Journal Article

PreJuSER-19010

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Strangeness Contribution to the Proton Spin from Lattice QCD

Bali, G. S. ; Collins, S. ; Göckeler, M. ; Horsley, R. ; Nakamura, Y. ; Nobile, A.FZJ* ; Pleiter, D.FZJ* ; Rakow, P. E. L. ; Schäfer, A. ; Schierholz, G. ; Zanotti, J. M.

2012
APS College Park, Md.

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Please use a persistent id in citations: http://hdl.handle.net/2128/7379  doi:10.1103/PhysRevLett.108.222001

Abstract: We compute the strangeness and light-quark contributions Delta s, Delta u, and Delta d to the proton spin in n(f) = 2 lattice QCD at a pion mass of about 285 MeV and at a lattice spacing a approximate to 0.073 fm, using the nonperturbatively improved Sheikholeslami-Wohlert Wilson action. We carry out the renormalization of these matrix elements, which involves mixing between contributions from different quark flavors. Our main result is the small negative value Delta s((MS) over bar)(root 7.4 GeV) = -0.020(10)(4) of the strangeness contribution to the nucleon spin. The second error is an estimate of the uncertainty, due to the missing extrapolation to the physical point.

Keyword(s): J

Note: This work is supported by the EU (Grant No. 238353, ITN STRONGnet) and by the DFG Grant No. SFB/TR55. S. C. acknowledges support from the Claussen-Simon-Foundation (Stifterverband fur die Deutsche Wissenschaft) and J. Z. from the Australian Research Council (Grant No. FT100100005). Computations were performed on the SFB/TR55 QPACE supercomputers, the BlueGene/P (JuGene) and the Nehalem Cluster (JuRoPA) of the Julich Supercomputer Center, the IBM BlueGene/L at the EPCC (Edinburgh), the SGI Altix ICE machines at HLRN (Berlin/Hannover), and Regensburg's Athene HPC cluster. The CHROMA software suite [33] was used and gauge configurations were generated with the BQCD code [34].

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Contributing Institute(s):

1. Jülich Supercomputing Centre (JSC)

Research Program(s):

1. Scientific Computing (FUEK411) (FUEK411)
2. 411 - Computational Science and Mathematical Methods (POF2-411) (POF2-411)
3. STRONGNET - Strong Interaction Supercomputing Training Network (238353) (238353)

Appears in the scientific report 2012

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Database coverage:
; ; ; Current Contents - Social and Behavioral Sciences ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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