1012.0562 (Ronald Babich et al.)

Exploring strange nucleon form factors on the lattice    [PDF]

Ronald Babich, Richard C. Brower, Michael A. Clark, George T. Fleming, James C. Osborn, Claudio Rebbi, David Schaich

We discuss techniques for evaluating sea quark contributions to hadronic form factors on the lattice and apply these to an exploratory calculation of the strange electromagnetic, axial, and scalar form factors of the nucleon. We employ the Wilson gauge and fermion actions on an anisotropic 24^3 x 64 lattice, probing a range of momentum transfer with Q^2 < 1 GeV^2. The strange electric and magnetic form factors, G_E^s(Q^2) and G_M^s(Q^2), are found to be small and consistent with zero within the statistics of our calculation. The lattice data favor a small negative value for the strange axial form factor G_A^s(Q^2) and exhibit a strong signal for the bare strange scalar matrix element _0. We discuss the unique systematic uncertainties affecting the latter quantity relative to the continuum, as well as prospects for improving future determinations with Wilson-like fermions.

View original: http://arxiv.org/abs/1012.0562