Review of Heavy Quarkonium at weak coupling

TL;DR

This paper reviews the application of effective field theories, especially potential Non-Relativistic QCD, to understand the properties and dynamics of heavy quarkonium systems at weak coupling, emphasizing computational techniques and various phenomenological applications.

Contribution

It provides a comprehensive overview of how potential Non-Relativistic QCD connects QCD to heavy quarkonium physics using quantum field theory methods, with illustrative examples and applications.

Findings

Effective field theory approach clarifies heavy quarkonium dynamics.

Renormalization group equations are derived and utilized.

Applications include spectroscopy, decays, and production processes.

Abstract

We review weakly-bound heavy quarkonium systems using effective field theories of QCD. We concentrate on potential Non-Relativistic QCD, which provides with a well founded connection between QCD and descriptions of the heavy quarkonium dynamics in terms of Schr\"odinger-like equations. This connection is obtained using standard quantum field theory techniques such as dimensional regularization, which is used throughout, and renormalization. Renormalization group equations naturally follow. Certain effort is made to illustrate how computations are performed and the necessary techniques, providing some examples. Finally, we briefly review a selected set of applications, which include spectroscopy, radiative transitions, Non-Relativistic sum rules, inclusive decays, and electromagnetic threshold production.