FIZIKA B 14 (2005)  1, 13 - 30

 CIRCUMVENTING THE AXIAL ANOMALIES AND THE STRONG CP PROBLEM

DALIBOR KEKEZ^a, DUBRAVKO KLABUČAR^b and M. D. SCADRON^c

^aRuđer Bošković Institute, P.O.B. 180, 10002 Zagreb, Croatia
^bPhysics Department, Faculty of Science, University of Zagreb, P.O.B. 331, 10002 Zagreb, Croatia
^cPhysics Department, University of Arizona, Tucson AZ 85721 U.S.A.

Paper devoted to honour the memory of Professor Dubravko Tadić

Received 10 February 2005;    Accepted 2 May 2005
Online 31 October 2005

Many meson processes are related to the U_A(1) axial anomaly, present in the Feynman graphs where fermion loops connect axial vertices with vector vertices. However, the coupling of pseudoscalar mesons to quarks does not have to be formulated via axial vertices. The pseudoscalar coupling is also possible, and this approach is especially natural on the level of the quark substructure of hadrons. In this paper we point out the advantages of calculating these processes using (instead of the anomalous graphs) the graphs where axial vertices are replaced by pseudoscalar vertices. We elaborate especially the case of the processes related to the Abelian axial anomaly of QED, but we speculate that it seems possible that effects of the non-Abelian axial anomaly of QCD can be accounted for in an analogous way.

PACS numbers: 14.40.-n, 12.39.Fe, 13.20.-v, 11.10.St
UDC 529.126

Keywords: anomaly, quark loops, radiative and hadronic decays of mesons

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