High-precision calculation of the quark-gluon coupling from lattice QCD

Area of Science:

• Particle Physics
• Quantum Chromodynamics
• Strong Nuclear Force

Background:

• Modern particle physics experiments rely on accurate descriptions of fundamental forces.
• The strong nuclear force, described by quantum chromodynamics (QCD), presents challenges due to quark confinement, leading to significant theoretical uncertainties in determining its coupling constant, αs.
• Existing methods for determining αs often require model assumptions, limiting precision.

Purpose of the Study:

• To achieve a model-free determination of the strong coupling constant, αs, with unprecedented precision.
• To reduce systematic theory errors in particle physics calculations.
• To provide a more accurate αs value that benefits both low-energy hadronic physics and high-energy scattering experiments.

Main Methods:

• Employed large-scale numerical simulations of the first-principles formulation of quantum chromodynamics on a space-time lattice.
• Combined low-energy experimental input with lattice QCD calculations.
• Utilized a Monte Carlo evaluation with a clear probabilistic interpretation for uncertainty quantification.

Main Results:

• Reported a model-free determination of αs with significantly reduced uncertainty compared to previous results.
• The achieved precision is approximately half that of all other combined results.
• The determined αs value consistently describes both low-energy hadronic physics and high-energy scattering phenomena.

Conclusions:

• The precise, model-free determination of αs removes a major source of theoretical uncertainty in particle physics.
• This improved value of αs will enable more accurate analyses of high-energy experiments, potentially revealing new physics.
• The findings facilitate stringent precision tests of the Standard Model and enhance the search for physics beyond it.