New Charmonium States in QCD Sum Rules: a Concise Review

TL;DR

This review discusses recent experimental discoveries of new charmonium-like states and evaluates their interpretation using QCD sum rules, highlighting the progress and challenges in hadron spectroscopy.

Contribution

It provides a comprehensive overview of recent experimental data on charmonium states analyzed through QCD sum rules, comparing results with other theoretical approaches.

Findings

Identification of new charmonium-like states

Comparison of QCD sum rule results with experimental data

Discussion of theoretical interpretations and challenges

Abstract

In the past years there has been a revival of hadron spectroscopy. Many interesting new hadron states were discovered experimentally, some of which do not fit easily into the quark model. This situation motivated a vigorous theoretical activity. This is a rapidly evolving field with enormous amount of new experimental information. In the present report we include and discuss data which were released very recently. The present review is the first one written from the perspective of QCD sum rules (QCDSR), where we present the main steps of concrete calculations and compare the results with other approaches and with experimental data.