Quarkonium Decays and Production in NRQCD

TL;DR

This paper reviews recent applications of NRQCD to quarkonium decays and production, comparing theoretical calculations with experimental data and exploring the extraction of non-perturbative matrix elements.

Contribution

It provides a critical analysis of NLO calculations for quarkonium decay rates and demonstrates how to extract and test the universality of non-perturbative matrix elements from experiments.

Findings

NLO calculations for $ ext{χ}_cJ$ and $ ext{Υ}$ decay rates agree with data

Extraction of non-perturbative matrix elements from fixed-target experiments

Testing the universality of matrix elements across different processes

Abstract

Some examples of the most recent applications of the NRQCD factorization approach to quarkonium phenomenology are presented. In the first part of the talk the NLO calculations for $\chicj$ and $\Upsilon$ decays rates are compared to the data and the results critically analyzed. In the second part, I show how information on the non-perturbative matrix elements can be extracted from the hadronic fixed-target experiments and eventually used to test their universality.