Journal Article

FZJ-2015-03424

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Nucleon axial charge and pion decay constant from two-flavor lattice QCD

Horsley, R. ; Nakamura, Y. ; Nobile, A.FZJ* ; Rakow, P. E. L. ; Schierholz, G. (Corresponding Author) ; Zanotti, J. M.

2014
North-Holland Publ. Amsterdam

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Please use a persistent id in citations: http://hdl.handle.net/2128/8776  doi:10.1016/j.physletb.2014.03.002

Abstract: The axial charge of the nucleon gAgA and the pion decay constant fπfπ are computed in two-flavor lattice QCD. The simulations are carried out on lattices of various volumes and lattice spacings. Results are reported for pion masses as low as mπ=130 MeVmπ=130 MeV. Both quantities, gAgA and fπfπ, suffer from large finite size effects, which to leading order ChEFT and ChPT turn out to be identical. By considering the naturally renormalized ratio gA/fπgA/fπ, we observe a universal behavior as a function of decreasing quark mass. From extrapolating the ratio to the physical point, we find View the MathML sourcegAR=1.29(5)(3), using the physical value of fπfπ as input and r0=0.50(1)r0=0.50(1) to set the scale. In a subsequent calculation we attempt to extrapolate gAgA and fπfπ separately to the infinite volume. Both volume and quark mass dependencies of gAgA and fπfπ are found to be well described by ChEFT and ChPT. We find at the physical point View the MathML sourcegAR=1.24(4) and View the MathML sourcefπR=89.6(1.1)(1.8) MeV. Both sets of results are in good agreement with experiment. As a by-product we obtain the low-energy constant View the MathML sourcel¯4=4.2(1).

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Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)
2. Quanten-Theorie der Materialien (IAS-1)

Research Program(s):

1. 411 - Computational Science and Mathematical Methods (POF2-411) (POF2-411)

Appears in the scientific report 2015

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Database coverage:
; ; ; Current Contents - Physical, Chemical and Earth Sciences ; IF >= 5 ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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