Nucleon Structure from Lattice QCD

Abstract

We report results on the nucleon structure obtained from the lattice quantum chromodynamics calculation. These include the axial, electromagnetic, $\pi NN$, and scalar form factors. The calculation is carried out at $\beta = 6$ on a $16^3 \times 24$ lattice with 24 quenched gauge configurations. The chiral limit results are extrapolated from several light quark cases. For the disconnected insertion (sea-quark contribution), we used the stochastic estimation with the $Z_2$ noise to calculate the diagonal and off-diagonal traces of the inverse matrices with a size of $10^6 \times 10^6$. It is found that the $Z_2$ noise is the optimal choice and its comparison with the Gaussian noise for our quark matrix is given. For the sea-quark contribution, we report results on the strange condensate in the nucleon and the $\pi N \sigma$ term.