Manifestation of Sea Quark Effects in the Strong Coupling Constant in Lattice QCD

TL;DR

This paper shows that sea quark effects significantly influence the strong coupling constant in lattice QCD and provides an estimate of _{ ext{MS}}^{(5)}(M_Z) using charmonium mass splittings from full QCD simulations.

Contribution

It demonstrates the visibility of sea quark effects in the strong coupling constant and estimates _{ ext{MS}}^{(5)}(M_Z) from lattice QCD data.

Findings

Sea quark effects are clearly visible in the strong coupling constant.

An estimate of _{ ext{MS}}^{(5)}(M_Z) is obtained from lattice QCD simulations.

The charmonium 1S-1P mass splitting effectively fixes the scale.

Abstract

We demonstrate that sea quark effects of a magnitude expected from renormalization group considerations are clearly visible in the strong coupling constant measured in current full QCD simulations. Building on this result an estimate of $\alpha_{\overline{MS}}^{(5)}(M_Z)$ is made employing the charmonium $1S-1P$ mass splitting calculated on full QCD configurations generated with two flavors of dynamical Kogut-Susskind quarks to fix the scale.