Lattice simulations for the running coupling constant of QCD

TL;DR

This paper reviews lattice QCD methods for precisely calculating the strong coupling constant alpha_s over a wide range of energy scales, aiming to detect potential deviations from expected running behavior.

Contribution

It provides a comprehensive overview of recent lattice QCD techniques for determining alpha_s in both quenched and full QCD, highlighting advancements in precision.

Findings

Lattice QCD can now determine alpha_s with accuracy comparable to experiments.

Recent calculations cover a broad range of energy scales.

Potential for detecting anomalous running of the strong coupling.

Abstract

The strong coupling constant alpha_s(mu_0), taken at a fixed reference scale mu_0, is the single free parameter of QCD and should be known to the highest available precision. The value of alpha_s should also be determined with good accuracy over as large a range of scales as possible, in order to reveal potential anomalous running in the strength of the strong interaction. Lattice QCD is now able to calculate alpha_s with accuracy comparable to or better than experiment. We review the status of such lattice calculations in quenched and full QCD.