Quarkonium at the Frontiers of High Energy Physics: A Snowmass White Paper

TL;DR

This paper reviews recent advances and future prospects in quarkonium physics, focusing on spectroscopy of exotic states and high transverse momentum production, highlighting challenges to QCD understanding and experimental opportunities.

Contribution

It presents a comprehensive overview of recent discoveries in quarkonium spectroscopy and discusses new experimental and theoretical approaches for studying quarkonium at high energies.

Findings

Discovery of many new quarkonium states, including charged exotic hadrons.

High-precision measurements of quarkonium production at large transverse momentum.

Recent theoretical frameworks for inclusive quarkonium production.

Abstract

In this Snowmass White Paper, we discuss physics opportunities involving heavy quarkonia at the intensity and energy frontiers of high energy physics. We focus primarily on two specific aspects of quarkonium physics for which significant advances can be expected from experiments at both frontiers. The first aspect is the spectroscopy of charmonium and bottomonium states above the open-heavy-flavor thresholds. Experiments at e^+ e^- colliders and at hadron colliders have discovered many new, unexpected quarkonium states in the last 10 years. Many of these states are surprisingly narrow, and some have electric charge. The observations of these charged quarkonium states are the first definitive discoveries of manifestly exotic hadrons. These results challenge our understanding of the QCD spectrum. The second aspect is the production of heavy quarkonium states with large transverse momentum. Experiments at the LHC are measuring quarkonium production with high statistics at unprecedented values of p_T. Recent theoretical developments may provide a rigorous theoretical framework for inclusive production of quarkonia at large p_T. Experiments at the energy frontier will provide definitive tests of this framework. Experiments at the intensity frontier also provide an opportunity to understand the exclusive production of quarkonium states.