Nucleon axial coupling from Lattice QCD
| Autor: | Chang, Chia Cheng, Nicholson, Amy, Rinaldi, Enrico, Berkowitz, Evan, Garron, Nicolas, Brantley, David, Monge-Camacho, Henry, Monahan, Chris, Bouchard, Chris, Clark, M. A., Joo, Balint, Kurth, Thorsten, Orginos, Kostas, Vranas, Pavlos, Walker-Loud, Andre |
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| Rok vydání: | 2017 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We present state-of-the-art results from a lattice QCD calculation of the nucleon axial coupling, $g_A$, using M\"obius Domain-Wall fermions solved on the dynamical $N_f = 2 + 1 + 1$ HISQ ensembles after they are smeared using the gradient-flow algorithm. Relevant three-point correlation functions are calculated using a method inspired by the Feynman-Hellmann theorem, and demonstrate significant improvement in signal for fixed stochastic samples. The calculation is performed at five pion masses of $m_\pi\sim \{400, 350, 310, 220, 130\}$~MeV, three lattice spacings of $a\sim\{0.15, 0.12, 0.09\}$~fm, and we do a dedicated volume study with $m_\pi L\sim\{3.22, 4.29, 5.36\}$. Control over all relevant sources of systematic uncertainty are demonstrated and quantified. We achieve a preliminary value of $g_A = 1.285(17)$, with a relative uncertainty of 1.33\%. Comment: 18 pages, 8 figures, Lattice 2017 Proceedings |
| Databáze: | arXiv |
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