Talk presented by Carlotta Pittori

Parallel Session: Improvement and Renormalization I

Tuesday June 29th, 15.30 - 15.50, Room B

Pseudoscalar Vertex and Quark Masses

Abstract: We analyse available data on the quark pseudoscalar vertex and extract the contribution of the Goldstone boson pole. The strength of the pole is found to be quite large at presently accessible scales. We draw the important consequences of this finding for the various definitions of quark masses. Indeed, the Goldstone boson leads to a large non-perturbative contribution to the quark renormalised mass function \`a la Georgi and Politzer, larger than what is expected from the quark condensate and from the perturbative evaluation of the Wilson coefficient. Moreover, it is essential to subtract this Goldstone boson contribution from the pseudoscalar vertex in order to calculate the short-distance masses of the light quarks.

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