Partial widths for the decays $\eta(1295)\to\gamma\gamma$ and $\eta(1440)\to\gamma\gamma$

A.V. Anisovich; V.V. Anisovich; V.A. Nikonov; L. Montanet

doi:doi:10.1007/s100500050342

EPJ

Partial widths for the decays $\eta(1295)\to\gamma\gamma$ and $\eta(1440)\to\gamma\gamma$

A.V. Anisovich¹ - V.V. Anisovich¹ - V.A. Nikonov¹ - L. Montanet²

¹ St.Petersburg Nuclear Physics Institute, Gatchina, 188350, Russia
² CERN, 1211 Geneva 23, Switzerland

Received: 24 September 1999 Communicated by B. Povh

Abstract
We discuss $\gamma\gamma$ partial widths of pseudoscalar/isoscalar mesons $\eta(M)$ in the mass region $M\sim 1000-1500$ MeV. The transition amplitudes $\eta(1295)\to\gamma\gamma$ and $\eta(1440)\to\gamma\gamma$ are studied within an assumption that the decaying mesons are the members of the first radial excitation nonet $2^1S_0q\bar q$ . The calculations show that partial widths being of the order of 0.1 keV are dominantly due to the $n\bar n$ meson component while the contribution of the $s\bar s$ component is small.