New results on inclusive quarkonium decays

I review some recent progress, leading to a substantial reduction in the number of non-perturbative parameters, in the calculation of inclusive quarkonium decay widths in the framework of non-relativistic effective field theories.Comment: 4 pages, 3 figures, to be published in the proceedings of the XXXVIIth Rencontres de Moriond (QCD and High Energy Hadronic Interactions), 16-23 March 2002, Les Arcs, Franc

Is there a linear potential at short distances?

We argue that the lattice data of the static potential can be explained by perturbation theory up to energies of the order of 1 GeV once renormalons effects are taken into accountComment: 6 pages, 5 figures, Invited talk given at QCD03, 2-9 July, Montpellier, Franc

The static potential: lattice versus perturbation theory in a renormalon-based approach

We compare, for the static potential and at short distances, perturbation theory with the results of lattice simulations. We show that a renormalon-dominance picture explains why in the literature sometimes agreement, and another disagreement, is found between lattice simulations and perturbation theory depending on the different implementations of the latter. We also show that, within a renormalon-based scheme, perturbation theory agrees with lattice simulations.Comment: 18 pages, 11 figures, lattice data of Necco and Sommer introduced, references added, some lengthier explanations given, physical results unchange

Hybrid potentials versus gluelumps

A potential model description of heavy quarkonium can be rigorously deduced from QCD under some circumstances. The potentials can be unambiguously related with Wilson loops with gluonic insertions, the spectral decomposition of which is a function of the spectrum and matrix elements solution of the static limit of NRQCD. This spectrum is nothing but the static singlet potential and the hybrid potentials (which correspond to the gluonic excitations). We will quantitatively show that the latter unambiguously relate to the gluelumps at short distances using effective field theories.Comment: 7 pages, 2 figures, Invited Plenary talk at the Conference ``Quark Confinement and the Hadron SpectrumVII''. 2-7th Sept. 2006. Ponta Delgada, Azores Islands. Portuga

Large order behavior in perturbation theory of the pole mass and the singlet static potential

We discuss upon recent progress in our knowledge of the large order behavior in perturbation theory of the pole mass and the singlet static potential. We also discuss about the renormalon subtracted scheme, a matching scheme between QCD and any effective field theory with heavy quarks where, besides the usual perturbative matching, the first renormalon in the Borel plane of the pole mass is subtracted.Comment: 6 pages, LaTeX, AIP proceedings style. Talk given at QCD@work conference, Martina Franca, Italy, 16-20 Jun 2001. One reference adde