Error reduction technique using covariant approximation and application to nucleon form factor

Abstract

We demonstrate the new class of variance reduction techniques for hadron propagator and nucleon isovector form factor in the realistic lattice of Nf = 2+1 domain-wall fermion. All-mode averaging (AMA) is one of the powerful tool to more effectively reduce the statistical noise of various observables rather than low-mode averaging (LMA). We adopt this technique into the two-point function and three-point function, and comparing with LMA and traditional source-shift method in the same ensembles we see AMA has much advantage of performance for these observables.