Heavy Quarkonium Physics

This report is the result of the collaboration and research effort of the
\nQuarkonium Working Group over the last three years. It provides a comprehensive
\noverview of the state of the art in heavy-quarkonium theory and experiment,
\ncovering quarkonium spectroscopy, decay, and production, the determination of
\nQCD parameters from quarkonium observables, quarkonia in media, and the effects
\non quarkonia of physics beyond the Standard Model. An introduction to common
\ntheoretical and experimental tools is included. Future opportunities for
\nresearch in quarkonium physics are also discussed.