Running coupling constant from position-space current-current correlation functions in three-flavor lattice QCD
| Autor: | Cali, Salvatore, Cichy, Krzysztof, Korcyl, Piotr, Simeth, Jakob |
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| Rok vydání: | 2020 |
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| Zdroj: | Phys. Rev. Lett. 125, 242002 (2020) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.125.242002 |
| Popis: | In this Letter, we provide a determination of the coupling constant in three-flavor quantum chromodynamics (QCD), $\alpha^{\overline{\mathrm{MS}}}_s(\mu)$, for $\overline{\mathrm{MS}}$ renormalization scales $\mu \in (1,\,2)$ GeV. The computation uses gauge field configuration ensembles with $\mathcal{O}(a)$-improved Wilson-clover fermions generated by the Coordinated Lattice Simulations (CLS) consortium. Our approach is based on current-current correlation functions and has never been applied before in this context. We convert the results perturbatively to the QCD $\Lambda$-parameter and obtain $\Lambda_{\overline{\mathrm{MS}}}^{N_f=3} = 342 \pm 17$ MeV, which agrees with the world average published by the Particle Data Group and has competing precision. The latter was made possible by a unique combination of state-of-the-art CLS ensembles with very fine lattice spacings, further reduction of discretization effects from a dedicated numerical stochastic perturbation theory simulation, combining data from vector and axial-vector channels and matching to high-order perturbation theory. Comment: Matches version accepted for publication in Physical Review Letters. Extensive supplemental material added. Main manuscript: 6 pages, 4 figures. Supplemental material: 11 pages, 8 figures |
| Databáze: | arXiv |
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