Study of the η-η′ system in the two mixing angle -: art. no. 029

An analysis of various decay processes is performed using the two mixing angle description of the eta-eta' system, incorporating the link to the gluonic sector through anomalies. The agreement is excellent. For comparison with previous works, our results are expressed both in the "octet- singlet" and in the "quark-favour" basis. It turns out that at the present experimental accuracy, the two angles are significantly different in the former, but not in the latter basis. The implications of our analysis for the large N-c chi PT predictions are also discussed.