% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Bali:21703, author = {Bali, G.S. and Collins, S. and Göckeler, M. and Horsley, R. and Nakamura, Y. and Nobile, A. and Pleiter, D. and Rakow, P.E.L. and Sternbeck, A. and Schäfer, A. and Schierholz, G. and Zanotti, J.M.}, title = {{A} lattice study of the strangeness content of the nucleon}, journal = {Progress in particle and nuclear physics}, volume = {67}, issn = {0146-6410}, address = {Oxford [u.a.]}, publisher = {Pergamon Press}, reportid = {PreJuSER-21703}, pages = {467 - 472}, year = {2012}, note = {This work was supported by the European Union (grant 238353, ITN STRONGnet) and by the DFG SFB/Transregio 55. S.C. is supported by the Claussen-Simon-Foundation (Stifterverband fur die Deutsche Wissenschaft), A.St. by the EU IRG grant 256594 and J.Z. by the Australian Research Council grant FT100100005. Computations were performed on the SFB/TR55 QPACE supercomputers, the BlueGene/P (JuGene) and the Nehalem cluster (JuRoPA) of the JSC (Julich), 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 [24] was used extensively in this work.}, abstract = {We determine the quark contributions to the nucleon spin Delta s, Delta u and Ad as well as their contributions to the nucleon mass, the a-terms. This is done by computing both, the quark line connected and disconnected contributions to the respective matrix elements, using the non-perturbatively improved Sheikholeslami-Wohlert Wilson Fermionic action. We simulate n(F) = 2 mass degenerate sea quarks with a pion mass of about 285 MeV and a lattice spacing a approximate to 0.073 fm. The renormalization of the matrix elements involves mixing between contributions from different quark flavours. The pion-nucleon a-term is extrapolated to physical quark masses exploiting the sea quark mass dependence of the nucleon mass. We obtain the renormalized value sigma(pi N) = (38 +/- 12) MeV at the physical point and the strangeness fraction f(Ts) = sigma s/m(N) = 0.012(14)(-3)(+10) at our larger than physical sea quark mass. For the strangeness contribution to the nucleon spin we obtain Delta s ((MS)) over bar(root 7.4 GeV) = -0.020(10)(1). (C) 2012 Published by Elsevier B.V.}, keywords = {J (WoSType)}, cin = {JSC}, ddc = {530}, cid = {I:(DE-Juel1)JSC-20090406}, pnm = {Scientific Computing (FUEK411) / 411 - Computational Science and Mathematical Methods (POF2-411) / STRONGNET - Strong Interaction Supercomputing Training Network (238353) / PRECISION LATTICEQCD - Precision lattice QCD calculations (256594)}, pid = {G:(DE-Juel1)FUEK411 / G:(DE-HGF)POF2-411 / G:(EU-Grant)238353 / G:(EU-Grant)256594}, shelfmark = {Physics, Nuclear / Physics, Particles $\&$ Fields}, typ = {PUB:(DE-HGF)16}, UT = {WOS:000303282200062}, doi = {10.1016/j.ppnp.2012.01.012}, url = {https://juser.fz-juelich.de/record/21703}, }