Quarkonium hybrids

We discuss the quarkonium hybrid spectrum from the perspective of nonrelativistic effective field theories combined with lattice QCD.Comment: 8 pages, 7 figures, presented at "The European Physical Society Conference on High Energy Physics - EPS-HEP 2017" (5 - 12 July 2017, Venice, Italy

A low-energy determination of αs\alpha_s at three loops

We review one of the most accurate low-energy determinations of $\alpha_s$. Comparing at short distances the QCD static energy at three loops and resummation of the next-to-next-to leading logarithms with its determination in 2+1-flavor lattice QCD, we obtain $\alpha_s(1.5~{\rm GeV})=0.336^{+0.012}_{-0.008}$, which corresponds to $\alpha_s(M_Z)=0.1166^{+0.0012}_{-0.0008}$. We discuss future perspectives.Comment: 9 pages, 8 figures, 4th International Conference on New Frontiers in Physics, Crete, August 2015 and XLV International Symposium on Multiparticle Dynamics, Wildbad Kreuth, October 201

Non-relativistic bound states: the long way back from the Bethe-Salpeter to the Schroedinger equation

I review, in a personal perspective, the history of the theory of non-relativistic bound states in QED and QCD from the Bethe-Salpeter equation to the construction of effective field theories.Comment: Contribution to "Fundamental Interactions - A Memorial Volume for Wolfgang Kummer", D. Grumiller, A. Rebhan, D.V. Vassilevich (eds.); 17 pages, 6 figures; references adde

Heavy quarkonium decays and transitions in the language of effective field theories

Heavy quarkonium decays and transitions are discussed in the framework of non-relativistic effective field theories. Emphasis is put on the matching procedure in the non-perturbative regime. Some exact results valid for the magnetic dipole couplings are discussed.Comment: 7 pages; Talk given at Hadron 05, Rio de Janeiro, August 22-26, 2005 and QCD@Work 2005, Conversano, June 16-20, 200

Open Problems in Heavy Quarkonium Physics

Some recent progress and a personal selection of open problems in heavy quarkonium physics (spectroscopy, decay and production) inspired by the activity of the Quarkonium Working Group are reviewed.Comment: Plenary talk presented at the 6th international conference Quark Confinement and the Hadron Spectrum, Villasimius, Italy 21-25 September, 2004; 11 pages, 7 figures, aippro

The BcB_c mass up to order αs4\alpha_s^4

We evaluate in perturbative QCD, up to order $\alpha_s^4$, the mass of the $B_c$. We use the so-called 1S-mass in order to improve the convergence of the perturbative series. Our result is $E(B_c)_{pert} = 6326^{+29}_{-9}$ MeV. Non-perturbative effects are discussed. A comparison with potential models seems to be consistent with non-perturbative contributions of the order $- (40\div 100)$ MeV.Comment: 14 pages, revtex, 2 figures, minor changes, discussion on the non-perturbative corrections added, final version to appear in Phys. Rev.

Radiative transitions and the quarkonium magnetic moment

I discuss heavy quarkonium radiative transitions and the related issue of the quarkonium magnetic moment inside effective field theories. Differences in set up and conclusions with respect to typical phenomenological approaches are outlined.Comment: 7 pages, to appear in the proceedings of Workshop on Continuous Advances in QCD 2006, Minneapolis, Minnesota, 11-14 May 200