A review of heavy-heavy spectroscopy

TL;DR

This review discusses recent advances in heavy-heavy spectroscopy calculations using lattice QCD, highlighting successful methods, improved accuracy, and key results like precise quark mass and lattice spacing determinations.

Contribution

It provides a comprehensive overview of the latest lattice techniques for heavy-heavy spectra and reports new precise measurements of the b quark mass and lattice spacing.

Findings

Lattice methods for heavy-heavy spectra are effective and systematically improvable.

Perturbation theory in these methods is well-behaved.

Accurate determination of the b quark mass and lattice spacing.

Abstract

Calculations of the heavy-heavy spectrum present a good opportunity for precision tests of QCD using lattice techniques. All methods make use of a non-relativistic expansion of the action and its systematic improvement to remove lattice artefacts. There was convincing demonstration this year that these methods work and that the associated perturbation theory is well-behaved. Comparison to experimental results yields an accurate value for the lattice spacing, a, a key result in the determination of \alpha_{s}, and (for the first time this year) the mass of the b quark (4.7(1) GeV).