We report results of our calculation on the π N σ term and quark spin content of the nucleon on the quenched 163 × 24 lattice at β = 6.0. The disconnected insertions which involve contributions from the sea quarks are calculated with the stochastic Z2 noise algorithm. As a physical test of the algorithm, we show that the forward matrix elements of the vector and pseudoscalar currents for the disconnected insertions are indeed consistent with the known results of zero. We tried the Wuppertal smeared source and found it to be more noisy than the point source. With unrenormalized mq = 4.42(17)MeV, we find the π N σ term to be 39.2 ± 5.2 MeV. The strange quark condensate in the nucleon is large, i.e. 〈 N | over(s, -) s | N 〉 = 1.16 ± 0.54. For the quark spin content, we find Δu = 0.78 ± 0.07, Δd = -0.42 ± 0.07, and Δs = -0.13 ± 0.06. The flavor-singlet axial charge gA1 = ΔΣ = 0.22 ± 0.09.
|Number of pages||3|
|Journal||Nuclear Physics B - Proceedings Supplements|
|State||Published - Apr 1995|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics