Large pion pole in ZSMOM/ZPMOM from Wilson action data

Abstract We show that, contrarily to recent claims, data from the Wilson (unimproved) fermionic action at three different β values demonstrate the presence of a large Goldstone boson contribution in the quark pseudoscalar vertex, quantitatively close to our previous estimate based on the SW action with c SW =1.769. We show that discretisation errors on Z S MOM / Z P MOM seem to be much smaller than the Goldstone pole contribution over a very large range of momenta. The subtraction of this non perturbative contribution leads to numbers close to one-loop BPT.