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

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

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

Transverse momentum broadening and gauge invariance

In the framework of the soft-collinear effective theory, we present a gauge invariant definition of the transverse momentum broadening probability of a highly-energetic collinear quark in a medium and consequently of the jet quenching parameter $\hat{q}$.Comment: 8 pages, 7 figures; contribution to QCD@Work 2012, Lecce, June 18-21, 201

Quarkonium in a weakly-coupled quark-gluon plasma

We report about a recent calculation of the heavy quarkonium mass and decay width in a quark-gluon plasma, whose temperature T and screening mass m_D satisfy the hierarchy m alpha_s >> pi T >> m alpha_s^2 >> m_D, m being the heavy-quark mass, up to order m alpha_s^5. The calculation may be relevant to understand the behavior of the Y(1S) in a quark-gluon plasma at present-day colliders.Comment: 9 pages, 2 figures; contribution to QCD@Work 2010, Martina Franca, June 20-23, 201

Quarkonium dissociation in a thermal bath

In an effective field theory framework we review the two main mechanisms of quarkonium dissociation in a weakly coupled thermal bath.Comment: Plenary talk given at the 11th Conference Quark Confinement and the Hadron Spectrum, September 8-12, 2014, Saint-Petersburg, Russia; 9 pages, 10 figure