Abstract
We compute the strangeness and light-quark contributions Δs, Δu, and Δd to the proton spin in nf=2 lattice QCD at a pion mass of about 285 MeV and at a lattice spacing a≈0.073fm, 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 ΔsMS¯(7.4GeV)=-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.
Original language | English |
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Pages (from-to) | 222001 |
Number of pages | 5 |
Journal | Physical Review Letters |
Volume | 108 |
Issue number | 22 |
DOIs | |
Publication status | Published - 30 May 2012 |