Radiative VPγ transitions and η-η′ mixing

A value for the eta-eta ' mixing angle is extracted from the data on V P gamma transitions using simple quark-model ideas. The set of data covers all possible radiative transitions between the pseudoscalar and vector meson nonets. Two main ingredients of the model are the introduction of flavour-dependent overlaps for the various q (q) over bar wave functions and the use of the quark-flavour basis to describe the eta-eta ' system. In this basis the mixing angle is found to be phi (P) = (37.7 +/- 2.4)degrees. (C) 2001 Published by Elsevier Science B.V.