mills theory in which three- and four-gluon self-interactions are eliminated at the price of introducing a sufficient number of auxiliary fields. We discuss the validity of this reformulation in the…
We study the photon-quark-quark and Higgs-gluon-gluon form factors for on-shell massless quarks and gluons in perturbative QCD. Previous third-order results for the quark case are extended by calculating the fermion-loop contributions up to…
We present calculations of the one-loop vacuum polarization correction (Uehling potential) for the three-body problem in the NRQED formalism. The case of one-electron molecular systems is considered. Numerical results of the vacuum…
An expression for the photon condensate in quantum electrodynamics is presented and generalized to deduce a simple relation between the gluon condensate and the running coupling constant of quantum chromodynamics (QCD). Ambiguities in…
The hadronic vacuum polarization contribution to the anomalous magnetic moment of a lepton is considered as a function of the lepton mass. We show how the analyticity properties of this function allow for its full reconstruction when it is…
It had been known that the Borel transforms of the twice quark pole mass 2*mq and of the QCD q-barq static potential V(r) have leading infrared renormalons at b=1/2 such that they cancel in the sum. The renormalon residue of 2*mq had been…
The rotation of the polarization vector for light propagating perpendicular to an external constant external magnetic field $B$, is calculated in quantum vacuum, where it leads to different photon eigenmodes of the magnetized photon…
The contribution of the $\alpha^3$ single electron-loop vacuum-polarization diagrams to the Lamb shift of the muonic hydrogen has been evaluated recently by two independent methods. One uses the exact parametric representation of the…
In this note the leptonic contribution to the running of the electromagnetic coupling constant is discussed up to the three-loop level. Special emphasize is put on the evaluation of the double-bubble diagrams.
We calculate the thermodynamic functions of Yang-Mills theory to three-loop order using the hard-thermal-loop perturbation theory reorganization of finite temperature quantum field theory. We show that at three-loop order hard-thermal-loop…
In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions…
We compute the vacuum polarisation on the lattice in quenched QCD using non-perturbatively improved Wilson fermions. Above Q^2 of about 2 GeV^2 the results are very close to the predictions of perturbative QCD. Below this scale we see signs…
We calculate the thermodynamic functions of a quark-gluon plasma for general N_c and N_f to three-loop order using hard-thermal-loop perturbation theory. At this order, all the ultraviolet divergences can be absorbed into renormalizations…
I calculate the 1-loop vacuum polarization $\Pi_{\mu\nu}(k,B,a)$ for a photon of momentum $k=(\hat k,k_3)$ interacting with the electrons of a thin medium of thickness $2a$ simulating graphene, in the presence of a constant and uniform…