Axial anomaly and low energy tests
for instanton vacuum models in QCD
1 Dipartimento di Fisica, Universitá di Genova,
via Dodecaneso, 33, I-16146 Genova, Italy
2 Research Center for Nuclear Physics, Osaka University, Mihogaoko 10-1, Ibaraki, Osaka 567, Japan
(e-mail: firstname.lastname@example.org, email@example.com)
Received: 24 November 1997 / Published online: 10 March 1998
We propose to test instanton models of QCD - in particular the single instanton approximation and the Diakonov and Petrov model - against some exact relations inferred from QCD + QED axial anomaly. One of these relations, in chiral limit, is satisfied by the latter model, but not by the former one. More refined tests, obtained beyond the chiral limit, are not fulfilled by the Diakonov and Petrov model.