Related papers: Strong coupling constant from the 1-loop improved …
We extract an effective strong coupling constant using low-Q^2 data and sum rules. Its behavior is established over the full Q^2-range and is compared to calculations based on lattice QCD, Schwinger-Dyson equations and a quark model.…
We determine the 2-loop effective gauge coupling of QCD at high temperatures, defined as a matching coefficient appearing in the dimensionally reduced effective field theory. The result allows to improve on one of the classic…
The successive perturbative estimates of the pressure of QCD at high temperature T show no sign of convergence, unless the coupling constant g is unrealistically small. Exploiting known results of an effective field theory which separates…
Hamiltonian lattice QCD with Wilson fermions is investigated systematically by strong-coupling expansion up to the second order. The effective Hamiltonian is diagonalized by Bogoliubov transformation. The vacuum energy, chiral condensate,…
We present results for the reference scale r_0 in SU(3) Lattice Gauge Theory for beta = 6/g_0^2 in the range 5.7 <= beta <= 6.57. The high relative accuracy of 0.3-0.6% in r_0/a was achieved through good statistics, the application of a…
The status of determinations of $\al_s$ from quarkonia using lattice QCD is reviewed. We compare the results with those obtained from perturbative QCD.
Effective Polyakov loop theories are a useful tool for an investigation of pure Yang-Mills theory and full QCD. A systematic derivation of the effective action can be done in a spatial strong coupling expansion. Quite accurate predictions…
We present a determination of the strong coupling constant $\alpha_s(m_Z)$ using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS…
In this note we summarize the results from a longer article on obtaining the QCD phase diagram as a function of the temperature and chemical potential at large Nc and large Nf in the weak and the strong coupling limits. The weak coupling…
Pure gauge theories can be formulated in terms of Wilson Loops correlators by means of the loop equation. In the large-N limit this equation closes in the expectation value of single loops. In particular, using the lattice as a regulator,…
We use the recently obtained theoretical expression for the complete QCD static energy at next-to-next-to-next-to leading-logarithmic accuracy to determine r_0Lambda_MS by comparison with available lattice data, where r_0 is the lattice…
From the analysis of the perturbative expansion of the lattice regularized gluon condensate, toghether with MC data, we present evidence of OPE-unexpected dim-2 power corrections in the scaling behaviour of the Wilson loop. These can be…
We test a method for computing the static quark-antiquark potential in lattice QCD, which is not based on Wilson loops, but where the trial states are formed by eigenvector components of the covariant lattice Laplace operator. The runtime…
A model for SU(n) string breaking on the lattice is formulated using strong coupling ideas. Although necessarily rather crude, the model gives an explicit picture of string breaking in the presence of dynamical quarks as a mixing phenomenon…
We review lattice determinations of the charm and bottom quark masses and the strong coupling constant obtained by different methods. We explain how effective field theory approaches, such as Non-Relativistic QCD (NRQCD), potential…
We compute the hadronic running of the electromagnetic and weak couplings in lattice QCD with $N_{\mathrm{f}}=2+1$ flavors of $\mathcal{O}(a)$ improved Wilson fermions. Using two different discretizations of the vector current, we compute…
We consider a 2+1-dimensional SU(N) lattice gauge theory in an axial gauge with the link field U in the 1-direction set to one. The term in the Hamiltonian containing the square of the electric field in the 1-direction is non-local. Despite…
We present a new dispersive framework for the extraction of the strong coupling constant $\alpha_s$ from $\tau$-lepton decays. A new feature of our procedure is the use of the quark-hadron duality on the limited region $s_{\rm…
We calculate the 3-loop perturbative expansion of the average plaquette in lattice QCD with N_f massive Wilson fermions and gauge group SU(N). The corrections to asymptotic scaling in the corresponding energy scheme are also evaluated. We…
The weak-coupling expansion for thermodynamic quantities in thermal field theories is poorly convergent unless the coupling constant is tiny. We discuss the calculation of the free energy for a hot gas of electrons and photons to three-loop…