Is eta' partially made of gluonium?

Abstract

A phenomenological analysis of radiative $V\to Pγ$ and $P\to Vγ$ decays is performed in order to determine the gluonic content of the $η^\prime$ wave function. Our result shows that there is no evidence for such a gluonium contribution, $Z_{η^\prime}^2=0.04\pm 0.09$. In terms of a mixing angle description this corresponds to $ϕ_P=(41.4\pm 1.3)^\circ$ and $|ϕ_{η^\prime G}|=(12\pm 13)^\circ$.

8 pages, 2 figures, uses frascatiphys style. Talk presented at the XII International Conference on Hadron Spectroscopy (HADRON 07), Laboratori Nazionali di Frascati (Rome), Italy, 8-13 October 2007