Flavor singlet axial vector coupling of the proton with dynamical Wilson fermions - art. no. 114502.

We present the results of a full QCD lattice calculation of the flavor sing let axial vector coupling G(A)(1) of the proton. The simulation has been ca rried out on a 16(3)X32 lattice at beta=5.6 with n(f)=2 dynamical Wilson fe rmions. It turns out that the statistical quality of the connected contribu tion to G(A)(1) is excellent, whereas the disconnected part is accessible b ut suffers from large statistical fluctuations. Using a 1st order tadpole i mproved renormalization constant Z(A), we estimate G(A)(1)=0.20(12). [S0556 -2821(99)04811-0].