Strangeness Contribution to the Proton Spin from Lattice QCD
Abstract
We compute the strangeness and light-quark contributions Delta s, Delta u and Delta d to the proton spin in nf=2 lattice QCD at a pion mass of about 285 MeV and at a lattice spacing a approx 0.073 fm, using the non-perturbatively improved Sheikholeslami-Wohlert Wilson action. We carry out the renormalization of these matrix elements which involves mixing between contributions from different quark flavours. Our main result is the small negative value MSbar scheme value Delta s = -0.020(10)(4), at a scale mu = 7.4 GeV, 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.
Keywords
Cite
@article{arxiv.1112.3354,
title = {Strangeness Contribution to the Proton Spin from Lattice QCD},
author = {Gunnar S. Bali and Sara Collins and Meinulf Gockeler and Roger Horsley and Yoshifumi Nakamura and Andrea Nobile and Dirk Pleiter and P. E. L. Rakow and Andreas Schafer and Gerrit Schierholz and James M. Zanotti},
journal= {arXiv preprint arXiv:1112.3354},
year = {2012}
}
Comments
5 pages, 2 figures, V2: minor changes, to enhance the readability of the article. References updated. "The" removed from the title