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QCD coupling and heavy-quark masses from (2+1)-flavor lattice QCD simulations
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The QCD running coupling (or emergent QCD scale Lambda) is a key parameter whose uncertainty is often a limiting factor in searches for physics beyond the Standard Model. While there are very few experimental determinations of the QCD running coupling at low energy scales (1 GeV < Q < 10 GeV), lattice QCD is an ideal tool that tests perturbative QCD in that regime and provides complementary information.
I discuss lattice determinations of the QCD coupling constant (and charm and bottom quark masses) using two different methods, the moments of quarkonium correlators and the QCD static quark-antiquark energy. For both methods I focus on the challenges of obtaining a continuum limit of the lattice observables, and of properly accounting for the uncertainty due to the truncation of perturbation theory. After reviewing lattice results obtained with these two methods I obtain a lattice world average for the strong coupling constant.
References:
1. Strong coupling constant from moments of quarkonium correlators revisited
P. Petreczky, J.H. Weber,
arXiv:2012.06193
2. Strong coupling constant and quark masses from lattice QCD
J. Komijani, P. Petreczky, J.H. Weber,
Prog.Part.Nucl.Phys. 113 (2020) 103788
3. Determination of the QCD coupling from the static energy and the free energy
A. Bazavov, N. Brambilla, X. Garcia i Tormo, P. Petrezcky, J. Soto, A. Vairo, J.H. Weber [TUMQCD],
Phys.Rev.D 100 (2019) 11, 114511
4. Strong coupling constant and heavy quark masses in (2+1)-flavor QCD
P. Petreczky, J.H. Weber,
Phys.Rev.D 100 (2019) 3, 034519
5. Determination of αs\alpha_sαs from the QCD static energy: An update
A. Bazavov, N. Brambilla, X. Garcia i Tormo, P. Petrezcky, J. Soto, A. Vairo
Phys.Rev.D 90 (2014) 7, 074038